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Versions: 00 01 02 RFC 4602

Network Working Group                                       Tom Pusateri
Internet-Draft                                          Juniper Networks
Expires: July 11, 2005                                      January 2005





            PIM IETF Proposed Standard Requirements Analysis
                   draft-ietf-pim-proposed-req-00.txt



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1.  Introduction

   This analysis provides supporting documentation to advance the
   Protocol Independent Multicast (PIM) routing protocol from the IETF
   Experimental status to Proposed Standard. PIM was first published as
   RFC 2117 in 1997 and then again as RFC 2362 in 1998. The protocol was
   classified as Experimental in both of these documents. The PIM
   protocol specification was then rewritten in whole in order to more
   fully specify the protocol.  It is this new specification that is to
   be advanced to Proposed Standard.




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2.  RFC 1264 Requirements

   Section 4.0 of RFC 1264 [ROUTESTD] describes the requirements for
   routing protocols to advance to Proposed Standard. Each requirement
   is listed below along with an explanation of how the requirement has
   been satisfied.


2.1.  Documents specifying the Protocol and its Usage

   The authors of the new PIM specification have taken considerable care
   to fully specify the protocol operation. It removes all known
   ambiguities and tries to normalize corner cases that existed in the
   previous specification. It has been used to provide several
   interoperable implementations by developers that were not authors of
   the specification.  These implementations will be described below.


2.2.  Management Information Base

   A Management Information Base for PIM is currently specified in RFC
   2934 [PIMMIB].  This MIB has many implementations and has been used
   by network management applications for several years. Updates to this
   MIB to support IPv6 and other improvements based on operation
   experience are in progress in the PIM Working Group of the IETF.


2.3.  Explicit Security Architecture

   The new PIM protocol specification contains an extensive security
   section explaining its security features and limitations. Data
   integrity protection and groupwise data origin authentication is
   provided for PIM protocol messages.


2.4.  Implementation Existence

   There are at least 4 known independent implementations of the new
   protocol specification and there are over 6 independent
   implementations of a previous version (RFC 2362) of the
   specification. The new specification was carefully written to be
   backward compatible with the old specification allowing
   implementations compliant with RFC 2362 to also be compliant with the
   new specification.

   The 4 implementations of the new version are described below:





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   XORP
      The XORP project [XORP] has an open-source implementation of PIM-
      SMv2 as specified in the draft-ietf-pim-sm-v2-new-11.txt.  It was
      written by Pavlin Radoslavov <pavlin@icir.org> and has been
      available to the public since December 2002.  Pavlin is not an
      author of the protocol specification. It does not use any other
      existing code as a base.

   Cisco IOS/IOX
      Cisco Systems, Inc. has written an implementation of the new
      protocol specification which has been deployed in production
      routers.  There exists an IOS implementation for IPv6 only. There
      exists an IOX implementation for both IPv4 and IPv6. This code was
      initially written by Isidor Kouvelas <kouvelas@cisco.com>. It does
      not depend on any existing code base.  Isidor is a co-author of
      the protocol specification.

   Infosys Technologies, Ltd.
      Infosys Technologies, Ltd. (www.infosys.com) have developed a
      limited shared tree implementation of the new specification
      including PIM Hello messages, DR election, PIM join/prune
      messages, join suppression, and prune override. It was written by
      Bharat Joshi <<bharat_joshi@infosys.com> and is used in commercial
      products.  Bharat is not an author of the protocol specification.

   Procket Networks
      An implementation was written from scratch at Procket Networks by
      Dino Farinacci <dino@cisco.com>. This implementation is now owned
      by Cisco Systems, Inc. Dino is not an author of the new protocol
      speicfication.


2.5.  Evidence of Testing


   Cisco
      The Cisco implementation has undergone extensive laboratory
      testing as well as testing in production deployments. It is found
      to interoperate with implementations of earlier versions of the
      PIM protocol specification.


   XORP
      The XORP PIM-SM implementation has been thoughtfully tested
      internally by the XORP project. The emphasis during testing has
      been on correctness. In a typical setup, a PIM-SM router's
      behavior is tested by connecting it to external packet generators
      and observers. The packet generators are used to generate messages



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      such as IGMP and PIM-SM control packets, and multicast data
      packets.  The packet observers are used to observe the PIM-SM
      control packets generated by the PIM-SM router under test, and to
      observe the data packets that may be forwarded by that router. In
      addition, the router's command-line interface has been used to
      observe its internal state during some of the tests.

      The test scenarios have been designed to closely follow the
      protocol specification (e.g., a separate test has been created for
      each event in the various protocol state machines, etc). All test
      scenarios are described in detail in [XORP-Test].

      The major tested features are:

      1. Multicast data forwarding.

      2. PIM Hello messages exchange, PIM router neighbor discovery,
         option exchange, and DR election.

      3. PIM Register messages transmission and reception, PIM Register
         state machine, multicast data packets encapsulation and
         decapsulation.

      4. Transmission and reception of PIM Join/Prune messages, upstream
         and downstream protocol state machines. The tests consider the
         following state: (*,*,RP), (*,G), (S,G) and (S,G,rpt).

      5. Transmission and reception of PIM Assert messages and the per-
         interface (*,G) and (S,G) Assert state machines.

      6. PIM Bootstrap mechanism: transmission, reception and forwarding
         of PIM Bootstrap messages, transmission and reception of PIM
         Cand-RP-Adv messages, candidate and non-candidate BSR state
         machines, creating the RP-Set at the BSR, receiving and using
         the RP-Set, semantic fragmentation of BSMs.

      In the final tests, the tested router behaved as specified in the
      PIM-SM protocol specification. All issues found in the protocol
      specification itself have been corrected in earlier versions of
      the Internet Draft.

   Procket Networks
      The Procket Networks implementation was deployed in many research
      and service provider networks and showed interoperability with new
      and old Cisco Systems implementations as well as Juniper Networks
      implementations.





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2.6.  Suitability

   PIM Sparse-Mode is a protocol for efficiently routing multicast
   groups that may span wide-area (and inter-domain) Internets.  PIM
   uses the underlying unicast routing to provide reverse-path
   information for multicast tree building but it is not dependent on
   any particular unicast routing protocol.


2.7.  Authentication Mechanisms

   PIM specifies the use of the IP security authentication header to
   provide data integrity protection and groupwise data origin
   authentication of protocol messages. The specific AH authentication
   algorithm and parameters, including the choice of authentication
   algorithm and the choice of key, are configured by the network
   administrator. The threats associated with receiving forged PIM
   messages are outlined in the security considerations section of the
   protocol specification.


3.  Acknowledgments

   Pavlin Radoslavov provided text for the section on XORP testing.
   Dino Farinacci provided text for the Procket Networks testing.


4.  Normative References


   [PIMMIB]    McCloghrie, K., Farinacci, D., Thaler, D., Fenner, B.,
               "Protocol Independent Multicast MIB for IPv4", RFC 2934,
               October 2000.


5.  Informative References


   [ROUTESTD]  Hinden, R., "Internet Routing Protocol Standardization
               Criteria", RFC 1264, October 1991.

   [XORP]      XORP Project, http://www.xorp.org/

   [XORP-Test] XORP PIM-SM Test Suite,
               http://www.xorp.org/releases/current/docs/pim_test-
               suite/pim_testsuite.pdf





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6.  Author's Address


   Tom Pusateri
   Juniper Networks, Inc.
   1194 North Mathilda Avenue
   Sunnyvale, CA 94089 USA
   Phone:    (408) 745-2000
   EMail:    pusateri@juniper.net



7.  Full Copyright Statement

   Copyright (C) The Internet Society (2005).  This document is subject
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   except as set forth therein, the authors retain all their rights.


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   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE."























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                             Table of Contents


   1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . .   1
   2. RFC 1264 Requirements  . . . . . . . . . . . . . . . . . . . .   2
   2.1. Documents specifying the Protocol and its Usage  . . . . . .   2
   2.2. Management Information Base  . . . . . . . . . . . . . . . .   2
   2.3. Explicit Security Architecture . . . . . . . . . . . . . . .   2
   2.4. Implementation Existence . . . . . . . . . . . . . . . . . .   2
   2.5. Evidence of Testing  . . . . . . . . . . . . . . . . . . . .   3
   2.6. Suitability  . . . . . . . . . . . . . . . . . . . . . . . .   5
   2.7. Authentication Mechanisms  . . . . . . . . . . . . . . . . .   5
   3. Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . .   5
   4. Normative References . . . . . . . . . . . . . . . . . . . . .   5
   5. Informative References . . . . . . . . . . . . . . . . . . . .   5
   6. Author's Address . . . . . . . . . . . . . . . . . . . . . . .   6
   7. Full Copyright Statement . . . . . . . . . . . . . . . . . . .   6
   8. Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . .   6

































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