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RFC3535 - Overview of the 2002 IAB Network Management Workshop

王朝other·作者佚名  2008-05-31
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Network Working Group J. Schoenwaelder

Request for Comments: 3535 International University Bremen

Category: Informational May 2003

Overview of the 2002 IAB Network Management Workshop

Status of this Memo

This memo provides information for the Internet community. It does

not specify an Internet standard of any kind. Distribution of this

memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2003). All Rights Reserved.

Abstract

This document provides an overview of a workshop held by the Internet

Architecture Board (IAB) on Network Management. The workshop was

hosted by CNRI in Reston, VA, USA on June 4 thru June 6, 2002. The

goal of the workshop was to continue the important dialog started

between network operators and protocol developers, and to guide the

IETFs focus on future work regarding network management. This report

summarizes the discussions and lists the conclusions and

recommendations to the Internet Engineering Task Force (IETF)

community.

Table of Contents

1. IntrodUCtion . . . . . . . . . . . . . . . . . . . . . . . . . 2

2. Network Management Technologies . . . . . . . . . . . . . . . 3

2.1 SNMP / SMI / MIBs . . . . . . . . . . . . . . . . . . . 4

2.2 COPS-PR / SPPI / PIBs . . . . . . . . . . . . . . . . . 5

2.3 CIM / MOF / UML / PCIM . . . . . . . . . . . . . . . . . 6

2.4 CLI / TELNET / SSH . . . . . . . . . . . . . . . . . . . 7

2.5 HTTP / Html . . . . . . . . . . . . . . . . . . . . . . 8

2.6 XML . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3. Operator Requirements . . . . . . . . . . . . . . . . . . . . 10

4. SNMP Framework Discussions . . . . . . . . . . . . . . . . . . 12

5. Consolidated Observations . . . . . . . . . . . . . . . . . . 14

6. Recommendations . . . . . . . . . . . . . . . . . . . . . . . 16

7. Security Considerations . . . . . . . . . . . . . . . . . . . 17

8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17

Normative References . . . . . . . . . . . . . . . . . . . . . . 18

Informative References . . . . . . . . . . . . . . . . . . . . . 18

Appendix - Participants . . . . . . . . . . . . . . . . . . . . . 19

Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 19

Full Copyright Statement . . . . . . . . . . . . . . . . . . . . 20

1. Introduction

The IETF has started several activities in the operations and

management area to develop technologies and standards that aim to

help network operators manage their networks. The main network

management technologies currently being developed within the IETF

are:

o The Simple Network Management Protocol (SNMP) [RFC3410] was

created in the late 1980s. The initial version (SNMPv1) is widely

deployed, while the latest version (SNMPv3), which addresses

security requirements, is just beginning to gain significant

deployment.

o The Common Information Model (CIM) [CIM], developed by the

Distributed Management Task Force (DMTF), has been extended in

cooperation with the DMTF to describe high-level policies as rule

sets (PCIM) [RFC3060]. Mappings of the CIM policy extensions to

LDAP schemas have been defined and work continues to define

specific schema extension for QoS and security policies.

o The Common Open Policy Service (COPS) [RFC2748] protocol has been

extended to provision configuration information on devices (COPS-

PR) [RFC3084]. Work is underway to define data definitions for

specific services such as Differentiated Services (DiffServ).

During 2001, several meetings have been organized at various events

(NANOG-22 May 2001, RIPE-40 October 2001, LISA-XV December 2001,

IETF-52 December 2001) to start a direct dialog between network

operators and protocol developers. During these meetings, several

operators have eXPressed their opinion that the developments in the

IETF do not really address their requirements, especially for

configuration management. This naturally leads to the question of

whether the IETF should refocus resources, and which strategic future

activities in the operations and management area should be started.

The Internet Architecture Board (IAB), on June 4 thru June 6, 2002,

held an invitational workshop on network management. The goal of the

workshop was to continue the important dialog started between network

operators and protocol developers, and to guide the IETFs focus on

future work regarding network management.

The workshop started with two breakout session to (a) identify a list

of technologies relevant for network management together with their

strengths and weaknesses, and to (b) identify the most important

operator needs. The results of these discussions are documented in

Section 2 and Section 3. During the following discussions, many more

specific characteristics of the current SNMP framework were

identified. These discussions are documented in Section 4. Section

5 defines a combined feature list that was developed during the

discussions following the breakout sessions. Section 6 gives

concrete recommendations to the IETF.

The following text makes no explicit distinction between different

versions of SNMP. For the majority of the SNMP related statements,

the protocol version is irrelevant. Nevertheless, some statements

are more applicable to SNMPv1/SNMPv2c environments, while other

statements (especially those concerned with security) are more

applicable to SNMPv3 environments.

2. Network Management Technologies

During the breakout sessions, the protocol developers assembled a

list of the various network management technologies that are

available or under active development. For each technology, a list

of strong (+) and weak (-) points were identified. There are also

some characteristics which appear to be neutral (o).

The list does not attempt to be complete. Focus was given to IETF

specific technologies (SNMP, COPS-PR, PCIM) and widely used

proprietary technologies (CLI, HTTP/HTML, XML). The existence of

other generic management technologies (such as TL1, CORBA, CMIP/GDMO,

TMN) or specific management technologies for specific problem domains

(such as RADIUS, DHCP, BGP, OSPF) were acknowledged, but were not the

focus of discussion.

2.1 SNMP / SMI / MIBs

The SNMP management technology was created in the late 1980s and has

since been widely implemented and deployed in the Internet. There is

lots of implementational and operational experience, and the

characteristics of the technology are thus well understood.

+ SNMP works reasonably well for device monitoring. The stateless

nature of SNMP is useful for statistical and status polling.

+ SNMP is widely deployed for basic monitoring. Some core MIB

modules, such as the IF-MIB [RFC2863], are implemented on most

networking devices.

+ There are many well defined proprietary MIB modules developed by

network device vendors to support their management products.

+ SNMP is an important data source for systems that do event

correlation, alarm detection, and root cause analysis.

o SNMP requires applications to be useful. SNMP was, from its early

days, designed as a programmatic interface between management

applications and devices. As such, using SNMP without management

applications or smart tools appears to be more complicated.

o Standardized MIB modules often lack writable MIB objects which can

be used for configuration, and this leads to a situation where the

interesting writable objects exist in proprietary MIB modules.

- There are scaling problems with regard to the number of objects in

a device. While SNMP provides reasonable performance for the

retrieval of a small amount of data from many devices, it becomes

rather slow when retrieving large amounts of data (such as routing

tables) from a few devices.

- There is too little deployment of writable MIB modules. While

there are some notable exceptions in areas, such as cable modems

where writable MIB modules are essential, it appears that router

equipment is usually not fully configurable via SNMP.

- The SNMP transactional model and the protocol constraints make it

more complex to implement MIBs, as compared to the implementation

of commands of a command line interface interpreter. A logical

operation on a MIB can turn into a sequence of SNMP interactions

where the implementation has to maintain state until the operation

is complete, or until a failure has been determined. In case of a

failure, a robust implementation must be smart enough to roll the

device back into a consistent state.

- SNMP does not support easy retrieval and playback of

configurations. One part of the problem is that it is not easy to

identify configuration objects. Another part of the problem is

that the naming system is very specific and physical device

reconfigurations can thus break the capability to play back a

previous configuration.

- There is often a semantic mismatch between the task-oriented view

of the world usually preferred by operators and the data-centric

view of the world provided by SNMP. Mapping from a task-oriented

view to the data-centric view often requires some non-trivial code

on the management application side.

- Several standardized MIB modules lack a description of high-level

procedures. It is often not obvious from reading the MIB modules

how certain high-level tasks are accomplished, which leads to

several different ways to achieve the same goal, which increases

costs and hinders interoperability.

A more detailed discussion about the SNMP management technology can

be found in Section 4.

2.2 COPS-PR / SPPI / PIBs

The COPS protocol [RFC2748] was defined in the late 1990s to support

policy control over QoS signaling protocols. The COPS-PR extension

allows provision policy information on devises.

+ COPS-PR allows high-level transactions for single devices,

including deleting one configuration and replacing it with

another.

+ COPS-PRs non-overlapping instance namespace normally ensures that

no other manager can corrupt a specific configuration. All

transactions for a given instance namespace are required to be

executed in-order.

+ Both manager and device states are completely synchronized with

one another at all times. If there is a failure in communication,

the state is resynchronized when the network is operating properly

again and the device's network configuration is valid.

+ The atomicity of transactions is well-defined. If there is any

failure in a transaction, that specific failure is reported to the

manager, and the local configuration is supposed to be

automatically rolled-back to the state of the last "good"

transaction.

+ Capability reporting is part of the framework PIB which must be

supported by COPS-PR implementations. This allows management

applications to adapt to the capabilities present on a device.

+ The focus of COPS-PR is configuration, and the protocol has been

optimized for this purpose (by using for example TCP as a

transport mechanism).

o Only a single manager is allowed to have control, at any point in

time, for a given subject category on a device. (The subject

category maps to a COPS Client-Type.) This single manager

assumption simplifies the protocol as it makes it easier to

maintain shared state.

o Similar to SNMP, COPS-PR requires applications to be useful since

it is also designed as a programmatic interface between management

applications and devices.

- As of the time of the meeting, there are no standardized PIB

modules.

- Compared to SNMP, there is not yet enough experience to understand

the strong and weak ASPects of the protocol in operational

environments.

- COPS-PR does not support easy retrieval and playback of

configurations. The reasons are similar as for SNMP.

- The COPS-PR view of the world is data-centric, similar to SNMP's

view of the world. A mapping from the data-centric view to a

task-oriented view and vice versa, has similar complexities as

with SNMP.

2.3 CIM / MOF / UML / PCIM

The development of the Common Information Model (CIM) [CIM] started

in the DMTF in the mid 1990s. The development follows a top-down

approach where core classes are defined first and later extended to

model specific services. The DMTF and the IETF jointly developed

policy extensions of the CIM, known as PCIM [RFC3060].

+ The CIM technology generally follows principles of object-

orientation with full support of methods on data objects, which is

not available in SNMP or COPS-PR.

+ The MOF format allows representation of instances in a common

format. No such common format exists for SNMP or COPS-PR. It is

of course possible to store instances in the form of BER encoded

ASN.1 sequences, but this is generally not suitable for human

readability.

+ There is support for a query facility which allows the locating of

CIM objects. However, the query language itself is not yet

specified as part of the CIM standards. Implementations currently

use proprietary query languages, such as the Windows Management

Instrumentation Query Language (WQL).

+ The information modeling work in CIM is done by using Unified

Modeling Language (UML) as a graphical notation. This attracts

people with a computer science background who have learned to use

UML as part of their education.

o The main practical use of CIM schemas today seems to be the

definition of data structures used internally by management

systems.

- The CIM schemas have rather complex interrelationships that must

be understood before one can reasonably extend the set of existing

schemas.

- Interoperability between CIM implementations seems to be

problematic compared to the number of interoperable SNMP

implementations available today.

- So far, CIM schemas have seen limited implementation and usage as

an interface between management systems and network devices.

2.4 CLI / TELNET / SSH

Most devices have a builtin command line interface (CLI) for

configuration and troubleshooting purposes. Network Access to the

CLI has traditionally been through the TELNET protocol, while the SSH

protocol is gaining momentum to address security issues associated

with TELNET. In the following, only CLIs that actually parse and

execute commands are considered. (Menu-oriented interfaces are

difficult for automation and thus not relevant here.)

+ Command line interfaces are generally task-oriented, which make

them easier to use for human operators.

+ A saved sequence of textual commands can easily be replayed.

Simple substitutions can be made with arbitrary text processing

tools.

+ It is usually necessary to learn at least parts of the command

line interface of new devices in order to create the initial

configuration. Once people have learned (parts of) the command

line interface, it is natural for them to use the same interface

and abstractions for automating configuration changes.

+ A command line interface does not require any special purpose

applications (telnet and ssh are readily available on most systems

today).

+ Most command line interfaces provide context sensitive help that

reduces the learning curve.

- Some command line interfaces lack a common data model. It is very

well possible that the same command on different devices, even

from the same vendor, behaves differently.

- The command line interface is primarily targeted to humans which

can adapt to minor syntax and format changes easily. Using

command line interfaces as a programmatic interface is troublesome

because of parsing complexities.

- Command line interfaces often lack proper version control for the

syntax and the semantics. It is therefore time consuming and

error prone to maintain programs or scripts that interface with

different versions of a command line interface.

- Since command line interfaces are proprietary, they can not be

used efficiently to automate processes in an environment with a

heterogenous set of devices.

- The access control facilities, if present at all, are often ad-hoc

and sometimes insufficient.

2.5 HTTP / HTML

Many devices have an embedded web server which can be used to

configure the device and to oBTain status information. The commonly

used protocol is HTTP, and information is rendered in HTML. Some

devices also expect that clients have facilities such as Java or Java

Script.

+ Embedded web servers for configuration are end-user friendly and

solution oriented.

+ Embedded web servers are suitable for configuring consumer devices

by inexperienced users.

+ Web server configuration is widely deployed, especially in boxes

targeted to the consumer market.

+ There is no need for specialized applications to use embedded web

servers since web browsers are commonly available today.

- Embedded web servers are management application hostile. Parsing

HTML pages to extract useful information is extremely painful.

- Replay of configuration is often problematic, either because the

web pages rely on some active content or because different

versions of the same device use different ways to interact with

the user.

- The access control facilities, if present at all, are often ad-hoc

and sometimes insufficient.

2.6 XML

In the late 1990's, some vendors started to use the Extensible Markup

Language (XML) [XML] for describing device configurations and for

protocols that can be used to retrieve and manipulate XML formatted

configurations.

+ XML is a machine readable format which is easy to process and

there are many good off the shelf tools available.

+ XML allows the description of structured data of almost arbitrary

complexity.

+ The basic syntax rules behind XML are relatively easy to learn.

+ XML provides a document-oriented view of configuration data

(similar to many proprietary configuration file formats).

+ XML has a robust schema language XSD [XSD] for which many good off

the shelf tools exist.

o XML alone is just syntax. XML schemas must be carefully designed

to make XML truly useful as a data exchange format.

- XML is rather verbose. This either increases the bandwidth

required to move management information around (which is an issue

in e.g., wireless or asymmetric cable networks) or it requires

that the systems involved have the processing power to do on the

fly compression/decompression.

- There is a lack of commonly accepted standardized management

specific XML schemas.

3. Operator Requirements

During the breakout session, the operators were asked to identify

needs that have not been sufficiently addressed. The results

produced during the breakout session were later discussed and

resulted in the following list of operator requirements.

1. Ease of use is a key requirement for any network management

technology from the operators point of view.

2. It is necessary to make a clear distinction between configuration

data, data that describes operational state and statistics. Some

devices make it very hard to determine which parameters were

administratively configured and which were obtained via other

mechanisms such as routing protocols.

3. It is required to be able to fetch separately configuration data,

operational state data, and statistics from devices, and to be

able to compare these between devices.

4. It is necessary to enable operators to concentrate on the

configuration of the network as a whole rather than individual

devices.

5. Support for configuration transactions across a number of devices

would significantly simplify network configuration management.

6. Given configuration A and configuration B, it should be possible

to generate the operations necessary to get from A to B with

minimal state changes and effects on network and systems. It is

important to minimize the impact caused by configuration changes.

7. A mechanism to dump and restore configurations is a primitive

operation needed by operators. Standards for pulling and pushing

configurations from/to devices are desirable.

8. It must be easy to do consistency checks of configurations over

time and between the ends of a link in order to determine the

changes between two configurations and whether those

configurations are consistent.

9. Network wide configurations are typically stored in central

master databases and transformed into formats that can be pushed

to devices, either by generating sequences of CLI commands or

complete configuration files that are pushed to devices. There

is no common database schema for network configuration, although

the models used by various operators are probably very similar.

It is desirable to extract, document, and standardize the common

parts of these network wide configuration database schemas.

10. It is highly desirable that text processing tools such as diff,

and version management tools such as RCS or CVS, can be used to

process configurations, which implies that devices should not

arbitrarily reorder data such as access control lists.

11. The granularity of access control needed on management interfaces

needs to match operational needs. Typical requirements are a

role-based access control model and the principle of least

privilege, where a user can be given only the minimum access

necessary to perform a required task.

12. It must be possible to do consistency checks of access control

lists across devices.

13. It is important to distinguish between the distribution of

configurations and the activation of a certain configuration.

Devices should be able to hold multiple configurations.

14. SNMP access control is data-oriented, while CLI access control is

usually command (task) oriented. Depending on the management

function, sometimes data-oriented or task-oriented access control

makes more sense. As such, it is a requirement to support both

data-oriented and task-oriented access control.

So far, there is no published document that clearly defines the

requirements of the operators.

4. SNMP Framework Discussions

During the discussions, many properties of the SNMP framework were

identified.

1. It is usually not possible to retrieve complete device

configurations via SNMP so that they can be compared with

previous configurations or checked for consistency across

devices. There is usually only incomplete coverage of device

features via the SNMP interface, and there is a lack of

differentiation between configuration data and operational state

data for many features.

2. The quality of SNMP instrumentations is sometimes disappointing.

SNMP access sometimes crashes systems or returns wrong data.

3. MIB modules and their implementations are not available in a

timely manner (sometimes MIB modules lag years behind) which

forces users to use the CLI.

4. Operators view current SNMP programming/scripting interfaces as

being too low-level and thus too time consuming and inconvenient

for practical use.

5. Lexicographic ordering is sometimes artificial with regard to

internal data structures and causes either significant runtime

overhead, or increases implementation costs or implementation

delay or both.

6. Poor performance for bulk data transfers. The typical examples

are routing tables.

7. Poor performance on query operations that were not anticipated

during the MIB design. A typical example is the following query:

Which outgoing interface is being used for a specific destination

address?

8. The SNMP credentials and key management are considered complex,

especially since they do not integrate well with other existing

credential and key management systems.

9. The SMI language is hard to deal with and not very practical.

10. MIB modules are often over-engineered in the sense that they

contain lots of variables that operators do not look at.

11. SNMP traps are used to track state changes but often syslog

messages are considered more useful since they usually contain

more information to describe the problem. SNMP traps usually

require subsequent get operations to figure out what the trap

really means.

12. Device manufacturers find SNMP instrumentations inherently

difficult to implement, especially with complex table indexing

schemes and table interrelationships.

13. MIB modules often lack a description of how the various objects

can be used to achieve certain management functions. (MIB

modules can often be characterized as a list of ingredients

without a recipe.)

14. The lack of structured types and various RPC interactions

(methods) make MIB modules much more complex to design and

implement.

15. The lack of query and aggregation capabilities (reduction of

data) causes efficiency and scalability problems.

16. The SNMP protocol was simplified in terms of the number of

protocol operations and resource requirements on managed devices.

It was not simplified in terms of usability by network operators

or instrumentation implementors.

17. There is a semantic mismatch between the low-level data-oriented

abstraction level of MIB modules and the task-oriented

abstraction level desired by network operators. Bridging the gap

with tools is in principle possible, but in general it is

expensive as it requires some serious development and programming

efforts.

18. SNMP seems to work reasonably well for small devices which have a

limited number of managed objects and where end-user management

applications are shipped by the vendor. For more complex

devices, SNMP becomes too expensive and too hard to use.

19. There is a disincentive for vendors to implement SNMP equivalent

MIB modules for all their CLI commands because they do not see a

valued proposition. This undermines the value of third party

standard SNMP solutions.

20. Rapid feature development is in general not compatible with the

standardization of the configuration interface.

5. Consolidated Observations

1. Programmatic interfaces have to provide full coverage otherwise

they will not be used by network operators since they have to

revert to CLIs anyway.

2. Operators perceive that equipment vendors do not implement MIB

modules in a timely manner. Neither read-only nor read-write MIB

modules are available on time today.

3. The attendees perceive that right now it is too hard to implement

useful MIB modules within network equipment.

4. Because of the previous items, SNMP is not widely used today for

network device configuration, although there are notable

exceptions.

5. It is necessary to clearly distinguish between configuration data

and operational data.

6. It would be nice to have a single data definition language for

all programmatic interfaces (in case there happen to be multiple

programmatic interfaces).

7. In general, there is a lack of input from the enterprise network

space. Those enterprises who provided input tend to operate

their networks like network operators.

8. It is required to be able to dump and reload a device

configuration in a textual format in a standard manner across

multiple vendors and device types.

9. It is desirable to have a mechanism to distribute configurations

to devices under transactional constraints.

10. Eliminating SNMP altogether is not an option.

11. Robust access control is needed. In addition, it is desirable to

be able to enable/disable individual MIB modules actually

implemented on a device.

12. Textual configuration files should be able to contain

international characters. Human-readable strings should utilize

the least-bad internationalized character set and encoding, which

this year almost certainly means UTF-8. Protocol elements should

be in case insensitive ASCII.

13. The deployed tools for event/alarm correlation, root cause

analysis and logging are not sufficient.

14. There is a need to support a human interface and a programmatic

interface.

15. The internal method routines for both interfaces should be the

same to ensure that data exchanged between these two interfaces

is always consistent.

16. The implementation costs have to be low on devices.

17. The implementation costs have to be low on managers.

18. The specification costs for data models have to be low.

19. Standardization costs for data models have to be low.

20. There should be a single data modeling language with a human

friendly syntax.

21. The data modeling language must support compound data types.

22. There is a need for data aggregation capabilities on the devices.

23. There should be a common data interchange format for instance

data that allows easy post-processing and analysis.

24. There is a need for a common data exchange format with single and

multi-system transactions (which implies rollback across devices

in error situations).

25. There is a need to reduce the semantic mismatch between current

data models and the primitives used by operators.

26. It should be possible to perform operations on selected subsets

of management data.

27. It is necessary to discover the capabilities of devices.

28. There is a need for a secure transport, authentication, identity,

and access control which integrates well with existing key and

credential management infrastructure.

29. It must be possible to define task oriented views and access

control rules.

30. The complete configuration of a device should be doable with a

single protocol.

31. A configuration protocol must be efficient and reliable and it

must scale in the number of transactions and devices.

32. Devices must be able to support minimally interruptive

configuration deltas.

33. A solution must support function call semantics (methods) to

implement functions, such as a longest prefix match on a routing

table.

6. Recommendations

1. The workshop recommends that the IETF stop forcing working groups

to provide writable MIB modules. It should be the decision of

the working group whether they want to provide writable objects

or not.

2. The workshop recommends that a group be formed to investigate why

current MIB modules do not contain all the objects needed by

operators to monitor their networks.

3. The workshop recommends that a group be formed to investigate why

the current SNMP protocol does not satisfy all the monitoring

requirements of operators.

4. The workshop recommends, with strong consensus from both protocol

developers and operators, that the IETF focus resources on the

standardization of configuration management mechanisms.

5. The workshop recommends, with strong consensus from the operators

and rough consensus from the protocol developers, that the

IETF/IRTF should spend resources on the development and

standardization of XML-based device configuration and management

technologies (such as common XML configuration schemas, exchange

protocols and so on).

6. The workshop recommends, with strong consensus from the operators

and rough consensus from the protocol developers, that the

IETF/IRTF should not spend resources on developing HTML-based or

HTTP-based methods for configuration management.

7. The workshop recommends, with rough consensus from the operators

and strong consensus from the protocol developers, that the IETF

should continue to spend resources on the evolution of the

SMI/SPPI data definition languages as being done in the SMIng

working group.

8. The workshop recommends, with split consensus from the operators

and rough consensus from the protocol developers, that the IETF

should spend resources on fixing the MIB development and

standardization process.

The workshop also discussed the following items and achieved rough

consensus, but did not make a recommendation.

1. The workshop had split consensus from the operators and rough

consensus from the protocol developers, that the IETF should not

focus resources on CIM extensions.

2. The workshop had rough consensus from the protocol developers

that the IETF should not spend resources on COPS-PR development.

So far, the operators have only very limited experience with

COPS-PR. In general, however, they felt that further development

of COPS-PR might be a waste of resources as they assume that

COPS-PR does not really address their requirements.

3. The workshop had rough consensus from the protocol developers

that the IETF should not spend resources on SPPI PIB definitions.

The operators had rough consensus that they do not care about

SPPI PIBs.

7. Security Considerations

This document is a report of an IAB Network Management workshop. As

such, it does not have any direct security implications for the

Internet.

8. Acknowledgments

The editor would like to thank Dave Durham, Simon Leinen and John

Schnizlein for taking detailed minutes during the workshop.

Normative References

[RFC3410] Case, J., Mundy, R., Partain, D. and B. Stewart,

"Introduction and Applicability Statements for Internet-

Standard Management Framework", RFC3410, December 2002.

[CIM] Distributed Management Task Force, "Common Information

Model (CIM) Specification Version 2.2", DSP 0004, June

1999.

[RFC3060] Moore, B., Ellesson, E., Strassner, J. and A. Westerinen,

"Policy Core Information Model -- Version 1

Specification", RFC3060, February 2001.

[RFC2748] Durham, D., Boyle, J., Cohen, R., Herzog, S., Rajan, R.

and A. Sastry, "The COPS (Common Open Policy Service)

Protocol", RFC2748, January 2000.

[RFC3084] Chan, K., Seligson, J., Durham, D., Gai, S., McCloghrie,

K., Herzog, S., Reichmeyer, F., Yavatkar, R. and A. Smith,

"COPS Usage for Policy Provisioning (COPS-PR)", RFC3084,

March 2001.

[XML] Bray, T., Paoli, J. and C. Sperberg-McQueen, "Extensible

Markup Language (XML) 1.0", W3C Recommendation, February

1998.

Informative References

[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group

MIB", RFC2863, June 2000.

[XSD] David, D., "XML Schema Part 0: Primer", W3C

Recommendation, May 2001.

Appendix - Participants

Ran Atkinson Extreme Networks

Rob Austein InterNetShare

Andy Bierman Cisco Systems

Steve Bellovin AT&T

Randy Bush AT&T

Leslie Daigle VeriSign

David Durham Intel

Vijay Gill

Wes Hardaker Network Associates Laboratories

Ed Kern

Simon Leinen Switch

Ken Lindahl University of California Berkeley

David Partain EriCsson

Andrew Partan UUnet/Verio/MFN

Vern Paxson ICIR

Aiko Pras Univeristy of Twente

Randy Presuhn BMC Software

Juergen Schoenwaelder University of Osnabrueck

John Schnizlein Cisco Systems

Mike St. Johns

Ruediger Volk Deutsche Telekom

Steve Waldbusser

Margaret Wassermann Windriver

Glen Waters Nortel Networks

Bert Wijnen Lucent

Author's Address

Comments should be submitted to the <nm-ws@ops.ietf.org> mailing

list.

Juergen Schoenwaelder

International University Bremen

P.O. Box 750 561

28725 Bremen

Germany

Phone: +49 421 200 3587

EMail: j.schoenwaelder@iu-bremen.de

Full Copyright Statement

Copyright (C) The Internet Society (2003). All Rights Reserved.

This document and translations of it may be copied and furnished to

others, and derivative works that comment on or otherwise explain it

or assist in its implementation may be prepared, copied, published

and distributed, in whole or in part, without restriction of any

kind, provided that the above copyright notice and this paragraph are

included on all such copies and derivative works. However, this

document itself may not be modified in any way, such as by removing

the copyright notice or references to the Internet Society or other

Internet organizations, except as needed for the purpose of

developing Internet standards in which case the procedures for

copyrights defined in the Internet Standards process must be

followed, or as required to translate it into languages other than

English.

The limited permissions granted above are perpetual and will not be

revoked by the Internet Society or its successors or assignees.

This document and the information contained herein is provided on an

"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING

TASK FORCE DISCLAIMS 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.

Acknowledgement

Funding for the RFCEditor function is currently provided by the

Internet Society.

 
 
 
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