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rfc:rfc3747

Network Working Group H. Hazewinkel, Ed. Request for Comments: 3747 I.Net Category: Standards Track D. Partain, Ed.

                                                              Ericsson
                                                            April 2004
           The Differentiated Services Configuration MIB

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 (2004).  All Rights Reserved.

Abstract

 This memo describes a MIB module that provides a conceptual layer
 between high-level "network-wide" policy definitions that effect
 configuration of the Differentiated Services (diffserv) subsystem and
 the instance-specific information that would include such details as
 the parameters for all the queues associated with each interface in a
 system.  This essentially provides an interface for configuring
 differentiated services at a conceptually higher layer than that of
 the Differentiated Services MIB.

Hazewinkel & Partain Standards Track [Page 1] RFC 3747 Differentiated Services Configuration MIB April 2004

Table of Contents

 1.  The Internet-Standard Management Framework . . . . . . . . . .  2
 2.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  2
 3.  Other Documents. . . . . . . . . . . . . . . . . . . . . . . .  3
 4.  Relationship to other MIBs . . . . . . . . . . . . . . . . . .  3
     4.1.  The Policy-based Management MIB Module . . . . . . . . .  3
     4.2.  The Differentiated Services MIB Module . . . . . . . . .  4
 5.  The Differentiated Services Configuration MIB Module Design. .  5
 6.  Template Cloning . . . . . . . . . . . . . . . . . . . . . . .  6
     6.1.  An Approach to Template Cloning. . . . . . . . . . . . .  6
     6.2.  Example. . . . . . . . . . . . . . . . . . . . . . . . .  7
           6.2.1.  The Initial Situation. . . . . . . . . . . . . .  8
           6.2.2.  The Configuration Template . . . . . . . . . . .  9
           6.2.3.  Applying the Template. . . . . . . . . . . . . . 11
           6.2.4.  Applying the Template Using SNMP Messages. . . . 14
 7.  Managed Objects Definitions (MIB Module) . . . . . . . . . . . 15
 8.  Security Considerations. . . . . . . . . . . . . . . . . . . . 20
 9.  Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . 22
 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22
     10.1. Normative References . . . . . . . . . . . . . . . . . . 22
     10.2. Informative References . . . . . . . . . . . . . . . . . 23
 11. Editors' Addresses . . . . . . . . . . . . . . . . . . . . . . 23
 12. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 24

1. The Internet-Standard Management Framework

 For a detailed overview of the documents that describe the current
 Internet-Standard Management Framework, please refer to section 7 of
 RFC 3410 [RFC3410].
 Managed objects are accessed via a virtual information store, termed
 the Management Information Base or MIB.  MIB objects are generally
 accessed through the Simple Network Management Protocol (SNMP).
 Objects in the MIB are defined using the mechanisms defined in the
 Structure of Management Information (SMI).  This memo specifies a MIB
 module that is compliant to the SMIv2, which is described in STD 58,
 RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
 [RFC2580].

2. Introduction

 This memo defines a MIB module that can be used to convey management
 information about desired network-wide Differentiated Services based
 policy behavior.  This module is designed to integrate with the
 Differentiated Services MIB module [RFC3289] in order to provide
 template configurations for the Differentiated Services MIB module.
 The MIB module defined in this memo (the DIFFSERV-CONFIG-MIB) may be

Hazewinkel & Partain Standards Track [Page 2] RFC 3747 Differentiated Services Configuration MIB April 2004

 used in combination with the Policy-based Management MIB module
 [PMMIBDR], but that is not a requirement.  Without the Policy-based
 Management MIB module, a management application must emulate behavior
 provided by the Policy-based Management MIB using equivalent "low-
 level" SNMP operations in normal manager/agent communication.
 Together, this memo, [RFC3289], and [PMMIBDR] represent an instance
 of an integrated architecture for both device-specific and network-
 wide policy (configuration) management, which is fully integrated
 with the Internet Standard Management Framework.
 The Differentiated Services MIB module [RFC3289] operates on a device
 level.  The MIB module in this memo, the DIFFSERV-CONFIG-MIB, creates
 a coherent configuration management view as an umbrella over
 [RFC3289].  That is, the DIFFSERV-CONFIG-MIB provides a conceptual
 Application Program Interface (API) for configuration of the
 Differentiated Services parameters.  Since the Differentiated
 Services MIB module is able to maintain configuration information,
 the DIFFSERV-CONFIG-MIB configuration API consists only of
 configuration template information and the start of the so-called
 functional datapath.

3. Other Documents

 It is assumed that the reader is familiar with Differentiated
 Services ([RFC2474] and [RFC2475]), the Policy-based Management MIB
 ([PMMIBDR]), and "Configuring Networks and Devices With SNMP"
 ([RFC3512]).  These documents include all of the necessary
 terminology for understanding this memo.  However, note that use of
 the MIB module in this memo does not require the use of [PMMIBDR].
 [RFC3512] also provides an example MIB module which may help in
 understanding the relationship between DIFFSERV-CONFIG-MIB and the
 Differentiated Services MIB in [RFC3289].

4. Relationship to other MIBs

 In this section, we describe the relationship of this MIB module to
 other MIB modules.  The overall architecture used for policy
 configuration management is described in [PMMIBDR].

4.1. The Policy-based Management MIB Module

 [PMMIBDR] defines a MIB module that enables policy-based
 configuration management of infrastructure using the Internet
 Standard Management Framework.  The document includes a table for
 configuring policies to be implemented, tables for storing the roles
 of elements on a particular device, a table for representing the
 capabilities of a device with respect to policy management, a table

Hazewinkel & Partain Standards Track [Page 3] RFC 3747 Differentiated Services Configuration MIB April 2004

 for referencing elements affected by a policy, as well as other
 infrastructure.  There is no requirement that [PMMIBDR] be used in
 conjunction with the MIB module defined in this memo.
 See [PMMIBDR] for a full description of the policy-based
 configuration framework it provides.

4.2. The Differentiated Services MIB Module

 The Differentiated Services MIB module [RFC3289] provides a common
 set of managed objects useful for configuring Differentiated Services
 parameters on a Differentiated Services capable device.  This is what
 is referred to as instance-level configuration.  It is the alteration
 of the instance-level information in that MIB module which may be
 done using the objects in the MIB module defined in this memo.
 It is recognized that vendors may include additional managed objects
 in their devices (via vendor-specific MIB modules) for configuring
 Differentiated Services parameters.  If a vendor chooses to use the
 objects defined in this memo for configuration, the vendor should
 provide additional managed objects in a similar approach as defined
 for the Differentiated Services MIB module.
 Since the managed objects of the Differentiated Services MIB
 [RFC3289] are not directly associated with an instance (interface and
 interface direction), the same managed objects can be used for
 traffic treatment configuration templates in a Differentiated
 Services capable device and can then be applied on multiple
 instances.  Therefore, the tables as defined in the Differentiated
 Services MIB can be used directly for template configuration
 purposes.  Those tables are:
  1. diffServClfrTable
  2. diffServClfrElementTable
  3. diffServMultiFieldClfrTable
  4. diffServMeterTable
  5. diffServTBParamTable
  6. diffServActionTable
  7. diffServDscpMarkActTable
  8. diffServCountActTable
  9. diffServAlgDropTable
  10. diffServRandomDropTable
  11. diffServQTable
  12. diffServSchedulerTable
  13. diffServMinRateTable
  14. diffServMaxRateTable

Hazewinkel & Partain Standards Track [Page 4] RFC 3747 Differentiated Services Configuration MIB April 2004

 Readers familiar with the Differentiated Services MIB will notice
 that these are all templates.  Only the diffServDataPathTable defines
 a managed instance for Differentiated Services traffic treatment by
 its indexes of the interface and its direction.  This also allows the
 tables mentioned above to be used as a configuration template without
 defining anything directly related to a managed instance.

5. The Differentiated Services Configuration MIB Module Design

 The Differentiated Services Configuration MIB module (in this memo)
 of the SNMP-based configuration management framework is positioned
 between the Policy-based Management MIB module and the instance-
 specific Differentiated Services MIB module as described above.
 The MIB module found in this memo is designed to maintain
 configuration templates for the Differentiated Services MIB [RFC3289]
 module.  The module only has a template table that describes a
 Differentiated Services traffic treatment by providing the starting
 pointer of the functional datapath.  The templates represent a
 specific configuration of traffic treatment in a functional datapath
 of a Differentiated Services capable device.  To avoid duplication of
 managed objects, the actual templates defining the functional
 datapath are defined in the Differentiated Services MIB module.
 These are also used for the management of the instances.  Therefore,
 the implementation of the DIFFSERV-CONFIG-MIB module uses the tables
 defined in the Differentiated Services MIB.  As soon as a
 configuration is made active via the POLICY-MANAGEMENT-MIB or using
 normal SNMP operations, the configuration defined within this MIB
 module will be instantiated in the DIFFSERV-MIB.
 Note that this is a conceptual process.  That is, the configuration
 may not actually go through an API available in the subsystem which
 implements the DIFFSERV-MIB module.  However, configuration via the
 DIFFSERV-CONFIG-MIB module will alter the same instrumentation as the
 DIFFSERV-MIB module whether it does it via the DIFFSERV-MIB module or
 not.
 The Differentiated Services Configuration MIB module only needs to
 define a starting point of a traffic treatment configuration
 template.  This table is similar to the diffServDataPathTable
 [RFC3289].  However, it has a semantic difference in that the
 diffServDataPathTable is associated with an instance (interface and
 interface direction), whereas the diffServConfigTable in this memo is
 not.

Hazewinkel & Partain Standards Track [Page 5] RFC 3747 Differentiated Services Configuration MIB April 2004

 Unlike most MIB modules, changes to the managed objects in this MIB
 module do not cause a change in the external/traffic behavior of the
 device.  This MIB module is used to set up per-hop-behavior
 configurations.  As soon as configurations are made active via the
 POLICY-MANAGEMENT-MIB or SNMP operations, the configurations defined
 within this MIB module will be instantiated in the DIFFSERV-MIB.
 The only table in this MIB module is the diffServConfigTable, which
 provides managed objects for registering traffic treatment
 configurations used in differentiated services.  The sole purpose of
 this table is to provide the starting point for a traffic treatment
 configuration template.  The traffic treatment itself is performed by
 functional datapath elements [RFC3289].

6. Template Cloning

 The concept of the DIFFSERV-CONFIG-MIB is based on having traffic
 treatment configuration templates.  The templates provide a set of
 configuration values that provide a particular behavior, such as
 Expedited Forwarding traffic treatment, in the functional datapath.
 The template (or functional datapath) is similar to a linked list
 from a starting point and each (functional datapath) element is
 connected to the next element via the so-called next RowPointer.
 The moment a template is activated (instantiated) on an interface and
 its interface direction, the template needs to be copied/cloned, so
 that the template remains as a template.  Note that the template is
 logically "locked" through the cloning process.  That is, the
 template cannot be changed part way through the cloning process.
 With the exception of the indices, the cloned template will be
 identical to the source template.
 A literal copy/clone of the template is not possible, since the same
 indices inside the element tables cannot be re-used.  The
 instantiation process must therefore generate a new index for each
 element.  As a result of this, the 'NEXT' pointers also need to be
 updated.  Otherwise, those will point to the template.

6.1. An Approach to Template Cloning

 What should a system containing Differentiated Services capabilities
 and Differentiated Services configuration capabilities do
 conceptually at the moment a template is activated on an interface?
 The following approach should not be considered implementation
 guidelines, but rather a conceptual explanation of what should be
 done.

Hazewinkel & Partain Standards Track [Page 6] RFC 3747 Differentiated Services Configuration MIB April 2004

    1) Get the index of the template to be activated
    2) Get RowPointer (current) from
          diffServConfigStart.index
          of the diffServConfigTable
    3) Check if RowPointer (current) exists
    4) Logically "lock" the entry (current) pointed to by
       RowPointer so that its values are not changed part way
       through the cloning process.
    5) Copy/Clone the entry (current) pointed to by RowPointer
          a) Get a new index for the entry
          b) Configure the new entry with the values
             of the entry to be cloned
          c) Update the NEXT pointer with a new RowPointer
             that pointed to the previous entry that was copied
             part of this template
    6) Store RowPointer of cloned entry as (previous) in order to
       update the NEXT pointer with the next cloned entry.
    7) Get the RowPointer of the next element in the template
       as (current)
    8) If (current) RowPointer does not equal zeroDotZero go to 4
    9) Logically "unlock" all the locked entries done by step 4).
 If a configuration/template is activated via a means other than a
 direct SNMP SET request, such as via the Policy-based Management MIB,
 the handling of the activation and potential error response code must
 be provided via that mechanism.  If a configuration/template is
 activated using SNMP SET requests, an accurate error response value
 must be returned.  For example, if a configuration/template has
 inconsistent values, the SNMP SET should return an error.  Whether
 the configuration is already finished is not of direct importance,
 since the SNMP SET response must be accurate.  On systems where the
 activation may take a long time, a response may be given prior to
 completion, but extra mechanisms must be provided to detect any
 errors.

6.2. Example

 This section provides an example of the process described in the
 previous section.  This example will show a Differentiated Services
 capable incoming (ingress) interface that only counts the traffic
 stream.  Then, with the policy-based configuration concept as defined
 in this document and in [PMMIBDR], a traffic marking configuration
 will be applied.  The example will walk the reader through all of the
 steps involved in this process.  Again, the use of [PMMIBDR] is
 simply an example and is not required.

Hazewinkel & Partain Standards Track [Page 7] RFC 3747 Differentiated Services Configuration MIB April 2004

    NOTE WELL:  For brevity and clarity, the example does not always
    show the complete entry (row) of a table.  The only objects shown
    are those needed for creating the row pointers to the next
    functional datapath element or needed to provide information about
    the specific parameters of the functional datapath elements.  The
    column named 'INDEX' always defines the complete index as defined
    for the associated entry.  In some cases, this is a combined index
    of multiple components.  Therefore, the names of the columns are
    omitted.
    Also note that the values Assured Forwarding and Expedited
    Forwarding are abstracted as DSCP(AF) and DSCP(EF) (respectively)
    or simply as AF and EF.  For the actual values refer to [RFC3289].

6.2.1. The Initial Situation

 The initial configuration is the existing configuration of an ingress
 interface.
    +------------------------------------------------------------+
    |   ingress functional datapath                              |
    |                        +----------+                        |
 -->|----------->----------->| count    |----------->----------->|-->
    |                        +----------+                        |
    +------------------------------------------------------------+
 This figure depicts a simple traffic treatment functional datapath
 for an ingress interface.  The functional datapath only consists of a
 count action.
 Within the DIFFSERV-MIB, this would be instantiated as follows.  Note
 that RowPointer objects must point to the first accessible columnar
 object in the conceptual row.  Thus, while perhaps more instructive
 to use the index value for the RowPointer object's value (e.g.,
 diffServCountActId.1) in the example, it would nonetheless be
 incorrect, and the first accessible columnar object has been used as
 should be done (e.g., diffServCountActOctets.1).
 diffServDataPathTable
 +-----------------+-----------------------------+--
 | INDEX           | diffServDataPathStart       |
 +-----------------+-----------------------------+--
 | ifIndex.ingress | diffServActionNext.1        |
 +-----------------+-----------------------------+--

Hazewinkel & Partain Standards Track [Page 8] RFC 3747 Differentiated Services Configuration MIB April 2004

 diffServActionTable
 +-------+--------------------+-------------------------+--
 | INDEX | diffServActionNext |diffServActionSpecific   |
 +-------+--------------------+-------------------------+--
 | 1     | 0.0                |diffServCountActOctets.1 |
 +-------+--------------------+-------------------------+--
 diffServCountActTable
 +-------+------------------------+--
 | INDEX | diffServCountActOctets |
 +-------+------------------------+--
 | 1     |                        |
 +-------+------------------------+--

6.2.2. The Configuration Template

 The following provides an example of a policy configuration in which
 traffic is classified by a specific IP filter, that results in two
 classifiers (one for the IP filter and one for match all).  Both
 streams are then metered, marked, and counted.  This is an example of
 usage on the edge (an ingress interface) of a Differentiated Services
 domain that wants to have Expedited Forwarding and Assured Forwarding
 marked traffic within the Differentiated Services domain.
 +------------------------------------------------------------+
 |   ingress functional datapath                              |
 |   +------------+   +-------+   +---------+   +---------+   |
 |   |            |   |       |   | action: |   | action: |   |

–>|–>| classifier |–>| meter |–>| mark EF |–>| count |–>|—–>

 |   | match <IP> |   |       |   |         |   |         |   |
 |   +------------+   +-------+   +---------+   +---------+   |
 |         |                 \                                |
 |         |                  \      +---------+              |
 |         |                   \     | action: |              |routing
 |         |                    * -->| dropper |              |core
 |         |                   /     |         |              |
 |         |                  /      +---------+              |
 |         V                 /                                |
 |   +------------+   +-------+   +---------+   +---------+   |
 |   |            |   |       |   | action: |   | action: |   |
 |   | classifier |-->| meter |-->| mark AF |-->| count   |-->|----->
 |   | match all  |   |       |   |         |   |         |   |
 |   +------------+   +-------+   +---------+   +---------+   |
 +------------------------------------------------------------+
 This figure depicts a policy configuration for ingress traffic
 treatment in a Differentiated Services capable device.  The

Hazewinkel & Partain Standards Track [Page 9] RFC 3747 Differentiated Services Configuration MIB April 2004

 configuration is represented as follows in the DIFFSERV-CONFIG-MIB
 module and the DIFFSERV-MIB module.
 Note that the original (existing) traffic treatment described in
 6.2.1 is also in the tables.
 Note also that in the diffServDscpMarkActTable, DSCP(EF) represents
 the DSCP value for Expedited Forwarding and DSCP(AF) represents the
 DSCP value for Assured Forwarding.

diffServConfigTable (in the MIB module in this memo) +——-+————————-+—————————+– | INDEX | diffServConfigStart | diffServConfigDescr | +——-+————————-+—————————+– | "foo" | diffServClfrStorage.1 | Example traffic treatment | +——-+————————-+—————————+–

diffServClfrTable +——-+———————+——————–+ | INDEX | diffServClfrStorage | diffServClfrStatus | +——-+———————+——————–+ | 1 | | | +——-+———————+——————–+

diffServClfrElementTable (shares index with diffServClfrTable) +——-+—————————+——————————-+– | INDEX | diffServClfrElementNext | diffServClfrElementPrecedence | +——-+—————————+——————————-+– | 1.1 |diffServMeterSucceedNext.1 | 1 | | 1.2 |diffServMeterSucceedNext.2 | 2 | +——-+—————————+——————————-+–

diffServMeterTable +——-+————————–+———————–+– | INDEX | diffServMeterSucceedNext |diffServMeterFailNext | +——-+————————–+———————–+– | 1 | diffServActionNext.2 | diffServAlgDropType.1 | | 2 | diffServActionNext.3 | diffServAlgDropType.1 | +——-+————————–+———————–+–

Hazewinkel & Partain Standards Track [Page 10] RFC 3747 Differentiated Services Configuration MIB April 2004

diffServActionTable +——-+———————-+—————————-+– | INDEX | diffServActionNext | diffServActionSpecific | +——-+———————-+—————————-+– | 1 | 0.0 | diffServCountActOctets.1 | | 2 | diffServActionNext.4 | diffServDscpMarkActDscp.EF | | 3 | diffServActionNext.5 | diffServDscpMarkActDscp.AF | | 4 | 0.0 | diffServCountActOctets.2 | | 5 | 0.0 | diffServCountActOctets.3 | +——-+———————-+—————————-+–

diffServCountActTable +——-+————————+– | INDEX | diffServCountActOctets | +——-+————————+– | 1 | | | 2 | | | 3 | | +——-+————————+–

diffServAlgDropTable +——-+———————+————————-+– | INDEX | diffServAlgDropType | diffServAlgDropSpecific | +——-+———————+————————-+– | 1 | alwaysDrop(5) | 0.0 | +——-+———————+————————-+–

diffServDscpMarkActTable +————————-+ | diffServDscpMarkActDscp | +————————-+ | DSCP(EF) | | DSCP(AF) | +————————-+

6.2.3. Applying the Template

 Now we have the original ingress interface configuration and the
 policy configuration we want to apply to the actual interface.
 The example policy must provide the required Differentiated Services
 traffic treatment to all interfaces used by system administrators.
 The traffic treatment required is described in 6.2.2 above.
 Therefore, we have the following example policy which is configured
 via the POLICY-BASED-MANAGEMENT-MIB module (see [PMMIBDR]):
 if ( roleMatch("Administrator") )

Hazewinkel & Partain Standards Track [Page 11] RFC 3747 Differentiated Services Configuration MIB April 2004

 then
    /*
     * The $0 gets the "element" returned from the previous
     * statement.  the .1 at the end is the ingress interface
     * This sets, for example, diffServDataPathStart.3.1 to be
     * "diffServConfigStart.3.f.o.o" if interface 3 has the role
     * "Administrator".
     */
    setVar("diffServDataPathStart.$0.1",
            "diffServConfigStart.3.f.o.o", Oid)
 For our purposes, we only apply this on the inbound (ingress)
 direction of the interface.
 Note that although object descriptors are used in this PolicyScript
 example, the object identifiers must be used in the running script.
 For more information on policies and their syntax refer to [PMMIBDR].
 The following tables in this section provide the cloned entries in
 the tables of the DIFFSERV-MIB module.  All tables may have columns
 that contain contents or administrative objects that are not shown.
 These columns do not determine a function in the datapath and they
 are not shown for clarity of the cloning mechanism.
 Note that the original (existing) traffic treatment of 6.2.1 and
 6.2.2 are also in the tables.

diffServConfigTable +——-+————————-+—————————+–

INDEX diffServConfigStart diffServConfigDescr

+——-+————————-+—————————+–

"foo" diffServClfrStorage.1 Example traffic treatment

+——-+————————-+—————————+–

diffServDataPathTable +—————–+—————————–+–

INDEX diffServDataPathStart

+—————–+—————————–+–

ifIndex.ingress diffServActionNext.2

+—————–+—————————–+–

Hazewinkel & Partain Standards Track [Page 12] RFC 3747 Differentiated Services Configuration MIB April 2004

diffServClfrTable +——-+———————+——————–+

INDEX diffServClfrStorage diffServClfrStatus

+——-+———————+——————–+

1
2

+——-+———————+——————–+

diffServClfrElementTable +——-+—————————-+——————————-+–

INDEX diffServClfrElementNext diffServClfrElementPrecedence

+——-+—————————-+——————————-+–

1.1 diffServMeterSucceedNext.1 1
1.2 diffServMeterSucceedNext.2 2
2.3 diffServMeterSucceedNext.3 1
2.4 diffServMeterSucceedNext.4 2

+——-+—————————-+——————————-+–

diffServMeterTable +——-+————————–+———————–+–

INDEX diffServMeterSucceedNext diffServMeterFailNext

+——-+————————–+———————–+–

1 diffServActionNext.2 diffServAlgDropType.1
2 diffServActionNext.3 diffServAlgDropType.1
3 diffServActionNext.6 diffServAlgDropType.2
4 diffServActionNext.7 diffServAlgDropType.2

+——-+————————–+———————–+–

diffServActionTable +——-+———————-+—————————-+–

INDEX diffServActionNext diffServActionSpecific

+——-+———————-+—————————-+–

1 0.0 diffServCountActOctets.1
2 diffServActionNext.4 diffServDscpMarkActDscp.EF
3 diffServActionNext.5 diffServDscpMarkActDscp.AF
4 0.0 diffServCountActOctets.2
5 0.0 diffServCountActOctets.3
6 diffServActionNext.8 diffServDscpMarkActDscp.EF
7 diffServActionNext.9 diffServDscpMarkActDscp.AF
8 0.0 diffServCountActOctets.4
9 0.0 diffServCountActOctets.5

+——-+———————-+—————————-+–

Hazewinkel & Partain Standards Track [Page 13] RFC 3747 Differentiated Services Configuration MIB April 2004

diffServCountActTable +——-+————————+–

INDEX diffServActCountOctets

+——-+————————+–

1
2
3
4
5

+——-+————————+–

diffServAlgDropTable +——-+———————+————————-+–

INDEX diffServAlgDropType diffServAlgDropSpecific

+——-+———————+————————-+–

1 alwaysDrop(5) 0.0

+——-+———————+————————-+–

diffServDscpMarkActTable +————————-+

diffServDscpMarkActDscp

+————————-+

DSCP(EF)
DSCP(AF)

+————————-+

 As one can see in the example, the main elements from which a
 functional datapath is constructed are duplicated/copied/cloned.
 That process is needed in order to preserve the policy configuration
 for reuse at a later time.
 It is up to the SNMP agent to keep track of which network interfaces
 are under policy control and which policy rules are being used.  This
 avoids duplication of policy enforcement.  How the agent does this is
 an implementation issue.
 One can see that the old functional datapath configurations stay in
 the MIB module tables.  It is up to the SNMP agent implementation to
 decide whether to delete stale entries or keep them.  Garbage
 collection of stale entries is an implementation issue.

6.2.4. Applying the Template Using SNMP Messages

 In this section, the above example is explained by using SNMP
 communication between the SNMP "manager" and the SNMP "agent".

Hazewinkel & Partain Standards Track [Page 14] RFC 3747 Differentiated Services Configuration MIB April 2004

 In order to apply the template to all interfaces that have a role
 match of "Administrator," the SNMP manager must have a list of the
 roles of the interface.  This means the SNMP manager must do an
 SNMP-SET for all those interfaces.  This is expressed in the
 following pseudo code function.
 set_template_if_administrator_interface(
          <interface_list>, <template_name>
 ) {
    template_oid = SNMP-GET("diffServConfigStart.<template_name>");
    foreach interface (<ifRole_list>) {
       if (interface.role == "Administrator") {
          SNMP-SET("diffServDataPathStart.$interface.1",
                Oid, template_oid);
       }
    }
 }
 For example, on a system with 3 interfaces, the following list would
 be known to the manager.  The first value indicates the interface
 number (ifIndex) and the second value is its role.
 interface_list IF_LIST = {
     { 1, ... , "Administrator", ... },
     { 2, ... , "User", ... },
     { 3, ... , "Administrator", ... } }
 This will result in the communication between a manager and agent of
 1 SNMP-GET and 2 SNMP-SETs:
  1. SNMP-GET("diffServConfigStart.3.f.o.o")
  2. SNMP-SET("diffServDataPathStart.1.1", Oid, "diffServActionNext.1")
  3. SNMP-SET("diffServDataPathStart.3.1", Oid, "diffServActionNext.1")

7. Managed Objects Definitions (MIB Module)

DIFFSERV-CONFIG-MIB DEFINITIONS ::= BEGIN

  IMPORTS
  OBJECT-TYPE, MODULE-IDENTITY,
  zeroDotZero, mib-2            FROM SNMPv2-SMI          -- [RFC2578]
  RowStatus, StorageType,
  RowPointer, DateAndTime       FROM SNMPv2-TC           -- [RFC2579]
  MODULE-COMPLIANCE,
  OBJECT-GROUP                  FROM SNMPv2-CONF         -- [RFC2580]

Hazewinkel & Partain Standards Track [Page 15] RFC 3747 Differentiated Services Configuration MIB April 2004

  SnmpAdminString               FROM SNMP-FRAMEWORK-MIB; -- [RFC3411]

diffServConfigMib MODULE-IDENTITY

  LAST-UPDATED "200401220000Z" -- 22 January 2004
  ORGANIZATION "SNMPCONF WG"
  CONTACT-INFO
     "SNMPCONF Working Group
      http://www.ietf.org/html.charters/snmpconf-charter.html
      WG mailing list: snmpconf@snmp.com
      Editors:
      Harrie Hazewinkel
      I.Net
      via Darwin 85
      20019 - Settimo Milanese (MI)
      Italy
      EMail: harrie@inet.it
      David Partain
      Ericsson AB
      P.O. Box 1248
      SE-581 12 Linkoping
      Sweden
      E-mail: David.Partain@ericsson.com"
  DESCRIPTION
      "This MIB module contains differentiated services
      specific managed objects to perform higher-level
      configuration management.  This MIB allows policies
      to use 'templates' to instantiate Differentiated
      Services functional datapath configurations to
      be assigned (associated with an interface and
      direction) when a policy is activated.
      Copyright (C) The Internet Society (2004).  This version
      of this MIB module is part of RFC 3747;  see the RFC
      itself for full legal notices."
  REVISION "200401220000Z" -- 22 January 2004
  DESCRIPTION
      "Initial version published as RFC 3747"
  ::= { mib-2 108 }

diffServConfigMIBObjects OBJECT IDENTIFIER ::= { diffServConfigMib 1 } diffServConfigMIBConformance OBJECT IDENTIFIER ::=

                                             { diffServConfigMib 2 }

– – The Differentiated Services configuration objects –

Hazewinkel & Partain Standards Track [Page 16] RFC 3747 Differentiated Services Configuration MIB April 2004

diffServConfigTable OBJECT-TYPE

  SYNTAX       SEQUENCE OF DiffServConfigEntry
  MAX-ACCESS   not-accessible
  STATUS       current
  DESCRIPTION
     "A table which defines the various per-hop-behaviors
     for which the system has default 'templates'."
  ::= { diffServConfigMIBObjects 2 }

diffServConfigEntry OBJECT-TYPE

  SYNTAX       DiffServConfigEntry
  MAX-ACCESS   not-accessible
  STATUS       current
  DESCRIPTION
     "An entry defining a per-hop-behavior.  Each entry in
     this table combines the various parameters (entries)
     into a specific per-hop-behavior.  Entries in this
     table might be defined by a vendor (pre-configured)
     or defined by a management application."
  INDEX { diffServConfigId }
  ::= { diffServConfigTable 1 }

DiffServConfigEntry ::= SEQUENCE {

  diffServConfigId           SnmpAdminString,
  diffServConfigDescr        SnmpAdminString,
  diffServConfigOwner        SnmpAdminString,
  diffServConfigLastChange   DateAndTime,
  diffServConfigStart        RowPointer,
  diffServConfigStorage      StorageType,
  diffServConfigStatus       RowStatus

}

diffServConfigId OBJECT-TYPE

  SYNTAX         SnmpAdminString (SIZE(1..116))
  MAX-ACCESS     not-accessible
  STATUS         current
  DESCRIPTION
    "A unique id for the per-hop-behavior policy for at
     least the SNMP agent.  For ease of administration the
     value may be unique within an administrative domain,
     but this is not required.
     The range of up to 116 octets is chosen to stay within
     the SMI limit of 128 sub-identifiers in an object
     identifier."
  ::= { diffServConfigEntry 1 }

diffServConfigDescr OBJECT-TYPE

Hazewinkel & Partain Standards Track [Page 17] RFC 3747 Differentiated Services Configuration MIB April 2004

  SYNTAX         SnmpAdminString
  MAX-ACCESS     read-create
  STATUS         current
  DESCRIPTION
     "A human-readable description to identify this defined
     per-hop-behavior.  Note that this is an SnmpAdminString,
     which permits UTF-8 strings.  An administratively assigned
     identifier for a template that would be unique within
     an administrative domain.  It is up to the management
     applications to agree how these are assigned within the
     administrative domain.  Once a description, such as
     'EF' is assigned, that has a certain set of parameters
     that achieve 'EF' from box to box. Management
     application code or script code can then scan
     the table to find the proper template and then
     assign it."
  ::= { diffServConfigEntry 2 }

diffServConfigOwner OBJECT-TYPE

  SYNTAX         SnmpAdminString
  MAX-ACCESS     read-create
  STATUS         current
  DESCRIPTION
     "The owner who created this entry."
  ::= { diffServConfigEntry 3 }

diffServConfigLastChange OBJECT-TYPE

  SYNTAX         DateAndTime
  MAX-ACCESS     read-only
  STATUS         current
  DESCRIPTION
     "The date and time when this entry was last changed."
  ::= { diffServConfigEntry 4 }

diffServConfigStart OBJECT-TYPE

  SYNTAX         RowPointer
  MAX-ACCESS     read-create
  STATUS         current
  DESCRIPTION
     "The pointer to a functional datapath configuration template as
     set up in the DIFFSERV-MIB.  This RowPointer should
     point to an instance of one of:
       diffServClfrEntry
       diffServMeterEntry
       diffServActionEntry
       diffServAlgDropEntry
       diffServQEntry

Hazewinkel & Partain Standards Track [Page 18] RFC 3747 Differentiated Services Configuration MIB April 2004

     A value of zeroDotZero in this attribute indicates no
     further Diffserv treatment is performed on traffic of
     this functional datapath.  This also means that the
     template described by this row is not defined.
     If the row pointed to does not exist, the treatment
     is as if this attribute contains a value of zeroDotZero."
  REFERENCE
     "Differentiated Services MIB module"
  DEFVAL { zeroDotZero }
  ::= { diffServConfigEntry 5 }

diffServConfigStorage OBJECT-TYPE

  SYNTAX         StorageType
  MAX-ACCESS     read-create
  STATUS         current
  DESCRIPTION
     "The type of storage used for this row.
     Since an entry in this table serves as a starting
     point for a configuration, it is recommended that
     all entries comprising the configuration started by
     diffServConfigStart follow the storage type of this
     entry.  Otherwise, after agent reboots a configuration
     may differ.  It may very well be that the agent is
     not capable of detecting such changes and therefore,
     the management application should verify the correct
     configuration after a reboot.  Rows with a StorageType
     of 'permanent' do not need to allow write access to
     any of the columnar objects in that row."
  DEFVAL { nonVolatile }
  ::= { diffServConfigEntry 6 }

diffServConfigStatus OBJECT-TYPE

  SYNTAX         RowStatus
  MAX-ACCESS     read-create
  STATUS         current
  DESCRIPTION
     "RowStatus object used for creation and deletion of
     rows in this table.  All writable objects in this row
     may be modified at any time."
  DEFVAL { notInService }
  ::= { diffServConfigEntry 7 }

– – MIB Compliance statements. –

Hazewinkel & Partain Standards Track [Page 19] RFC 3747 Differentiated Services Configuration MIB April 2004

diffServConfigMIBCompliances

 OBJECT IDENTIFIER ::= { diffServConfigMIBConformance 1 }

diffServConfigMIBGroups

 OBJECT IDENTIFIER ::= { diffServConfigMIBConformance 2 }

diffServConfigMIBFullCompliance MODULE-COMPLIANCE

  STATUS       current
  DESCRIPTION
     "The full compliance for this MIB module.
     For this compliance level the 'diffServMIBFullCompliance'
     must be met, since this MIB module depends on it in order
     to provide the configuration entries.
     "
  MODULE  -- This module
  MANDATORY-GROUPS {  diffServConfigMIBConfigGroup }
  OBJECT diffServConfigStatus
  SYNTAX RowStatus { active(1) }
  WRITE-SYNTAX RowStatus { createAndGo(4), destroy(6) }
  DESCRIPTION
     "Support for createAndWait and notInService is not required."
  ::= { diffServConfigMIBCompliances 1 }

diffServConfigMIBConfigGroup OBJECT-GROUP

  OBJECTS {  diffServConfigDescr,
             diffServConfigOwner,
             diffServConfigLastChange,
             diffServConfigStart,
             diffServConfigStorage,
             diffServConfigStatus
  }
  STATUS current
  DESCRIPTION
     "The per-hop-behavior Group defines the MIB objects that
     describe the configuration template for the per-hop-behavior."
  ::= { diffServConfigMIBGroups 1 }

END

8. Security Considerations

 There are a number of management objects defined in this MIB module
 with a MAX-ACCESS clause of read-write and/or read-create.  Such
 objects may be considered sensitive or vulnerable in some network
 environments.  The support for SET operations in a non-secure
 environment without proper protection can have a negative effect on
 network operations.  These managed objects are:

Hazewinkel & Partain Standards Track [Page 20] RFC 3747 Differentiated Services Configuration MIB April 2004

  1. The diffServConfigDescr, diffServConfigOwner, and

diffServConfigStatus are not security sensitive since these three

    objects do not affect any direct operational behavior of a
    diffserv capable device.
  1. Unauthorized change of the diffServConfigStart could lead to a

different configuration, and the 'changed' configuration could

    lead to different traffic treatment for the diffserv capable
    device than desired.
  1. Unauthorized change of the diffServConfigStorage could lead to

unknown behavior of the diffserv capable device after a reboot of

    the SNMP agent.  This may be caused by 'not having saved changes
    of the configuration' or unavailable configurations.
 In addition, the managed objects of the DIFFSERV-MIB are also
 security sensitive, since unauthorized changes may cause
 configuration changes.  For more detail, refer to [RFC3289].
 Allowing read access to objects in this MIB module is generally not
 considered sensitive, as read access only provides information that a
 template exists.  This is due to the fact that the managed objects
 that actually instantiate the template are in the DIFFSERV-MIB
 [RFC3289].  However, in environments where the template description
 (diffServConfigDescr) or owner (diffServConfigOwner) is considered
 sensitive information, appropriate access control should be exercised
 for these objects.
 SNMP versions prior to SNMPv3 did not include adequate security.
 Even if the network itself is secure (for example by using IPSec),
 there is no control as to who on the secure network is allowed to
 access and GET/SET (read/change/create/delete) the objects in this
 MIB module.
 It is RECOMMENDED that implementers consider the security features as
 provided by the SNMPv3 framework (see [RFC3410], section 8),
 including full support for the SNMPv3 cryptographic mechanisms (for
 authentication and privacy).
 Further, deployment of SNMP versions prior to SNMPv3 is NOT
 RECOMMENDED.  Instead, deployment of SNMPv3 with cryptographic
 security enabled is RECOMMENDED.  It is then a customer/operator
 responsibility to ensure that the SNMP entity giving access to an
 instance of this MIB module is properly configured to give access to
 the objects only to those principals (users) that have legitimate
 rights to GET or SET (change/create/delete) them.

Hazewinkel & Partain Standards Track [Page 21] RFC 3747 Differentiated Services Configuration MIB April 2004

9. Acknowledgments

 The editors gratefully acknowledge the significant contributions to
 this work made by several members of both the SNMPCONF and DiffServ
 working groups.

10. References

10.1. Normative References

 [RFC2578] McCloghrie, K., Perkins, D. and J. Schoenwaelder,
           "Structure of Management Information Version 2 (SMIv2)",
           STD 58, RFC 2578, April 1999.
 [RFC2579] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual
           Conventions for SMIv2", STD 58, RFC 2579, April 1999.
 [RFC2580] McCloghrie, K., Perkins, D. and J. Schoenwaelder,
           "Conformance Statements for SMIv2", STD 58, RFC 2580, April
           1999.
 [RFC3289] Baker, F., Chan, K. and A. Smith, "Management Information
           Base for the Differentiated Services Architecture", RFC
           3289, May 2002.
 [RFC3411] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture
           for Describing Simple Network Management Protocol (SNMP)
           Management Frameworks", STD 62, RFC 3411, December 2002.

Hazewinkel & Partain Standards Track [Page 22] RFC 3747 Differentiated Services Configuration MIB April 2004

10.2. Informative References

 [RFC3410] Case, J., Mundy, R., Partain, D. and B. Stewart,
           "Introduction and Applicability Statements for Internet-
           Standard Management Framework", RFC 3410, December 2002.
 [RFC2474] Nichols, K., Blake, S., Baker, F. and D. Black, "Definition
           of the Differentiated Services Field (DS Field) in the IPv4
           and IPv6 Headers", RFC 2474, December 1998.
 [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z. and
           W. Weiss, "An Architecture for Differentiated Services",
           RFC 2475, December 1998.
 [RFC3512] MacFaden, M., Partain, D., Saperia, J. and W. Tackabury,
           "Configuring Networks and Devices with Simple Network
           Management Protocol (SNMP)", RFC 3512, April 2003.
 [PMMIBDR] Waldbusser, S., Saperia, J. and T. Hongal, "Policy-based
           Management MIB", Work in Progress.

11. Editors' Addresses

 Harrie Hazewinkel
 I.Net
 via Darwin 85
 20019 - Settimo Milanese (MI)
 Italy
 EMail: harrie@inet.it
 David Partain
 Ericsson AB
 P.O. Box 1248
 SE-581 12 Linkoping
 Sweden
 EMail: David.Partain@ericsson.com

Hazewinkel & Partain Standards Track [Page 23] RFC 3747 Differentiated Services Configuration MIB April 2004

12. Full Copyright Statement

 Copyright (C) The Internet Society (2004).  This document is subject
 to the rights, licenses and restrictions contained in BCP 78 and
 except as set forth therein, the authors retain all their rights.
 This document and the information contained herein are provided on an
 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

 The IETF takes no position regarding the validity or scope of any
 Intellectual Property Rights or other rights that might be claimed to
 pertain to the implementation or use of the technology described in
 this document or the extent to which any license under such rights
 might or might not be available; nor does it represent that it has
 made any independent effort to identify any such rights.  Information
 on the procedures with respect to rights in RFC documents can be
 found in BCP 78 and BCP 79.
 Copies of IPR disclosures made to the IETF Secretariat and any
 assurances of licenses to be made available, or the result of an
 attempt made to obtain a general license or permission for the use of
 such proprietary rights by implementers or users of this
 specification can be obtained from the IETF on-line IPR repository at
 http://www.ietf.org/ipr.
 The IETF invites any interested party to bring to its attention any
 copyrights, patents or patent applications, or other proprietary
 rights that may cover technology that may be required to implement
 this standard.  Please address the information to the IETF at ietf-
 ipr@ietf.org.

Acknowledgement

 Funding for the RFC Editor function is currently provided by the
 Internet Society.

Hazewinkel & Partain Standards Track [Page 24]

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