Network Working Group F. Baker
Request for Comments: 3289 Cisco System
Category: Standards Track K. Chan
Nortel Networks
A. Smith
Harbour Networks
May 2002
Management Information Base for the
Differentiated Services Architecture
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Abstract
This memo describes an SMIv2 (Structure of Management Information
version 2) MIB for a device implementing the Differentiated Services
Architecture. It may be used both for monitoring and configuration
of a router or switch capable of Differentiated Services
functionality.
Table of Contents
1 The SNMP Management Framework ................................. 3
2 Relationship to other working group documents ................. 4
2.1 Relationship to the Informal Management Model for
Differentiated Services Router ............................. 4
2.2 Relationship to other MIBs and Policy Management ............ 5
3 MIB Overview .................................................. 6
3.1 Processing Path ............................................. 7
3.1.1 diffServDataPathTable - The Data Path Table ............... 7
3.2 Classifier .................................................. 7
3.2.1 diffServClfrElementTable - The Classifier Element Table ... 8
3.2.2 diffServMultiFieldClfrTable - The Multi-field Classifier
Table ...................................................... 9
3.3 Metering Traffic ............................................ 10
3.3.1 diffServMeterTable - The Meter Table ...................... 11
3.3.2 diffServTBParamTable - The Token Bucket Parameters Table... 11
3.4 Actions applied to packets .................................. 12
3.4.1 diffServActionTable - The Action Table .................... 12
3.4.2 diffServCountActTable - The Count Action Table ............ 12
3.4.3 diffServDscpMarkActTable - The Mark Action Table .......... 13
3.4.4 diffServAlgDropTable - The Algorithmic Drop Table ......... 13
3.4.5 diffServRandomDropTable - The Random Drop Parameters Table 14
3.5 Queuing and Scheduling of Packets ........................... 16
3.5.1 diffServQTable - The Class or Queue Table ................. 16
3.5.2 diffServSchedulerTable - The Scheduler Table .............. 16
3.5.3 diffServMinRateTable - The Minimum Rate Table ............. 16
3.5.4 diffServMaxRateTable - The Maximum Rate Table ............. 17
3.5.5 Using queues and schedulers together ...................... 17
3.6 Example configuration for AF and EF ......................... 20
3.6.1 AF and EF Ingress Interface Configuration ................. 20
3.6.1.1 Classification In The Example ........................... 22
3.6.1.2 AF Implementation On an Ingress Edge Interface .......... 22
3.6.1.2.1 AF Metering On an Ingress Edge Interface .............. 22
3.6.1.2.2 AF Actions On an Ingress Edge Interface ............... 23
3.6.1.3 EF Implementation On an Ingress Edge Interface .......... 23
3.6.1.3.1 EF Metering On an Ingress Edge Interface .............. 23
3.6.1.3.2 EF Actions On an Ingress Edge Interface ............... 23
3.7 AF and EF Egress Edge Interface Configuration ............... 24
3.7.1 Classification On an Egress Edge Interface ................ 24
3.7.2 AF Implementation On an Egress Edge Interface ............. 26
3.7.2.1 AF Metering On an Egress Edge Interface ................. 26
3.7.2.2 AF Actions On an Egress Edge Interface .................. 29
3.7.2.3 AF Rate-based Queuing On an Egress Edge Interface ....... 30
3.7.3 EF Implementation On an Egress Edge Interface ............. 30
3.7.3.1 EF Metering On an Egress Edge Interface ................. 30
3.7.3.2 EF Actions On an Egress Edge Interface .................. 30
3.7.3.3 EF Priority Queuing On an Egress Edge Interface ......... 32
4 Conventions used in this MIB .................................. 33
4.1 The use of RowPointer to indicate data path linkage ......... 33
4.2 The use of RowPointer to indicate parameters ................ 34
4.3 Conceptual row creation and deletion ........................ 34
5 Extending this MIB ............................................ 35
6 MIB Definition ................................................ 35
7 Acknowledgments ............................................... 110
8 Security Considerations ....................................... 110
9 Intellectual Property Rights .................................. 111
10 References ................................................... 112
11 Authors' Addresses ........................................... 115
12 Full Copyright Statement ..................................... 116
1. The SNMP Management Framework
The SNMP Management Framework presently consists of five major
components:
o An overall architecture, described in [RFC 2571].
o Mechanisms for describing and naming objects and events for the
purpose of management. The first version of this Structure of
Management Information (SMI) is called SMIv1 and is described
in [RFC 1155], [RFC 1212] and [RFC 1215]. The second version,
called SMIv2, is described in [RFC 2578], RFC 2579 [RFC 2579]
and [RFC 2580].
o Message protocols for transferring management information. The
first version of the SNMP message protocol is called SNMPv1 and
is described in [RFC 1157]. A second version of the SNMP
message protocol, which is not an Internet standards track
protocol, is called SNMPv2c and is described in [RFC 1901] and
[RFC 1906]. The third version of the message protocol is
called SNMPv3 and is described in [RFC 1906], [RFC 2572] and
[RFC 2574].
o Protocol operations for accessing management information. The
first set of protocol operations and associated PDU formats is
described in [RFC 1157]. A second set of protocol operations
and associated PDU formats is described in [RFC 1905].
o A set of fundamental applications described in [RFC 2573] and
the view-based access control mechanism described in [RFC
2575].
A more detailed introduction to the current SNMP Management Framework
can be found in [RFC 2570].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. Objects in the MIB are
defined using the mechanisms defined in the SMI.
This memo specifies a MIB module that is compliant to the SMIv2. A
MIB conforming to the SMIv1 can be produced through the appropriate
translations. The resulting translated MIB must be semantically
equivalent, except where objects or events are omitted because there
is no translation is possible (use of Counter64). Some machine-
readable information in SMIv2 will be converted into textual
descriptions in SMIv1 during the translation process. However, this
loss of machine readable information is not considered to change the
semantics of the MIB.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC 2119].
2. Relationship to other working group documents
The Differentiated Services Working Group and related working groups
developed other documents, notably the Informal Management Model and
the policy configuration paradigm of SNMPCONF. The relationship
between the MIB and those documents is clarified here.
2.1. Relationship to the Informal Management Model for Differentiated
Services Router
This MIB is similar in design to [MODEL], although it can be used to
build functional data paths that the model would not well describe.
The model conceptually describes ingress and egress interfaces of an
n-port router, which may find some interfaces at a network edge and
others facing into the network core. It describes the configuration
and management of a Differentiated Services interface in terms of one
or more Traffic Conditioning Blocks (TCB), each containing, arranged
in the specified order, by definition, zero or more classifiers,
meters, actions, algorithmic droppers, queues and schedulers.
Traffic may be classified, and classified traffic may be metered.
Each stream of traffic identified by a combination of classifiers and
meters may have some set of actions performed on it; it may have
dropping algorithms applied and it may ultimately be stored into a
queue before being scheduled out to its next destination, either onto
a link or to another TCB. At times, the treatment for a given packet
must have any of those elements repeated. [MODEL] models this by
cascading multiple TCBs, while this MIB describes the policy by
directly linking the functional data path elements.
The MIB represents this cascade by following the "Next" attributes of
the various elements. They indicate what the next step in
Differentiated Services processing will be, whether it be a
classifier, meter, action, algorithmic dropper, queue, scheduler or a
decision to now forward a packet.
The higher level concept of a TCB is not required in the
parameterization or in the linking together of the individual
elements, hence it is not used in the MIB itself and is only
mentioned in the text for relating the MIB with the [MODEL]. Rather,
the MIB models the individual elements that make up the TCBs.
This MIB uses the notion of a Data Path to indicate the
Differentiated Services processing a packet may experience. The Data
Path a packet will initially follow is an attribute of the interface
in question. The Data Path Table provides a starting point for each
direction (ingress or egress) on each interface. A Data Path Table
Entry indicates the first of possible multiple elements that will
apply Differentiated Services treatment to the packet.
2.2. Relationship to other MIBs and Policy Management
This MIB provides for direct reporting and manipulation of detailed
functional elements. These elements consist of a structural element
and one or more parameter-bearing elements. While this can be
cumbersome, it allows the reuse of parameters. For example, a
service provider may offer three varieties of contracts, and
configure three parameter elements. Each such data path on the
system may then refer to these sets of parameters. The
diffServDataPathTable couples each direction on each interface with
the specified data path linkage. The concept of "interface" is as
defined by InterfaceIndex/ifIndex of the IETF Interfaces MIB [IF-
MIB].
Other MIBs and data structure definitions for policy management
mechanisms, other than SNMP/SMIv2 are likely to exist in the future
for the purpose of abstracting the model in other ways. An example
is the Differentiated Services Policy Information Base, [DSPIB].
In particular, abstractions in the direction of less detailed
definitions of Differentiated Services functionality are likely e.g.
some form of "Per-Hop Behavior"-based definition involving a template
of detailed object values which is applied to specific instances of
objects in this MIB semi-automatically.
Another possible direction of abstraction is one using a concept of
"roles" (often, but not always, applied to interfaces). In this
case, it may be possible to re-use the object definitions in this
MIB, especially the parameterization tables. The Data Path table
will help in the reuse of the data path linkage tables by having the
interface specific information centralized, allowing easier
mechanical replacement of ifIndex by some sort of "roleIndex". This
work is ongoing.
The reuse of parameter blocks on a variety of functional data paths
is intended to simplify network management. In many cases, one could
also re-use the structural elements as well; this has the unfortunate
side-effect of re-using the counters, so that monitoring information
is lost. For this reason, the re-use of structural elements is not
generally recommended.
3. MIB Overview
The Differentiated Services Architecture does not specify how an
implementation should be assembled. The [MODEL] describes a general
approach to implementation design, or to user interface design. Its
components could, however, be assembled in a different way. For
example, traffic conforming to a meter might be run through a second
meter, or reclassified.
This MIB models the same functional data path elements, allowing the
network manager to assemble them in any fashion that meets the
relevant policy. These data path elements include Classifiers,
Meters, Actions of various sorts, Queues, and Schedulers.
In many of these tables, a distinction is drawn between the structure
of the policy (do this, then do that) and the parameters applied to
specific policy elements. This is to facilitate configuration, if
the MIB is used for that. The concept is that a set of parameters,
such as the values that describe a specific token bucket, might be
configured once and applied to many interfaces.
The RowPointer Textual Convention is therefore used in two ways in
this MIB. It is defined for the purpose of connecting an object to
an entry dynamically; the RowPointer object identifies the first
object in the target Entry, and in so doing points to the entire
entry. In this MIB, it is used as a connector between successive
functional data path elements, and as the link between the policy
structure and the parameters that are used. When used as a
connector, it says what happens "next"; what happens to classified
traffic, to traffic conforming or not conforming to a meter, and so
on. When used to indicate the parameters applied in a policy, it
says "specifically" what is meant; the structure points to the
parameters of its policy.
The use of RowPointers as connectors allows for the simple extension
of the MIB. The RowPointers, whether "next" or "specific", may point
to Entries defined in other MIB modules. For example, the only type
of meter defined in this MIB is a token bucket meter; if another type
of meter is required, another MIB could be defined describing that
type of meter, and diffServMeterSpecific could point to it.
Similarly, if a new action is required, the "next" pointer of the
previous functional datapath element could point to an Entry defined
in another MIB, public or proprietary.
3.1. Processing Path
An interface has an ingress and an egress direction, and will
generally have a different policy in each direction. As traffic
enters an edge interface, it may be classified, metered, counted, and
marked. Traffic leaving the same interface might be remarked
according to the contract with the next network, queued to manage the
bandwidth, and so on. As [MODEL] points out, the functional datapath
elements used on ingress and egress are of the same type, but may be
structured in very different ways to implement the relevant policies.
3.1.1. diffServDataPathTable - The Data Path Table
Therefore, when traffic arrives at an ingress or egress interface,
the first step in applying the policy is determining what policy
applies. This MIB does that by providing a table of pointers to the
first functional data path element, indexed by interface and
direction on that interface. The content of the
diffServDataPathEntry is a single RowPointer, which points to that
functional data path element.
When diffServDataPathStart in a direction on an interface is
undefined or is set to zeroDotZero, the implication is that there is
no specific policy to apply.
3.2. Classifier
Classifiers are used to differentiate among types of traffic. In the
Differentiated Services architecture, one usually discusses a
behavior aggregate identified by the application of one or more
Differentiated Services Code Points (DSCPs). However, especially at
network edges (which include hosts and first hop routers serving
hosts), traffic may arrive unmarked or the marks may not be trusted.
In these cases, one applies a Multi-Field Classifier, which may
select an aggregate as coarse as "all traffic", as fine as a specific
microflow identified by IP Addresses, IP Protocol, and TCP or UDP
ports, or variety of slices in between.
Classifiers can be simple or complex. In a core interface, one would
expect to find simple behavior aggregate classification to be used.
However, in an edge interface, one might first ask what application
is being used, meter the arriving traffic, and then apply various
policies to the non-conforming traffic depending on the Autonomous
System number advertising the destination address. To accomplish
such a thing, traffic must be classified, metered, and then
reclassified. To this end, the MIB defines separate classifiers,
which may be applied at any point in processing, and may have
different content as needed.
The MIB also allows for ambiguous classification in a structured
fashion. In the end, traffic classification must be unambiguous; one
must know for certain what policy to apply to any given packet.
However, writing an unambiguous specification is often tedious, while
writing a specification in steps that permits and excludes various
kinds of traffic may be simpler and more intuitive. In such a case,
the classification "steps" are enumerated; all classification
elements of one precedence are applied as if in parallel, and then
all classification elements of the next precedence.
This MIB defines a single classifier parameter entry, the Multi-field
Classifier. A degenerate case of this multi-field classifier is a
Behavior Aggregate classifier. Other classifiers may be defined in
other MIB modules, to select traffic from a given layer two neighbor
or a given interface, traffic whose addresses belong to a given BGP
Community or Autonomous System, and so on.
3.2.1. diffServClfrElementTable - The Classifier Element Table
A classifier consists of classifier elements. A classifier element
identifies a specific set of traffic that forms part of a behavior
aggregate; other classifier elements within the same classifier may
identify other traffic that also falls into the behavior aggregate.
For example, in identifying AF traffic for the aggregate AF1, one
might implement separate classifier elements for AF11, AF12, and AF13
within the same classifier and pointing to the same subsequent meter.
Generally, one would expect the Data Path Entry to point to a
classifier (which is to say, a set of one or more classifier
elements), although it may point to something else when appropriate.
Reclassification in a functional data path is achieved by pointing to
another Classifier Entry when appropriate.
A classifier element is a structural element, indexed by classifier
ID and element ID. It has a precedence value, allowing for
structured ambiguity as described above, a "specific" pointer that
identifies what rule is to be applied, and a "next" pointer directing
traffic matching the classifier to the next functional data path
element. If the "next" pointer is zeroDotZero, the indication is
that there is no further differentiated services processing for this
behavior aggregate. However, if the "specific" pointer is
zeroDotZero, the device is misconfigured. In such a case, the
classifier element should be operationally treated as if it were not
present.
When the MIB is used for configuration, diffServClfrNextFree and
diffServClfrElementNextFree always contain legal values for
diffServClfrId and diffServClfrElementId that are not currently used
in the system's configuration. The values are validated when
creating diffServClfrId and diffServClfrElementId, and in the event
of a failure (which would happen if two managers simultaneously
attempted to create an entry) must be re-read.
3.2.2. diffServMultiFieldClfrTable - The Multi-field Classifier Table
This MIB defines a single parameter type for classification, the
Multi-field Classifier. As a parameter, a filter may be specified
once and applied to many interfaces, using
diffServClfrElementSpecific. This filter matches:
o IP source address prefix, including host, CIDR Prefix, and "any
source address"
o IP destination address prefix, including host, CIDR Prefix, and
"any destination address"
o IPv6 Flow ID
o IP protocol or "any"
o TCP/UDP/SCTP source port range, including "any"
o TCP/UDP/SCTP destination port range, including "any"
o Differentiated Services Code Point
Since port ranges, IP prefixes, or "any" are defined in each case, it
is clear that a wide variety of filters can be constructed. The
Differentiated Services Behavior Aggregate filter is a special case
of this filter, in which only the DSCP is specified.
Other MIB modules may define similar filters in the same way. For
example, a filter for Ethernet information might define source and
destination MAC addresses of "any", Ethernet Packet Type, IEEE 802.2
SAPs, and IEEE 802.1 priorities. A filter related to policy routing
might be structured like the diffServMultiFieldClfrTable, but contain
the BGP Communities of the source and destination prefix rather than
the prefix itself, meaning "any prefix in this community". For such
a filter, a table similar to diffServMultiFieldClfrTable is
constructed, and diffServClfrElementSpecific is configured to point
to it.
When the MIB is used for configuration,
diffServMultiFieldClfrNextFree always contains a legal value for
diffServMultiFieldClfrId that is not currently used in the system's
configuration.
3.3. Metering Traffic
As discussed in [MODEL], a meter and a shaper are functions that
operate on opposing ends of a link. A shaper schedules traffic for
transmission at specific times in order to approximate a particular
line speed or combination of line speeds. In its simplest form, if
the traffic stream contains constant sized packets, it might transmit
one packet per unit time to build the equivalent of a CBR circuit.
However, various factors intervene to make the approximation inexact;
multiple classes of traffic may occasionally schedule their traffic
at the same time, the variable length nature of IP traffic may
introduce variation, and factors in the link or physical layer may
change traffic timing. A meter integrates the arrival rate of
traffic and determines whether the shaper at the far end was
correctly applied, or whether the behavior of the application in
question is naturally close enough to such behavior to be acceptable
under a given policy.
A common type of meter is a Token Bucket meter, such as [srTCM] or
[trTCM]. This type of meter assumes the use of a shaper at a
previous node; applications which send at a constant rate when
sending may conform if the token bucket is properly specified. It
specifies the acceptable arrival rate and quantifies the acceptable
variability, often by specifying a burst size or an interval; since
rate = quantity/time, specifying any two of those parameters implies
the third, and a large interval provides for a forgiving system.
Multiple rates may be specified, as in AF, such that a subset of the
traffic (up to one rate) is accepted with one set of guarantees, and
traffic in excess of that but below another rate has a different set
of guarantees. Other types of meters exist as well.
One use of a meter is when a service provider sells at most, a
certain bit rate to one of its customers, and wants to drop the
excess. In such a case, the fractal nature of normal Internet
traffic must be reflected in large burst intervals, as TCP frequently
sends packet pairs or larger bursts, and responds poorly when more
than one packet in a round trip interval is dropped. Applications
like FTP contain the effect by simply staying below the target bit
rate; this type of configuration very adversely affects transaction
applications like HTTP, however. Another use of a meter is in the AF
specification, in which excess traffic is marked with a related DSCP
and subjected to slightly more active queue depth management. The
application is not sharply limited to a contracted rate in such a
case, but can be readily contained should its traffic create a
burden.
3.3.1. diffServMeterTable - The Meter Table
The Meter Table is a structural table, specifying a specific
functional data path element. Its entry consists essentially of
three RowPointers - a "succeed" pointer, for traffic conforming to
the meter, a "fail" pointer, for traffic not conforming to the meter,
and a "specific" pointer, to identify the parameters in question.
This structure is a bow to SNMP's limitations; it would be better to
have a structure with N rates and N+1 "next" pointers, with a single
algorithm specified. In this case, multiple meter entries connected
by the "fail" link are understood to contain the parameters for a
specified algorithm, and traffic conforming to a given rate follows
their "succeed" paths. Within this MIB, only Token Bucket parameters
are specified; other varieties of meters may be designed in other MIB
modules.
When the MIB is used for configuration, diffServMeterNextFree always
contains a legal value for diffServMeterId that is not currently used
in the system's configuration.
3.3.2. diffServTBParamTable - The Token Bucket Parameters Table
The Token Bucket Parameters Table is a set of parameters that define
a Token Bucket Meter. As a parameter, a token bucket may be
specified once and applied to many interfaces, using
diffServMeterSpecific. Specifically, several modes of [srTCM] and
[trTCM] are addressed. Other varieties of meters may be specified in
other MIB modules.
In general, if a Token Bucket has N rates, it has N+1 potential
outcomes - the traffic stream is slower than and therefore conforms
to all of the rates, it fails the first few but is slower than and
therefore conforms to the higher rates, or it fails all of them. As
such, multi-rate meters should specify those rates in monotonically
increasing order, passing through the diffServMeterFailNext from more
committed to more excess rates, and finally falling through
diffServMeterFailNext to the set of actions that apply to traffic
which conforms to none of the specified rates. diffServTBParamType
in the first entry indicates the algorithm being used. At each rate,
diffServTBParamRate is derivable from diffServTBParamBurstSize and
diffServTBParamInterval; a superior implementation will allow the
configuration of any two of diffServTBParamRate,
diffServTBParamBurstSize, and diffServTBParamInterval, and respond
with the appropriate error code if all three are specified but are
not mathematically related.
When the MIB is used for configuration, diffServTBParamNextFree
always contains a legal value for diffServTBParamId that is not
currently used in the system's configuration.
3.4. Actions applied to packets
"Actions" are the things a differentiated services interface PHB may
do to a packet in transit. At a minimum, such a policy might
calculate statistics on traffic in various configured classes, mark
it with a DSCP, drop it, or enqueue it before passing it on for other
processing.
Actions are composed of a structural element, the
diffServActionTable, and various component action entries that may be
applied. In the case of the Algorithmic Dropper, an additional
parameter table may be specified to control Active Queue Management,
as defined in [RED93] and other AQM specifications.
3.4.1. diffServActionTable - The Action Table
The action table identifies sequences of actions to be applied to a
packet. Successive actions are chained through diffServActionNext,
ultimately resulting in zeroDotZero (indicating that the policy is
complete), a pointer to a queue, or a pointer to some other
functional data path element.
When the MIB is used for configuration, diffServActionNextFree always
contains a legal value for diffServActionId that is not currently
used in the system's configuration.
3.4.2. diffServCountActTable - The Count Action Table
The count action accumulates statistics pertaining to traffic passing
through a given path through the policy. It is intended to be useful
for usage-based billing, for statistical studies, or for analysis of
the behavior of a policy in a given network. The objects in the
Count Action are various counters and a discontinuity time. The
counters display the number of packets and bytes encountered on the
path since the discontinuity time. They share the same discontinuity
time, which is the discontinuity time of the interface or agent.
The designers of this MIB expect that every path through a policy
should have a corresponding counter. In early versions, it was
impossible to configure an action without implementing a counter,
although the current design makes them in effect the network
manager's option, as a result of making actions consistent in
structure and extensibility. The assurance of proper debugging and
accounting is therefore left with the policy designer.
When the MIB is used for configuration, diffServCountActNextFree
always contains a legal value for diffServCountActId that is not
currently used in the system's configuration.
3.4.3. diffServDscpMarkActTable - The Mark Action Table
The Mark Action table is an unusual table, both in SNMP and in this
MIB. It might be viewed not so much as an array of single-object
entries as an array of OBJECT-IDENTIFIER conventions, as the OID for
a diffServDscpMarkActDscp instance conveys all of the necessary
information: packets are to be marked with the requisite DSCP.
As such, contrary to common practice, the index for the table is
read- only, and is both the Entry's index and its only value.
3.4.4. diffServAlgDropTable - The Algorithmic Drop Table
The Algorithmic Drop Table identifies a dropping algorithm, drops
packets, and counts the drops. Classified as an action, it is in
effect a method which applies a packet to a queue, and may modify
either. When the algorithm is "always drop", this is simple; when
the algorithm calls for head-drop, tail-drop, or a variety of Active
Queue Management, the queue is inspected, and in the case of Active
Queue Management, additional parameters are REQUIRED.
What may not be clear from the name is that an Algorithmic Drop
action often does not drop traffic. Algorithms other than "always
drop" normally drop a few percent of packets at most. The action
inspects the diffServQEntry that diffServAlgDropQMeasure points to in
order to determine whether the packet should be dropped.
When the MIB is used for configuration, diffServAlgDropNextFree
always contains a legal value for diffServAlgDropId that is not
currently used in the system's configuration.
3.4.5. diffServRandomDropTable - The Random Drop Parameters Table
The Random Drop Table is an extension of the Algorithmic Drop Table
intended for use on queues whose depth is actively managed. Active
Queue Management algorithms are typified by [RED93], but the
parameters they use vary. It was deemed for the purposes of this MIB
that the proper values to represent include:
o Target case mean queue depth, expressed in bytes or packets
o Worst case mean queue depth, expressed in bytes or packets
o Maximum drop rate expressed as drops per thousand
o Coefficient of an exponentially weighted moving average,
expressed as the numerator of a fraction whose denominator is
65536.
o Sampling rate
An example of the representation chosen in this MIB for this element
is shown in Figure 1.
Random droppers often have their drop probability function described
as a plot of drop probability (P) against averaged queue length (Q).
(Qmin,Pmin) then defines the start of the characteristic plot.
Normally Pmin=0, meaning with average queue length below Qmin, there
will be no drops. (Qmax,Pmax) defines a "knee" on the plot, after
which point the drop probability becomes more progressive (greater
slope). (Qclip,1) defines the queue length at which all packets will
be dropped. Notice this is different from Tail Drop because this
uses an averaged queue length, although it is possible for Qclip to
equal Qmax.
In the MIB module, diffServRandomDropMinThreshBytes and
diffServRandomDropMinThreshPkts represent Qmin.
diffServRandomDropMaxThreshBytes and diffServRandomDropMaxThreshPkts
represent Qmax. diffServAlgDropQThreshold represents Qclip.
diffServRandomDropInvProbMax represents Pmax (inverse). This MIB
does not represent Pmin (assumed to be zero unless otherwise
represented). In addition, since message memory is finite, queues
generally have some upper bound above which they are incapable of
storing additional traffic. Normally this number is equal to Qclip,
specified by diffServAlgDropQThreshold.
AlgDrop Queue
+-----------------+ +-------+
--->| Next ---------+--+------------------->| Next -+--> ...
| QMeasure -------+--+ | ... |
| QThreshold | RandomDrop +-------+
| Type=randomDrop | +----------------+
| Specific -------+---->| MinThreshBytes |
+-----------------+ | MaxThreshBytes |
| ProbMax |
| Weight |
| SamplingRate |
+----------------+
Figure 1: Example Use of the RandomDropTable for Random Droppers
Each random dropper specification is associated with a queue. This
allows multiple drop processes (of same or different types) to be
associated with the same queue, as different PHB implementations may
require. This also allows for sequences of multiple droppers if
necessary.
The calculation of a smoothed queue length may also have an important
bearing on the behavior of the dropper: parameters may include the
sampling interval or rate, and the weight of each sample. The
performance may be very sensitive to the values of these parameters
and a wide range of possible values may be required due to a wide
range of link speeds. Most algorithms include a sample weight,
represented here by diffServRandomDropWeight. The availability of
diffServRandomDropSamplingRate as readable is important, the
information provided by Sampling Rate is essential to the
configuration of diffServRandomDropWeight. Having Sampling Rate be
configurable is also helpful, as line speed increases, the ability to
have queue sampling be less frequent than packet arrival is needed.
Note, however, that there is ongoing research on this topic, see e.g.
[ACTQMGMT] and [AQMROUTER].
Additional parameters may be added in an enterprise MIB module, e.g.
by using AUGMENTS on this table, to handle aspects of random drop
algorithms that are not standardized here.
When the MIB is used for configuration, diffServRandomDropNextFree
always contains a legal value for diffServRandomDropId that is not
currently used in the system's configuration.
3.5. Queuing and Scheduling of Packets
These include Queues and Schedulers, which are inter-related in their
use of queuing techniques. By doing so, it is possible to build
multi-level schedulers, such as those which treat a set of queues as
having priority among them, and at a specific priority find a
secondary WFQ scheduler with some number of queues.
3.5.1. diffServQTable - The Class or Queue Table
The Queue Table models simple FIFO queues. The Scheduler Table
allows flexibility in constructing both simple and somewhat more
complex queuing hierarchies from those queues.
Queue Table entries are pointed at by the "next" attributes of the
upstream elements, such as diffServMeterSucceedNext or
diffServActionNext. Note that multiple upstream elements may direct
their traffic to the same Queue Table entry. For example, the
Assured Forwarding PHB suggests that all traffic marked AF11, AF12 or
AF13 be placed in the same queue, after metering, without reordering.
To accomplish that, the upstream diffServAlgDropNext pointers each
point to the same diffServQEntry.
A common requirement of a queue is that its traffic enjoy a certain
minimum or maximum rate, or that it be given a certain priority.
Functionally, the selection of such is a function of a scheduler.
The parameter is associated with the queue, however, using the
Minimum or Maximum Rate Parameters Table.
When the MIB is used for configuration, diffServQNextFree always
contains a legal value for diffServQId that is not currently used in
the system's configuration.
3.5.2. diffServSchedulerTable - The Scheduler Table
The scheduler, and therefore the Scheduler Table, accepts inputs from
either queues or a preceding scheduler. The Scheduler Table allows
flexibility in constructing both simple and somewhat more complex
queuing hierarchies from those queues.
When the MIB is used for configuration, diffServSchedulerNextFree
always contains a legal value for diffServSchedulerId that is not
currently used in the system's configuration.
3.5.3. diffServMinRateTable - The Minimum Rate Table
When the output rate of a queue or scheduler must be given a minimum
rate or a priority, this is done using the diffServMinRateTable.
Rates may be expressed as absolute rates, or as a fraction of
ifSpeed, and imply the use of a rate-based scheduler such as WFQ or
WRR. The use of a priority implies the use of a Priority Scheduler.
Only one of the Absolute or Relative rates needs to be set; the other
takes the relevant value as a result. Excess capacity is distributed
proportionally among the inputs to a scheduler using the assured
rate. More complex functionality may be described by augmenting this
MIB.
When a priority scheduler is used, its effect is to give the queue
the entire capacity of the subject interface less the capacity used
by higher priorities, if there is traffic present to use it. This is
true regardless of the rate specifications applied to that queue or
other queues on the interface. Policing excess traffic will mitigate
this behavior.
When the MIB is used for configuration, diffServMinRateNextFree
always contains a legal value for diffServMinRateId that is not
currently used in the system's configuration.
3.5.4. diffServMaxRateTable - The Maximum Rate Table
When the output rate of a queue or scheduler must be limited to at
most a specified maximum rate, this is done using the
diffServMaxRateTable. Rates may be expressed as absolute rates, or
as a fraction of ifSpeed. Only one of the Absolute or Relative rate
needs to be set; the other takes the relevant value as a result.
The definition of a multirate shaper requires multiple
diffServMaxRateEntries. In this case, an algorithm such as [SHAPER]
is used. In that algorithm, more than one rate is specified, and at
any given time traffic is shaped to the lowest specified rate which
exceeds the arrival rate of traffic.
When the MIB is used for configuration, diffServMaxRateNextFree
always contains a legal value for diffServMaxRateId that is not
currently used in the system's configuration.
3.5.5. Using queues and schedulers together
For representing a Strict Priority scheduler, each scheduler input is
assigned a priority with respect to all the other inputs feeding the
same scheduler, with default values for the other parameters.
Higher-priority traffic that is not being delayed for shaping will be
serviced before a lower-priority input. An example is found in
Figure 2.
For weighted scheduling methods, such as WFQ or WRR, the "weight" of
a given scheduler input is represented with a Minimum Service Rate
leaky-bucket profile which provides a guaranteed minimum bandwidth to
that input, if required. This is represented by a rate
diffServMinRateAbsolute; the classical weight is the ratio between
that rate and the interface speed, or perhaps the ratio between that
rate and the sum of the configured rates for classes. The rate may
be represented by a relative value, as a fraction of the interface's
current line rate, diffServMinRateRelative, to assist in cases where
line rates are variable or where a higher-level policy might be
expressed in terms of fractions of network resources. The two rate
parameters are inter-related and changes in one may be reflected in
the other. An example is found in figure 3.
+-----+
+-------+ | P S |
| Queue +------------>+ r c |
+-------+-+--------+ | i h |
|Priority| | o e |
+--------+ | r d +----------->
+-------+ | i u |
| Queue +------------>+ t l |
+-------+-+--------+ | y e |
|Priority| | r |
+--------+ +-----+
Figure 2: Priority Scheduler with two queues
For weighted scheduling methods, one can say loosely, that WRR
focuses on meeting bandwidth sharing, without concern for relative
delay amongst the queues; where WFQ controls both queue the service
order and the amount of traffic serviced, providing bandwidth sharing
and relative delay ordering amongst the queues.
A queue or scheduled set of queues (which is an input to a scheduler)
may also be capable of acting as a non-work-conserving [MODEL]
traffic shaper: this is done by defining a Maximum Service Rate
leaky-bucket profile in order to limit the scheduler bandwidth
available to that input. This is represented by a rate, in
diffServMaxRateAbsolute; the classical weight is the ratio between
that rate and the interface speed, or perhaps the ratio between that
rate and the sum of the configured rates for classes. The rate may
be represented by a relative value, as a fraction of the interface's
current line rate, diffServMaxRateRelative. This MIB presumes that
shaping is something a scheduler does to its inputs, which it models
as a queue with a maximum rate or a scheduler whose output has a
maximum rate.
+-----+
+-------+ | W S |
| Queue +------------>+ R c |
+-------+-+--------+ | R h |
| Rate | | e |
+--------+ | o d +----------->
+-------+ | r u |
| Queue +------------>+ l |
+-------+-+--------+ | W e |
| Rate | | F r |
+--------+ | Q |
+-----+
Figure 3: WRR or WFQ rate-based scheduler with two inputs
The same may be done on a queue, if a given class is to be shaped to
a maximum rate without shaping other classes, as in Figure 5.
Other types of priority and weighted scheduling methods can be
defined using existing parameters in diffServMinRateEntry. NOTE:
diffServSchedulerMethod uses OBJECT IDENTIFIER syntax, with the
different types of scheduling methods defined as OBJECT-IDENTITY.
+---+
+-------+ | S |
| Queue +------------>+ c |
+-------+-+--------+ | h |
| | | e +----------->
+--------+ | d +-+-------+
| u | |Shaping|
+-------+ | l | | Rate |
| Queue +------------>+ e | +-------+
+-------+-+--------+ | r |
| | +---+
+--------+
Figure 4: Shaping scheduled traffic to a known rate
+---+
+-------+ | S |
| Queue +------------>+ c |
+-------+-+--------+ | h |
|Min Rate| | e +----------->
+--------+ | d |
| u |
+-------+ | l |
| Queue +------------>+ e |
+-------+-+--------+ | r |
|Min Rate| | |
+--------+ | |
|Max Rate| | |
+--------+ +---+
Figure 5: Shaping one input to a work-conserving scheduler
Future scheduling methods may be defined in other MIBs. This
requires an OBJECT-IDENTITY definition, a description of how the
existing objects are reused, if they are, and any new objects they
require.
To implement an EF and two AF classes, one must use a combination of
priority and WRR/WFQ scheduling. This requires us to cascade two
schedulers. If one were to additionally shape the output of the
system to a rate lower than the interface rate, one must place an
upper bound rate on the output of the priority scheduler. See figure
6.
3.6. Example configuration for AF and EF
For the sake of argument, let us build an example with one EF class
and four AF classes using the constructs in this MIB.
3.6.1. AF and EF Ingress Interface Configuration
The ingress edge interface identifies traffic into classes, meters
it, and ensures that any excess is appropriately dealt with according
to the PHB. For AF, this means marking excess; for EF, it means
dropping excess or shaping it to a maximum rate.
+-----+
+-------+ | P S |
| Queue +---------------------------------->+ r c |
+-------+----------------------+--------+ | i h |
|Priority| | o e +----------->
+--------+ | r d +-+-------+
+------+ | i u | |Shaping|
+-------+ | W S +------------->+ t l | | Rate |
| Queue +------------>+ R c +-+--------+ | y e | +-------+
+-------+-+--------+ | R h | |Priority| | r |
|Min Rate| | e | +--------+ +-----+
+--------+ | o d |
+-------+ | r u |
| Queue +------------>+ l |
+-------+-+--------+ | W e |
|Min Rate| | F r |
+--------+ | Q |
+------+
Figure 6: Combined EF and AF services using cascaded schedulers.
+-----------------------+
| diffServDataPathStart |
+-----------+-----------+
|
+----------+
|
+--+--+ +-----+ +-----+ +-----+ +-----+
| AF1 +-----+ AF2 +-----+ AF3 +-----+ AF4 +-----+ EF |
+--+--+ +--+--+ +--+--+ +--+--+ +--+--+
| | | | |
+--+--+ +--+--+ +--+--+ +--+--+ +--+--+
|trTCM| |trTCM| |trTCM| |trTCM| |srTCM|
|Meter| |Meter| |Meter| |Meter| |Meter|
+-+++-+ +-+++-+ +-+++-+ +-+++-+ +-+-+-+
||| ||| ||| ||| | |
+-+||---+ +-+||---+ +-+||---+ +-+||---+ +-+-|---+
|+-+|----+ |+-+|----+ |+-+|----+ |+-+|----+ |+--+----+
||+-+-----+ ||+-+-----+ ||+-+-----+ ||+-+-----+ ||Actions|
+||Actions| +||Actions| +||Actions| +||Actions| +| |
+| | +| | +| | +| | +-+-----+
+-+-----+ +-+-----+ +-+-----+ +-+-----+ |
||| ||| ||| ||| |
VVV VVV VVV VVV V
Accepted traffic is sent to IP forwarding
Figure 7: combined EF and AF implementation, ingress side
3.6.1.1. Classification In The Example
A packet arriving at an ingress interface picks up its policy from
the diffServDataPathTable. This points to a classifier, which will
select traffic according to some specification for each traffic
class.
An example of a classifier for an AFm class would be a set of three
classifier elements, each pointing to a Multi-field classification
parameter block identifying one of the AFmn DSCPs. Alternatively,
the filters might contain selectors for HTTP traffic or some other
application.
An example of a classifier for EF traffic might be a classifier
element pointing to a filter specifying the EF code point, a
collection of classifiers with parameter blocks specifying individual
telephone calls, or a variety of other approaches.
Typically, of course, a classifier identifies a variety of traffic
and breaks it up into separate classes. It might very well contain
fourteen classifier elements indicating the twelve AFmn DSCP values,
EF, and "everything else". These would presumably direct traffic
down six functional data paths: one for each AF or EF class, and one
for all other traffic.
3.6.1.2. AF Implementation On an Ingress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. These groups of traffic conform to both specified
rates, only the higher one, or none. The intent, on the ingress
interface at the edge of the network, is to measure and appropriately
mark traffic.
3.6.1.2.1. AF Metering On an Ingress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. If two rates R and S, where R < S, are specified
and traffic arrives at rate T, traffic comprising up to R bits per
second is considered to conform to the "confirmed" rate, R. If
R < T, traffic comprising up to S-R bits per second is considered to
conform to the "excess" rate, S. Any further excess is non-
conformant.
Two meter entries are used to configure this, one for the conforming
rate and one for the excess rate. The rate parameters are stored in
associated Token Bucket Parameter Entries. The "FailNext" pointer of
the lower rate Meter Entry points to the other Meter Entry; both
"SucceedNext" pointers and the "FailNext" pointer of the higher Meter
Entry point to lists of actions. In the color-blind mode, all three
classifier "next" entries point to the lower rate meter entry. In
the color-aware mode, the AFm1 classifier points to the lower rate
entry, the AFm2 classifier points to the higher rate entry (as it is
only compared against that rate), and the AFm3 classifier points
directly to the actions taken when both rates fail.
3.6.1.2.2. AF Actions On an Ingress Edge Interface
For network planning and perhaps for billing purposes, arriving
traffic is normally counted. Therefore, a "count" action, consisting
of an action table entry pointing to a count table entry, is
configured.
Also, traffic is marked with the appropriate DSCP. The first R bits
per second are marked AFm1, the next S-R bits per second are marked
AFm2, and the rest is marked AFm3. It may be that traffic is
arriving marked with the same DSCP, but in general, the additional
complexity of deciding that it is being remarked to the same value is
not useful. Therefore, a "mark" action, consisting of an action
table entry pointing to a mark table entry, is configured.
At this point, the usual case is that traffic is now forwarded in the
usual manner. To indicate this, the "SucceedNext" pointer of the
Mark Action is set to zeroDotZero.
3.6.1.3. EF Implementation On an Ingress Edge Interface
The EF class applies a Single Rate Two Color Meter, dividing traffic
into "conforming" and "excess" groups. The intent, on the ingress
interface at the edge of the network, is to measure and appropriately
mark conforming traffic and drop the excess.
3.6.1.3.1. EF Metering On an Ingress Edge Interface
A single rate two color (srTCM) meter requires one token bucket. It
is therefore configured using a single meter entry with a
corresponding Token Bucket Parameter Entry. Arriving traffic either
"succeeds" or "fails".
3.6.1.3.2. EF Actions On an Ingress Edge Interface
For network planning and perhaps for billing purposes, arriving
traffic that conforms to the meter is normally counted. Therefore, a
"count" action, consisting of an action table entry pointing to a
count table entry, is configured.
Also, traffic is (re)marked with the EF DSCP. Therefore, a "mark"
action, consisting of an action table entry pointing to a mark table
entry, is configured.
At this point, the successful traffic is now forwarded in the usual
manner. To indicate this, the "SucceedNext" pointer of the Mark
Action is set to zeroDotZero.
Traffic that exceeded the arrival policy, however, is to be dropped.
One can use a count action on this traffic if the several counters
are interesting. However, since the drop counter in the Algorithmic
Drop Entry will count packets dropped, this is not clearly necessary.
An Algorithmic Drop Entry of the type "alwaysDrop" with no successor
is sufficient.
3.7. AF and EF Egress Edge Interface Configuration
3.7.1. Classification On an Egress Edge Interface
A packet arriving at an egress interface may have been classified on
an ingress interface, and the egress interface may have access to
that information. If it is relevant, there is no reason not to use
that information. If it is not available, however, there may be a
need to (re)classify on the egress interface. In any event, it picks
up its "program" from the diffServDataPathTable. This points to a
classifier, which will select traffic according to some specification
for each traffic class.
+-----------------------+
| diffServDataPathStart |
+-----------+-----------+
|
+----------+
|
+--+--+ +-----+ +-----+ +-----+ +-----+
| AF1 +-----+ AF2 +-----+ AF3 +-----+ AF4 +-----+ EF |
+-+++-+ +-+++-+ +-+++-+ +-+++-+ +-+-+-+
||| ||| ||| ||| | |
+-+++-+ +-+++-+ +-+++-+ +-+++-+ +-+-+-+
|trTCM| |trTCM| |trTCM| |trTCM| |srTCM|
|Meter| |Meter| |Meter| |Meter| |Meter|
+-+++-+ +-+++-+ +-+++-+ +-+++-+ +-+-+-+
||| ||| ||| ||| | |
+-+||---+ +-+||---+ +-+||---+ +-+||---+ +-+-|---+
|+-+|----+ |+-+|----+ |+-+|----+ |+-+|----+ |+--+----+
||+-+-----+ ||+-+-----+ ||+-+-----+ ||+-+-----+ ||Actions|
+||Actions| +||Actions| +||Actions| +||Actions| +| |
+| | +| | +| | +| | +-+-----+
+-+-----+ +-+-----+ +-+-----+ +-+-----+ |
||| ||| ||| ||| |
+-+++--+ +-+++--+ +-+++--+ +-+++--+ +--+---+
| Queue| | Queue| | Queue| | Queue| | Queue|
+--+---+ +--+---+ +--+---+ +--+---+ +--+---+
| | | | |
+--+-----------+-----------+-----------+---+ |
| WFQ/WRR Scheduler | |
+--------------------------------------+---+ |
| |
+-----+-----------+----+
| Priority Scheduler |
+----------+-----------+
|
V
Figure 8: combined EF and AF implementation
An example of a classifier for an AFm class would be a succession of
three classifier elements, each pointing to a Multi-field
classification parameter block identifying one of the AFmn DSCPs.
Alternatively, the filter might contain selectors for HTTP traffic or
some other application.
An example of a classifier for EF traffic might be either a
classifier element pointing to a Multi-field parameter specifying the
EF code point, or a collection of classifiers with parameter blocks
specifying individual telephone calls, or a variety of other
approaches.
Each classifier delivers traffic to appropriate functional data path
elements.
3.7.2. AF Implementation On an Egress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. These groups of traffic conform to both specified
rates, only the higher one, or none. The intent, on the ingress
interface at the edge of the network, is to measure and appropriately
mark traffic.
3.7.2.1. AF Metering On an Egress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. If two rates R and S, where R < S, are specified
and traffic arrives at rate T, traffic comprising up to R bits per
second is considered to conform to the "confirmed" rate, R. If
R < T, traffic comprising up to S-R bits per second is considered to
conform to the "excess" rate, S. Any further excess is non-
conformant.
Two meter entries are used to configure this, one for the conforming
rate and one for the excess rate. The rate parameters are stored in
associated Token Bucket Parameter Entries. The "FailNext" pointer of
the lower rate Meter Entry points to the other Meter Entry; both
"SucceedNext" pointers and the "FailNext" pointer of the higher Meter
Entry point to lists of actions. In the color-blind mode, all three
classifier "next" entries point to the lower rate meter entry. In
the color-aware mode, the AFm1 classifier points to the lower rate
entry, the AFm2 classifier points to the higher rate entry (as it is
only compared against that rate), and the AFm3 classifier points
directly to the actions taken when both rates fail.
+-----------------------------------------------------+
| Classifier |
+--------+--------------------------------------------+
|Green| Yellow| Red
| | |
+--+-----+-------+--+ Fail +--------------------+
| Meter +------+ Meter |
+--+----------------+ +---+-------+--------+
| Succeed (Green) | |Fail (Red)
| +---------+ |
| | Succeed (Yellow)|
+----+----+ +----+----+ +----+----+
| Count | | Count | | Count |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
|Mark AFx1| |Mark AFx2| |Mark AFx3|
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
| Random | | Random | | Random |
| Drop | | Drop | | Drop |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+--------+-----------------+-----------------+--------+
| Queue |
+--------------------------+--------------------------+
|
+----+----+
| Rate |
|Scheduler|
+----+----+
|
Figure 9a: Typical AF Edge egress interface configuration,
using color-blind meters
+-----------------------------------------------------+
| Classifier |
+--------+--------------------------------------------+
|Green | Yellow | Red
| | |
+----+----+ +----+----+ |
| Count | | Count | |
| Action +-------+ Action +------------+
+----+----+ Fail +----+----+ Fail |
|Succeed |Succeed |
+----+----+ +----+----+ +----+----+
| Count | | Count | | Count |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
|Mark AFx1| |Mark AFx2| |Mark AFx3|
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
| Random | | Random | | Random |
| Drop | | Drop | | Drop |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+--------+-----------------+-----------------+--------+
| Queue |
+--------------------------+--------------------------+
|
+----+----+
| Rate |
|Scheduler|
+----+----+
|
Figure 9b: Typical AF Edge egress interface configuration,
using color-aware meters
+-----------------------------------------------------+
| Classifier |
+--------+-----------------+-----------------+--------+
| Green | Yellow | Red
| | |
+----+----+ +----+----+ +----+----+
| Count | | Count | | Count |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
| Random | | Random | | Random |
| Drop | | Drop | | Drop |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+--------+-----------------+-----------------+--------+
| Queue |
+--------------------------+--------------------------+
|
+----+----+
| Rate |
|Scheduler|
+----+----+
|
Figure 10: Typical AF Edge core interface configuration
3.7.2.2. AF Actions On an Egress Edge Interface
For network planning and perhaps for billing purposes, departing
traffic is normally counted. Therefore, a "count" action, consisting
of an action table entry pointing to a count table entry, is
configured.
Also, traffic may be marked with an appropriate DSCP. The first R
bits per second are marked AFm1, the next S-R bits per second are
marked AFm2, and the rest is marked AFm3. It may be that traffic is
arriving marked with the same DSCP, but in general, the additional
complexity of deciding that it is being remarked to the same value is
not useful. Therefore, a "mark" action, consisting of an action
table entry pointing to a mark table entry, is configured.
At this point, the usual case is that traffic is now queued for
transmission. The queue uses Active Queue Management, using an
algorithm such as RED. Therefore, an Algorithmic Dropper is
configured for each AFmn traffic stream, with a slightly lower min-
threshold (and possibly lower max-threshold) for the excess traffic
than for the committed traffic.
3.7.2.3. AF Rate-based Queuing On an Egress Edge Interface
The queue expected by AF is normally a work-conserving queue. It
usually has a specified minimum rate, and may have a maximum rate
below the bandwidth of the interface. In concept, it will use as
much bandwidth as is available to it, but assure the lower bound.
Common ways to implement this include various forms of Weighted Fair
Queuing (WFQ) or Weighted Round Robin (WRR). Integrated over a
longer interval, these give each class a predictable throughput rate.
They differ in that over short intervals they will order traffic
differently. In general, traffic classes that keep traffic in queue
will tend to absorb latency from queues with lower mean occupancy, in
exchange for which they make use of any available capacity.
3.7.3. EF Implementation On an Egress Edge Interface
The EF class applies a Single Rate Two Color Meter, dividing traffic
into "conforming" and "excess" groups. The intent, on the egress
interface at the edge of the network, is to measure and appropriately
mark conforming traffic and drop the excess.
3.7.3.1. EF Metering On an Egress Edge Interface
A single rate two color (srTCM) meter requires one token bucket. It
is therefore configured using a single meter entry with a
corresponding Token Bucket Parameter Entry. Arriving traffic either
"succeeds" or "fails".
3.7.3.2. EF Actions On an Egress Edge Interface
For network planning and perhaps for billing purposes, departing
traffic that conforms to the meter is normally counted. Therefore, a
"count" action, consisting of an action table entry pointing to a
count table entry, is configured.
Also, traffic is (re)marked with the EF DSCP. Therefore, a "mark"
action, consisting of an action table entry pointing to a mark table
entry, is configured.
+-----------------------------------------------------+
| Classifier |
+-------------------------+---------------------------+
| Voice
|
+-------------+----------+
| Meter |
+----+-------------+-----+
| Succeed | Fail
| |
+----+----+ +----+----+
| Count | | Always |
| Action | | Drop |
+----+----+ | Action |
| +---------+
+----+---------+
| Algorithmic |
| Drop Action |
+----+---------+
|
+----------------+---------------+
| Queue |
+----------------+---------------+
|
+-----+-----+
| Priority |
| Scheduler |
+-----+-----+
Figure 11: Typical EF Edge (Policing) Configuration
+--------------------------------+
| Classifier |
+----------------+---------------+
| Voice
|
+----+----+
| Count |
| Action |
+----+----+
|
+------+-------+
| Algorithmic |
| Drop Action |
+------+-------+
|
+----------------+---------------+
| Queue |
+----------------+---------------+
|
+-----+-----+
| Priority |
| Scheduler |
+-----+-----+
Figure 12: Typical EF Core interface Configuration
At this point, the successful traffic is now queued for transmission,
using a priority queue or perhaps a rate-based queue with significant
over-provision. Since the amount of traffic present is known, one
might not drop from this queue at all.
Traffic that exceeded the policy, however, is dropped. A count
action can be used on this traffic if the several counters are
interesting. However, since the drop counter in the Algorithmic Drop
Entry will count packets dropped, this is not clearly necessary. An
Algorithmic Drop Entry of the type "alwaysDrop" with no successor is
sufficient.
3.7.3.3. EF Priority Queuing On an Egress Edge Interface
The normal implementation is a priority queue, to minimize induced
jitter. A separate queue is used for each EF class, with a strict
ordering.
4. Conventions used in this MIB
4.1. The use of RowPointer to indicate data path linkage
RowPointer is a textual convention used to identify a conceptual row
in a MIB Table by pointing to one of its objects. One of the ways
this MIB uses it is to indicate succession, pointing to data path
linkage table entries.
For succession, it answers the question "what happens next?". Rather
than presume that the next table must be as specified in the
conceptual model [MODEL] and providing its index, the RowPointer
takes you to the MIB row representing that thing. In the
diffServMeterTable, for example, the diffServMeterFailNext RowPointer
might take you to another meter, while the diffServMeterSucceedNext
RowPointer would take you to an action.
Since a RowPointer is not tied to any specific object except by the
value it contains, it is possible and acceptable to use RowPointers
to merge data paths. An obvious example of such a use is in the
classifier: traffic matching the DSCPs AF11, AF12, and AF13 might be
presented to the same meter in order to perform the processing
described in the Assured Forwarding PHB. Another use would be to
merge data paths from several interfaces; if they represent a single
service contract, having them share a common set of counters and
common policy may be a desirable configuration. Note well, however,
that such configurations may have related implementation issues - if
Differentiated Services processing for the interfaces is implemented
in multiple forwarding engines, the engines will need to communicate
if they are to implement such a feature. An implementation that
fails to provide this capability is not considered to have failed the
intention of this MIB or of the [MODEL]; an implementation that does
provide it is not considered superior from a standards perspective.
NOTE -- the RowPointer construct is used to connect the functional
data paths. The [MODEL] describes these as TCBs, as an aid to
understanding. This MIB, however, does not model TCBs directly.
It operates at a lower level of abstraction using only individual
elements, connected in succession by RowPointers. Therefore, the
concept of TCBs enclosing individual Functional Data Path elements
is not directly applicable to this MIB, although management tools
that use this MIB may employ such a concept.
It is possible that a path through a device following a set of
RowPointers is indeterminate i.e. it ends in a dangling RowPointer.
Guidance is provided in the MIB module's DESCRIPTION-clause for each
of the linkage attribute. In general, for both zeroDotZero and
dangling RowPointer, it is assumed the data path ends and the traffic
should be given to the next logical part of the device, usually a
forwarding process or a transmission engine, or the proverbial bit-
bucket. Any variation from this usage is indicated by the attribute
affected.
4.2. The use of RowPointer to indicate parameters
RowPointer is also used in this MIB to indicate parameterization, for
pointing to parameterization table entries.
For indirection (as in the diffServClfrElementTable), the idea is to
allow other MIBs, including proprietary ones, to define new and
arcane filters - MAC headers, IPv4 and IPv6 headers, BGP Communities
and all sorts of other things - while still utilizing the structures
of this MIB. This is a form of class inheritance (in "object
oriented" language): it allows base object definitions ("classes") to
be extended in proprietary or standard ways, in the future, by other
documents.
RowPointer also clearly indicates the identified conceptual row's
content does not change, hence they can be simultaneously used and
pointed to, by more than one data path linkage table entries. The
identification of RowPointer allows higher level policy mechanisms to
take advantage of this characteristic.
4.3. Conceptual row creation and deletion
A number of conceptual tables defined in this MIB use as an index an
arbitrary integer value, unique across the scope of the agent. In
order to help with multi-manager row-creation problems, a mechanism
must be provided to allow a manager to obtain unique values for such
an index and to ensure that, when used, the manager knows whether it
got what it wanted or not.
Typically, such a table has an associated NextFree variable e.g.
diffServClfrNextFree which provides a suitable value for the index of
the next row to be created e.g. diffServClfrId. The value zero is
used to indicate that the agent can configure no more entries. The
table also has a columnar Status attribute with RowStatus syntax [RFC
2579].
Generally, if a manager attempts to create a row, the agent will
create the row and return success. If the agent has insufficient
resources or such a row already exists, then it returns an error. A
manager must be prepared to try again in such circumstances, probably
by re-reading the NextFree to obtain a new index value in case a
second manager had got in between the first manager's read of the
NextFree value and the first manager's row-creation attempt.
To simplify management creation and deletion of rows in this MIB, the
agent is expected to assist in maintaining its consistency. It may
accomplish this by maintaining internal usage counters for any row
that might be pointed to by a RowPointer, or by any equivalent means.
When a RowPointer is created or written, and the row it points to
does not exist, the SET returns an inconsistentValue error. When a
RowStatus variable is set to 'destroy' but the usage counter is non-
zero, the SET returns no error but the indicated row is left intact.
The agent should later remove the row in the event that the usage
counter becomes zero.
The use of RowStatus is covered in more detail in [RFC 2579].
5. Extending this MIB
With the structures of this MIB divided into data path linkage tables
and parameterization tables, and with the use of RowPointer, new data
path linkage and parameterization tables can be defined in other MIB
modules, and used with tables defined in this MIB. This MIB does not
limit the type of entries its RowPointer attributes can point to,
hence new functional data path elements can be defined in other MIBs
and integrated with functional data path elements of this MIB. For
example, new Action functional data path element can be defined for
Traffic Engineering and be integrated with Differentiated Services
functional data path elements, possibly used within the same data
path sharing the same classifiers and meters.
It is more likely that new parameterization tables will be created in
other MIBs as new methods or proprietary methods get deployed for
existing Differentiated Services Functional Data Path Elements. For
example, different kinds of filters can be defined by using new
filter parameterization tables. New scheduling methods can be
deployed by defining new scheduling method OIDs and new scheduling
parameter tables.
Notice both new data path linkage tables and parameterization tables
can be added without needing to change this MIB document or affect
existing tables and their usage.
6. MIB Definition
DIFFSERV-DSCP-TC DEFINITIONS ::= BEGIN
IMPORTS
Integer32, MODULE-IDENTITY, mib-2
FROM SNMPv2-SMI
TEXTUAL-CONVENTION
FROM SNMPv2-TC;
diffServDSCPTC MODULE-IDENTITY
LAST-UPDATED "200205090000Z"
ORGANIZATION "IETF Differentiated Services WG"
CONTACT-INFO
" Fred Baker
Cisco Systems
1121 Via Del Rey
Santa Barbara, CA 93117, USA
E-mail: fred@cisco.com
Kwok Ho Chan
Nortel Networks
600 Technology Park Drive
Billerica, MA 01821, USA
E-mail: khchan@nortelnetworks.com
Andrew Smith
Harbour Networks
Jiuling Building
21 North Xisanhuan Ave.
Beijing, 100089, PRC
E-mail: ah_smith@acm.org
Differentiated Services Working Group:
diffserv@ietf.org"
DESCRIPTION
"The Textual Conventions defined in this module should be used
whenever a Differentiated Services Code Point is used in a MIB."
REVISION "200205090000Z"
DESCRIPTION
"Initial version, published as RFC 3289."
::= { mib-2 96 }
Dscp ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"A Differentiated Services Code-Point that may be used for
marking a traffic stream."
REFERENCE
"RFC 2474, RFC 2780"
SYNTAX Integer32 (0..63)
DscpOrAny ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"The IP header Differentiated Services Code-Point that may be
used for discriminating among traffic streams. The value -1 is
used to indicate a wild card i.e. any value."
REFERENCE
"RFC 2474, RFC 2780"
SYNTAX Integer32 (-1 | 0..63)
END
DIFFSERV-MIB DEFINITIONS ::= BEGIN
IMPORTS
Unsigned32, Counter64, MODULE-IDENTITY, OBJECT-TYPE,
OBJECT-IDENTITY, zeroDotZero, mib-2
FROM SNMPv2-SMI
TEXTUAL-CONVENTION, RowStatus, RowPointer,
StorageType, AutonomousType
FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP
FROM SNMPv2-CONF
ifIndex, InterfaceIndexOrZero
FROM IF-MIB
InetAddressType, InetAddress, InetAddressPrefixLength,
InetPortNumber
FROM INET-ADDRESS-MIB
BurstSize
FROM INTEGRATED-SERVICES-MIB
Dscp, DscpOrAny
FROM DIFFSERV-DSCP-TC;
diffServMib MODULE-IDENTITY
LAST-UPDATED "200202070000Z"
ORGANIZATION "IETF Differentiated Services WG"
CONTACT-INFO
" Fred Baker
Cisco Systems
1121 Via Del Rey
Santa Barbara, CA 93117, USA
E-mail: fred@cisco.com
Kwok Ho Chan
Nortel Networks
600 Technology Park Drive
Billerica, MA 01821, USA
E-mail: khchan@nortelnetworks.com
Andrew Smith
Harbour Networks
Jiuling Building
21 North Xisanhuan Ave.
Beijing, 100089, PRC
E-mail: ah_smith@acm.org
Differentiated Services Working Group:
diffserv@ietf.org"
DESCRIPTION
"This MIB defines the objects necessary to manage a device that
uses the Differentiated Services Architecture described in RFC
2475. The Conceptual Model of a Differentiated Services Router
provides supporting information on how such a router is modeled."
REVISION "200202070000Z"
DESCRIPTION
"Initial version, published as RFC 3289."
::= { mib-2 97 }
diffServMIBObjects OBJECT IDENTIFIER ::= { diffServMib 1 }
diffServMIBConformance OBJECT IDENTIFIER ::= { diffServMib 2 }
diffServMIBAdmin OBJECT IDENTIFIER ::= { diffServMib 3 }
IndexInteger ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"An integer which may be used as a table index."
SYNTAX Unsigned32 (1..4294967295)
IndexIntegerNextFree ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"An integer which may be used as a new Index in a table.
The special value of 0 indicates that no more new entries can be
created in the relevant table.
When a MIB is used for configuration, an object with this SYNTAX
always contains a legal value (if non-zero) for an index that is
not currently used in the relevant table. The Command Generator
(Network Management Application) reads this variable and uses the
(non-zero) value read when creating a new row with an SNMP SET.
When the SET is performed, the Command Responder (agent) must
determine whether the value is indeed still unused; Two Network
Management Applications may attempt to create a row
(configuration entry) simultaneously and use the same value. If
it is currently unused, the SET succeeds and the Command
Responder (agent) changes the value of this object, according to
an implementation-specific algorithm. If the value is in use,
however, the SET fails. The Network Management Application must
then re-read this variable to obtain a new usable value.
An OBJECT-TYPE definition using this SYNTAX MUST specify the
relevant table for which the object is providing this
functionality."
SYNTAX Unsigned32 (0..4294967295)
IfDirection ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"IfDirection specifies a direction of data travel on an
interface. 'inbound' traffic is operated on during reception from
the interface, while 'outbound' traffic is operated on prior to
transmission on the interface."
SYNTAX INTEGER {
inbound(1), -- ingress interface
outbound(2) -- egress interface
}
--
-- Data Path
--
diffServDataPath OBJECT IDENTIFIER ::= { diffServMIBObjects 1 }
--
-- Data Path Table
--
-- The Data Path Table enumerates the Differentiated Services
-- Functional Data Paths within this device. Each entry in this table
-- is indexed by ifIndex and ifDirection. Each entry provides the
-- first Differentiated Services Functional Data Path Element to
-- process data flowing along specific data path. This table should
-- have at most two entries for each interface capable of
-- Differentiated Services processing on this device: ingress and
-- egress.
-- Note that Differentiated Services Functional Data Path Elements
-- linked together using their individual next pointers and anchored by
-- an entry of the diffServDataPathTable constitute a functional data
-- path.
--
diffServDataPathTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServDataPathEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The data path table contains RowPointers indicating the start of
the functional data path for each interface and traffic direction
in this device. These may merge, or be separated into parallel
data paths."
::= { diffServDataPath 1 }
diffServDataPathEntry OBJECT-TYPE
SYNTAX DiffServDataPathEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the data path table indicates the start of a single
Differentiated Services Functional Data Path in this device.
These are associated with individual interfaces, logical or
physical, and therefore are instantiated by ifIndex. Therefore,
the interface index must have been assigned, according to the
procedures applicable to that, before it can be meaningfully
used. Generally, this means that the interface must exist.
When diffServDataPathStorage is of type nonVolatile, however,
this may reflect the configuration for an interface whose ifIndex
has been assigned but for which the supporting implementation is
not currently present."
INDEX { ifIndex, diffServDataPathIfDirection }
::= { diffServDataPathTable 1 }
DiffServDataPathEntry ::= SEQUENCE {
diffServDataPathIfDirection IfDirection,
diffServDataPathStart RowPointer,
diffServDataPathStorage StorageType,
diffServDataPathStatus RowStatus
}
diffServDataPathIfDirection OBJECT-TYPE
SYNTAX IfDirection
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"IfDirection specifies whether the reception or transmission path
for this interface is in view."
::= { diffServDataPathEntry 1 }
diffServDataPathStart OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This selects the first Differentiated Services Functional Data
Path Element to handle traffic for this data path. This
RowPointer should point to an instance of one of:
diffServClfrEntry
diffServMeterEntry
diffServActionEntry
diffServAlgDropEntry
diffServQEntry
A value of zeroDotZero in this attribute indicates that no
Differentiated Services treatment is performed on traffic of this
data path. A pointer with the value zeroDotZero normally
terminates a functional data path.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the treatment is as if this
attribute contains a value of zeroDotZero."
::= { diffServDataPathEntry 2 }
diffServDataPathStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServDataPathEntry 3 }
diffServDataPathStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time."
::= { diffServDataPathEntry 4 }
--
-- Classifiers
--
diffServClassifier OBJECT IDENTIFIER ::= { diffServMIBObjects 2 }
--
-- Classifier Table
--
-- The Classifier Table allows multiple classifier elements, of same or
-- different types, to be used together. A classifier must completely
-- classify all packets presented to it. This means that all traffic
-- presented to a classifier must match at least one classifier element
-- within the classifier, with the classifier element parameters
-- specified by a filter.
-- If there is ambiguity between classifier elements of different
-- classifier, classifier linkage order indicates their precedence; the
-- first classifier in the link is applied to the traffic first.
-- Entries in the classifier element table serves as the anchor for
-- each classification pattern, defined in filter table entries. Each
-- classifier element table entry also specifies the subsequent
-- downstream Differentiated Services Functional Data Path Element when
-- the classification pattern is satisfied. Each entry in the
-- classifier element table describes one branch of the fan-out
-- characteristic of a classifier indicated in the Informal
-- Differentiated Services Model section 4.1. A classifier is composed
-- of one or more classifier elements.
diffServClfrNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for diffServClfrId, or a
zero to indicate that none exist."
::= { diffServClassifier 1 }
diffServClfrTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table enumerates all the diffserv classifier functional
data path elements of this device. The actual classification
definitions are defined in diffServClfrElementTable entries
belonging to each classifier.
An entry in this table, pointed to by a RowPointer specifying an
instance of diffServClfrStatus, is frequently used as the name
for a set of classifier elements, which all use the index
diffServClfrId. Per the semantics of the classifier element
table, these entries constitute one or more unordered sets of
tests which may be simultaneously applied to a message to
classify it.
The primary function of this table is to ensure that the value of
diffServClfrId is unique before attempting to use it in creating
a diffServClfrElementEntry. Therefore, the diffServClfrEntry must
be created on the same SET as the diffServClfrElementEntry, or
before the diffServClfrElementEntry is created."
::= { diffServClassifier 2 }
diffServClfrEntry OBJECT-TYPE
SYNTAX DiffServClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the classifier table describes a single classifier.
All classifier elements belonging to the same classifier use the
classifier's diffServClfrId as part of their index."
INDEX { diffServClfrId }
::= { diffServClfrTable 1 }
DiffServClfrEntry ::= SEQUENCE {
diffServClfrId IndexInteger,
diffServClfrStorage StorageType,
diffServClfrStatus RowStatus
}
diffServClfrId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the classifier entries. Managers
should obtain new values for row creation in this table by
reading diffServClfrNextFree."
::= { diffServClfrEntry 1 }
diffServClfrStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServClfrEntry 2 }
diffServClfrStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time. Setting this variable to
'destroy' when the MIB contains one or more RowPointers pointing
to it results in destruction being delayed until the row is no
longer used."
::= { diffServClfrEntry 3 }
--
-- Classifier Element Table
--
diffServClfrElementNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for diffServClfrElementId,
or a zero to indicate that none exist."
::= { diffServClassifier 3 }
diffServClfrElementTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServClfrElementEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The classifier element table enumerates the relationship between
classification patterns and subsequent downstream Differentiated
Services Functional Data Path elements.
diffServClfrElementSpecific points to a filter that specifies the
classification parameters. A classifier may use filter tables of
different types together.
One example of a filter table defined in this MIB is
diffServMultiFieldClfrTable, for IP Multi-Field Classifiers
(MFCs). Such an entry might identify anything from a single
micro-flow (an identifiable sub-session packet stream directed
from one sending transport to the receiving transport or
transports), or aggregates of those such as the traffic from a
host, traffic for an application, or traffic between two hosts
using an application and a given DSCP. The standard Behavior
Aggregate used in the Differentiated Services Architecture is
encoded as a degenerate case of such an aggregate - the traffic
using a particular DSCP value.
Filter tables for other filter types may be defined elsewhere."
::= { diffServClassifier 4 }
diffServClfrElementEntry OBJECT-TYPE
SYNTAX DiffServClfrElementEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the classifier element table describes a single
element of the classifier."
INDEX { diffServClfrId, diffServClfrElementId }
::= { diffServClfrElementTable 1 }
DiffServClfrElementEntry ::= SEQUENCE {
diffServClfrElementId IndexInteger,
diffServClfrElementPrecedence Unsigned32,
diffServClfrElementNext RowPointer,
diffServClfrElementSpecific RowPointer,
diffServClfrElementStorage StorageType,
diffServClfrElementStatus RowStatus
}
diffServClfrElementId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the Classifier Element entries.
Managers obtain new values for row creation in this table by
reading diffServClfrElementNextFree."
::= { diffServClfrElementEntry 1 }
diffServClfrElementPrecedence OBJECT-TYPE
SYNTAX Unsigned32 (1..4294967295)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The relative order in which classifier elements are applied:
higher numbers represent classifier element with higher
precedence. Classifier elements with the same order must be
unambiguous i.e. they must define non-overlapping patterns, and
are considered to be applied simultaneously to the traffic
stream. Classifier elements with different order may overlap in
their filters: the classifier element with the highest order
that matches is taken.
On a given interface, there must be a complete classifier in
place at all times in the ingress direction. This means one or
more filters must match any possible pattern. There is no such
requirement in the egress direction."
::= { diffServClfrElementEntry 2 }
diffServClfrElementNext OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This attribute provides one branch of the fan-out functionality
of a classifier described in the Informal Differentiated Services
Model section 4.1.
This selects the next Differentiated Services Functional Data
Path Element to handle traffic for this data path. This
RowPointer should point to an instance of one of:
diffServClfrEntry
diffServMeterEntry
diffServActionEntry
diffServAlgDropEntry
diffServQEntry
A value of zeroDotZero in this attribute indicates no further
Differentiated Services treatment is performed on traffic of this
data path. The use of zeroDotZero is the normal usage for the
last functional data path element of the current data path.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the treatment is as if this
attribute contains a value of zeroDotZero."
::= { diffServClfrElementEntry 3 }
diffServClfrElementSpecific OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A pointer to a valid entry in another table, filter table, that
describes the applicable classification parameters, e.g. an entry
in diffServMultiFieldClfrTable.
The value zeroDotZero is interpreted to match anything not
matched by another classifier element - only one such entry may
exist for each classifier.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the element is ignored."
::= { diffServClfrElementEntry 4 }
diffServClfrElementStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServClfrElementEntry 5 }
diffServClfrElementStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time. Setting this variable to
'destroy' when the MIB contains one or more RowPointers pointing
to it results in destruction being delayed until the row is no
longer used."
::= { diffServClfrElementEntry 6 }
--
-- IP Multi-field Classification Table
--
-- Classification based on six different fields in the IP header.
-- Functional Data Paths may share definitions by using the same entry.
--
diffServMultiFieldClfrNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for
diffServMultiFieldClfrId, or a zero to indicate that none exist."
::= { diffServClassifier 5 }
diffServMultiFieldClfrTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServMultiFieldClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A table of IP Multi-field Classifier filter entries that a
system may use to identify IP traffic."
::= { diffServClassifier 6 }
diffServMultiFieldClfrEntry OBJECT-TYPE
SYNTAX DiffServMultiFieldClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An IP Multi-field Classifier entry describes a single filter."
INDEX { diffServMultiFieldClfrId }
::= { diffServMultiFieldClfrTable 1 }
DiffServMultiFieldClfrEntry ::= SEQUENCE {
diffServMultiFieldClfrId IndexInteger,
diffServMultiFieldClfrAddrType InetAddressType,
diffServMultiFieldClfrDstAddr InetAddress,
diffServMultiFieldClfrDstPrefixLength InetAddressPrefixLength,
diffServMultiFieldClfrSrcAddr InetAddress,
diffServMultiFieldClfrSrcPrefixLength InetAddressPrefixLength,
diffServMultiFieldClfrDscp DscpOrAny,
diffServMultiFieldClfrFlowId Unsigned32,
diffServMultiFieldClfrProtocol Unsigned32,
diffServMultiFieldClfrDstL4PortMin InetPortNumber,
diffServMultiFieldClfrDstL4PortMax InetPortNumber,
diffServMultiFieldClfrSrcL4PortMin InetPortNumber,
diffServMultiFieldClfrSrcL4PortMax InetPortNumber,
diffServMultiFieldClfrStorage StorageType,
diffServMultiFieldClfrStatus RowStatus
}
diffServMultiFieldClfrId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the MultiField Classifier filter
entries. Managers obtain new values for row creation in this
table by reading diffServMultiFieldClfrNextFree."
::= { diffServMultiFieldClfrEntry 1 }
diffServMultiFieldClfrAddrType OBJECT-TYPE
SYNTAX InetAddressType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The type of IP address used by this classifier entry. While
other types of addresses are defined in the InetAddressType
textual convention, and DNS names, a classifier can only look at
packets on the wire. Therefore, this object is limited to IPv4
and IPv6 addresses."
::= { diffServMultiFieldClfrEntry 2 }
diffServMultiFieldClfrDstAddr OBJECT-TYPE
SYNTAX InetAddress
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The IP address to match against the packet's destination IP
address. This may not be a DNS name, but may be an IPv4 or IPv6
prefix. diffServMultiFieldClfrDstPrefixLength indicates the
number of bits that are relevant."
::= { diffServMultiFieldClfrEntry 3 }
diffServMultiFieldClfrDstPrefixLength OBJECT-TYPE
SYNTAX InetAddressPrefixLength
UNITS "bits"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The length of the CIDR Prefix carried in
diffServMultiFieldClfrDstAddr. In IPv4 addresses, a length of 0
indicates a match of any address; a length of 32 indicates a
match of a single host address, and a length between 0 and 32
indicates the use of a CIDR Prefix. IPv6 is similar, except that
prefix lengths range from 0..128."
DEFVAL { 0 }
::= { diffServMultiFieldClfrEntry 4 }
diffServMultiFieldClfrSrcAddr OBJECT-TYPE
SYNTAX InetAddress
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The IP address to match against the packet's source IP address.
This may not be a DNS name, but may be an IPv4 or IPv6 prefix.
diffServMultiFieldClfrSrcPrefixLength indicates the number of
bits that are relevant."
::= { diffServMultiFieldClfrEntry 5 }
diffServMultiFieldClfrSrcPrefixLength OBJECT-TYPE
SYNTAX InetAddressPrefixLength
UNITS "bits"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The length of the CIDR Prefix carried in
diffServMultiFieldClfrSrcAddr. In IPv4 addresses, a length of 0
indicates a match of any address; a length of 32 indicates a
match of a single host address, and a length between 0 and 32
indicates the use of a CIDR Prefix. IPv6 is similar, except that
prefix lengths range from 0..128."
DEFVAL { 0 }
::= { diffServMultiFieldClfrEntry 6 }
diffServMultiFieldClfrDscp OBJECT-TYPE
SYNTAX DscpOrAny
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The value that the DSCP in the packet must have to match this
entry. A value of -1 indicates that a specific DSCP value has not
been defined and thus all DSCP values are considered a match."
DEFVAL { -1 }
::= { diffServMultiFieldClfrEntry 7 }
diffServMultiFieldClfrFlowId OBJECT-TYPE
SYNTAX Unsigned32 (0..1048575)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The flow identifier in an IPv6 header."
::= { diffServMultiFieldClfrEntry 8 }
diffServMultiFieldClfrProtocol OBJECT-TYPE
SYNTAX Unsigned32 (0..255)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The IP protocol to match against the IPv4 protocol number or the
IPv6 Next- Header number in the packet. A value of 255 means
match all. Note the protocol number of 255 is reserved by IANA,
and Next-Header number of 0 is used in IPv6."
DEFVAL { 255 }
::= { diffServMultiFieldClfrEntry 9 }
diffServMultiFieldClfrDstL4PortMin OBJECT-TYPE
SYNTAX InetPortNumber
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The minimum value that the layer-4 destination port number in
the packet must have in order to match this classifier entry."
DEFVAL { 0 }
::= { diffServMultiFieldClfrEntry 10 }
diffServMultiFieldClfrDstL4PortMax OBJECT-TYPE
SYNTAX InetPortNumber
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The maximum value that the layer-4 destination port number in
the packet must have in order to match this classifier entry.
This value must be equal to or greater than the value specified
for this entry in diffServMultiFieldClfrDstL4PortMin."
DEFVAL { 65535 }
::= { diffServMultiFieldClfrEntry 11 }
diffServMultiFieldClfrSrcL4PortMin OBJECT-TYPE
SYNTAX InetPortNumber
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The minimum value that the layer-4 source port number in the
packet must have in order to match this classifier entry."
DEFVAL { 0 }
::= { diffServMultiFieldClfrEntry 12 }
diffServMultiFieldClfrSrcL4PortMax OBJECT-TYPE
SYNTAX InetPortNumber
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The maximum value that the layer-4 source port number in the
packet must have in order to match this classifier entry. This
value must be equal to or greater than the value specified for
this entry in diffServMultiFieldClfrSrcL4PortMin."
DEFVAL { 65535 }
::= { diffServMultiFieldClfrEntry 13 }
diffServMultiFieldClfrStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServMultiFieldClfrEntry 14 }
diffServMultiFieldClfrStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time. Setting this variable to
'destroy' when the MIB contains one or more RowPointers pointing
to it results in destruction being delayed until the row is no
longer used."
::= { diffServMultiFieldClfrEntry 15 }
--
-- Meters
--
diffServMeter OBJECT IDENTIFIER ::= { diffServMIBObjects 3 }
--
-- This MIB supports a variety of Meters. It includes a specific
-- definition for Token Bucket Meter, which are but one type of
-- specification. Other metering parameter sets can be defined in other
-- MIBs.
-- Multiple meter elements may be logically cascaded using their
-- diffServMeterSucceedNext and diffServMeterFailNext pointers if
-- required. One example of this might be for an AF PHB implementation
-- that uses multiple level conformance meters.
-- Cascading of individual meter elements in the MIB is intended to be
-- functionally equivalent to multiple level conformance determination
-- of a packet. The sequential nature of the representation is merely
-- a notational convenience for this MIB.
-- srTCM meters (RFC 2697) can be specified using two sets of
-- diffServMeterEntry and diffServTBParamEntry. The first set specifies
-- the Committed Information Rate and Committed Burst Size
-- token-bucket. The second set specifies the Excess Burst Size
-- token-bucket.
-- trTCM meters (RFC 2698) can be specified using two sets of
-- diffServMeterEntry and diffServTBParamEntry. The first set specifies
-- the Committed Information Rate and Committed Burst Size
-- token-bucket. The second set specifies the Peak Information Rate
-- and Peak Burst Size token-bucket.
-- tswTCM meters (RFC 2859) can be specified using two sets of
-- diffServMeterEntry and diffServTBParamEntry. The first set specifies
-- the Committed Target Rate token-bucket. The second set specifies
-- the Peak Target Rate token-bucket. diffServTBParamInterval in each
-- token bucket reflects the Average Interval.
--
diffServMeterNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for diffServMeterId, or a
zero to indicate that none exist."
::= { diffServMeter 1 }
diffServMeterTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServMeterEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table enumerates specific meters that a system may use to
police a stream of traffic. The traffic stream to be metered is
determined by the Differentiated Services Functional Data Path
Element(s) upstream of the meter i.e. by the object(s) that point
to each entry in this table. This may include all traffic on an
interface.
Specific meter details are to be found in table entry referenced
by diffServMeterSpecific."
::= { diffServMeter 2 }
diffServMeterEntry OBJECT-TYPE
SYNTAX DiffServMeterEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the meter table describes a single conformance level
of a meter."
INDEX { diffServMeterId }
::= { diffServMeterTable 1 }
DiffServMeterEntry ::= SEQUENCE {
diffServMeterId IndexInteger,
diffServMeterSucceedNext RowPointer,
diffServMeterFailNext RowPointer,
diffServMeterSpecific RowPointer,
diffServMeterStorage StorageType,
diffServMeterStatus RowStatus
}
diffServMeterId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the Meter entries. Managers obtain new
values for row creation in this table by reading
diffServMeterNextFree."
::= { diffServMeterEntry 1 }
diffServMeterSucceedNext OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"If the traffic does conform, this selects the next
Differentiated Services Functional Data Path element to handle
traffic for this data path. This RowPointer should point to an
instance of one of:
diffServClfrEntry
diffServMeterEntry
diffServActionEntry
diffServAlgDropEntry
diffServQEntry
A value of zeroDotZero in this attribute indicates that no
further Differentiated Services treatment is performed on traffic
of this data path. The use of zeroDotZero is the normal usage for
the last functional data path element of the current data path.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the treatment is as if this
attribute contains a value of zeroDotZero."
DEFVAL { zeroDotZero }
::= { diffServMeterEntry 2 }
diffServMeterFailNext OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"If the traffic does not conform, this selects the next
Differentiated Services Functional Data Path element to handle
traffic for this data path. This RowPointer should point to an
instance of one of:
diffServClfrEntry
diffServMeterEntry
diffServActionEntry
diffServAlgDropEntry
diffServQEntry
A value of zeroDotZero in this attribute indicates no further
Differentiated Services treatment is performed on traffic of this
data path. The use of zeroDotZero is the normal usage for the
last functional data path element of the current data path.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the treatment is as if this
attribute contains a value of zeroDotZero."
DEFVAL { zeroDotZero }
::= { diffServMeterEntry 3 }
diffServMeterSpecific OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This indicates the behavior of the meter by pointing to an entry
containing detailed parameters. Note that entries in that
specific table must be managed explicitly.
For example, diffServMeterSpecific may point to an entry in
diffServTBParamTable, which contains an instance of a single set
of Token Bucket parameters.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the meter always succeeds."
::= { diffServMeterEntry 4 }
diffServMeterStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServMeterEntry 5 }
diffServMeterStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time. Setting this variable to
'destroy' when the MIB contains one or more RowPointers pointing
to it results in destruction being delayed until the row is no
longer used."
::= { diffServMeterEntry 6 }
--
-- Token Bucket Parameter Table
--
diffServTBParam OBJECT IDENTIFIER ::= { diffServMIBObjects 4 }
-- Each entry in the Token Bucket Parameter Table parameterize a single
-- token bucket. Multiple token buckets can be used together to
-- parameterize multiple levels of conformance.
-- Note that an entry in the Token Bucket Parameter Table can be shared
-- by multiple diffServMeterTable entries.
--
diffServTBParamNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for diffServTBParamId, or a
zero to indicate that none exist."
::= { diffServTBParam 1 }
diffServTBParamTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServTBParamEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table enumerates a single set of token bucket meter
parameters that a system may use to police a stream of traffic.
Such meters are modeled here as having a single rate and a single
burst size. Multiple entries are used when multiple rates/burst
sizes are needed."
::= { diffServTBParam 2 }
diffServTBParamEntry OBJECT-TYPE
SYNTAX DiffServTBParamEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry that describes a single set of token bucket
parameters."
INDEX { diffServTBParamId }
::= { diffServTBParamTable 1 }
DiffServTBParamEntry ::= SEQUENCE {
diffServTBParamId IndexInteger,
diffServTBParamType AutonomousType,
diffServTBParamRate Unsigned32,
diffServTBParamBurstSize BurstSize,
diffServTBParamInterval Unsigned32,
diffServTBParamStorage StorageType,
diffServTBParamStatus RowStatus
}
diffServTBParamId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the Token Bucket Parameter entries.
Managers obtain new values for row creation in this table by
reading diffServTBParamNextFree."
::= { diffServTBParamEntry 1 }
diffServTBParamType OBJECT-TYPE
SYNTAX AutonomousType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The Metering algorithm associated with the Token Bucket
parameters. zeroDotZero indicates this is unknown.
Standard values for generic algorithms:
diffServTBParamSimpleTokenBucket, diffServTBParamAvgRate,
diffServTBParamSrTCMBlind, diffServTBParamSrTCMAware,
diffServTBParamTrTCMBlind, diffServTBParamTrTCMAware, and
diffServTBParamTswTCM are specified in this MIB as OBJECT-
IDENTITYs; additional values may be further specified in other
MIBs."
::= { diffServTBParamEntry 2 }
diffServTBParamRate OBJECT-TYPE
SYNTAX Unsigned32 (1..4294967295)
UNITS "kilobits per second"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The token-bucket rate, in kilobits per second (kbps). This
attribute is used for:
1. CIR in RFC 2697 for srTCM
2. CIR and PIR in RFC 2698 for trTCM
3. CTR and PTR in RFC 2859 for TSWTCM
4. AverageRate in RFC 3290."
::= { diffServTBParamEntry 3 }
diffServTBParamBurstSize OBJECT-TYPE
SYNTAX BurstSize
UNITS "Bytes"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The maximum number of bytes in a single transmission burst. This
attribute is used for:
1. CBS and EBS in RFC 2697 for srTCM
2. CBS and PBS in RFC 2698 for trTCM
3. Burst Size in RFC 3290."
::= { diffServTBParamEntry 4 }
diffServTBParamInterval OBJECT-TYPE
SYNTAX Unsigned32 (1..4294967295)
UNITS "microseconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The time interval used with the token bucket. For:
1. Average Rate Meter, the Informal Differentiated Services Model
section 5.2.1, - Delta.
2. Simple Token Bucket Meter, the Informal Differentiated
Services Model section 5.1, - time interval t.
3. RFC 2859 TSWTCM, - AVG_INTERVAL.
4. RFC 2697 srTCM, RFC 2698 trTCM, - token bucket update time
interval."
::= { diffServTBParamEntry 5 }
diffServTBParamStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServTBParamEntry 6 }
diffServTBParamStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time. Setting this variable to
'destroy' when the MIB contains one or more RowPointers pointing
to it results in destruction being delayed until the row is no
longer used."
::= { diffServTBParamEntry 7 }
--
-- OIDs for diffServTBParamType definitions.
--
diffServTBMeters OBJECT IDENTIFIER ::= { diffServMIBAdmin 1 }
diffServTBParamSimpleTokenBucket OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Two Parameter Token Bucket Meter as described in the Informal
Differentiated Services Model section 5.2.3."
::= { diffServTBMeters 1 }
diffServTBParamAvgRate OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Average Rate Meter as described in the Informal Differentiated
Services Model section 5.2.1."
::= { diffServTBMeters 2 }
diffServTBParamSrTCMBlind OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Single Rate Three Color Marker Metering as defined by RFC 2697,
in the `Color Blind' mode as described by the RFC."
REFERENCE
"RFC 2697"
::= { diffServTBMeters 3 }
diffServTBParamSrTCMAware OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Single Rate Three Color Marker Metering as defined by RFC 2697,
in the `Color Aware' mode as described by the RFC."
REFERENCE
"RFC 2697"
::= { diffServTBMeters 4 }
diffServTBParamTrTCMBlind OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Two Rate Three Color Marker Metering as defined by RFC 2698, in
the `Color Blind' mode as described by the RFC."
REFERENCE
"RFC 2698"
::= { diffServTBMeters 5 }
diffServTBParamTrTCMAware OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Two Rate Three Color Marker Metering as defined by RFC 2698, in
the `Color Aware' mode as described by the RFC."
REFERENCE
"RFC 2698"
::= { diffServTBMeters 6 }
diffServTBParamTswTCM OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Time Sliding Window Three Color Marker Metering as defined by
RFC 2859."
REFERENCE
"RFC 2859"
::= { diffServTBMeters 7 }
--
-- Actions
--
diffServAction OBJECT IDENTIFIER ::= { diffServMIBObjects 5 }
--
-- The Action Table allows enumeration of the different types of
-- actions to be applied to a traffic flow.
--
diffServActionNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for diffServActionId, or a
zero to indicate that none exist."
::= { diffServAction 1 }
diffServActionTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServActionEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The Action Table enumerates actions that can be performed to a
stream of traffic. Multiple actions can be concatenated. For
example, traffic exiting from a meter may be counted, marked, and
potentially dropped before entering a queue.
Specific actions are indicated by diffServActionSpecific which
points to an entry of a specific action type parameterizing the
action in detail."
::= { diffServAction 2 }
diffServActionEntry OBJECT-TYPE
SYNTAX DiffServActionEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each entry in the action table allows description of one
specific action to be applied to traffic."
INDEX { diffServActionId }
::= { diffServActionTable 1 }
DiffServActionEntry ::= SEQUENCE {
diffServActionId IndexInteger,
diffServActionInterface InterfaceIndexOrZero,
diffServActionNext RowPointer,
diffServActionSpecific RowPointer,
diffServActionStorage StorageType,
diffServActionStatus RowStatus
}
diffServActionId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the Action entries. Managers obtain
new values for row creation in this table by reading
diffServActionNextFree."
::= { diffServActionEntry 1 }
diffServActionInterface OBJECT-TYPE
SYNTAX InterfaceIndexOrZero
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The interface index (value of ifIndex) that this action occurs
on. This may be derived from the diffServDataPathStartEntry's
index by extension through the various RowPointers. However, as
this may be difficult for a network management station, it is
placed here as well. If this is indeterminate, the value is
zero.
This is of especial relevance when reporting the counters which
may apply to traffic crossing an interface:
diffServCountActOctets,
diffServCountActPkts,
diffServAlgDropOctets,
diffServAlgDropPkts,
diffServAlgRandomDropOctets, and |