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Internet Engineering Task Force (IETF) L. Zheng Request for Comments: 7063 Huawei Technologies Category: Informational Z. Zhang ISSN: 2070-1721 Juniper Networks

                                                             R. Parekh
                                                         Cisco Systems
                                                         December 2013

Survey Report on Protocol Independent Multicast - Sparse Mode (PIM-SM)

                  Implementations and Deployments

Abstract

 This document provides supporting documentation to advance the IETF
 stream's Protocol Independent Multicast - Sparse Mode (PIM-SM)
 protocol from Proposed Standard to Internet Standard.

Status of This Memo

 This document is not an Internet Standards Track specification; it is
 published for informational purposes.

 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Not all documents
 approved by the IESG are a candidate for any level of Internet
 Standard; see Section 2 of RFC 5741.

 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc7063.

Copyright Notice

 Copyright (c) 2013 IETF Trust and the persons identified as the
 document authors.  All rights reserved.

 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Zheng, et al. Informational [Page 1] RFC 7063 Survey Report on PIM-SM December 2013

Table of Contents

 1. Motivation ......................................................3
    1.1. Overview of PIM-SM .........................................3
    1.2. Requirements of RFCs 2026 and 6410 .........................3
 2. Survey on Implementations and Deployments .......................4
    2.1. Methodology ................................................4
    2.2. Operator Responses .........................................4
         2.2.1. Description of PIM-SM Deployments ...................4
         2.2.2. PIM-SM Deployment with Other Multicast
                Technologies ........................................4
         2.2.3. PIM-SM Rendezvous Points (RPs) and RP
                Discovery Mechanisms ................................4
    2.3. Vendor Responses ...........................................5
         2.3.1. Implementations Based on RFCs 4601 and 2362 .........5
         2.3.2. Lack of (*,*,RP) and PMBR Implementations ...........5
         2.3.3. Implementations of Other Features of RFC 4601 .......5
    2.4. Key Findings ...............................................6
 3. Security Considerations .........................................6
 4. Acknowledgements ................................................6
 5. References ......................................................6
    5.1. Normative References .......................................6
    5.2. Informative References .....................................7
 Appendix A. Questionnaire ..........................................8
   A.1. PIM Survey for Operators ....................................8
   A.2. PIM Survey for Implementors ................................10

Zheng, et al. Informational [Page 2] RFC 7063 Survey Report on PIM-SM December 2013

1. Motivation

1.1. Overview of PIM-SM

 Protocol Independent Multicast - Sparse Mode (PIM-SM) was first
 published as [RFC2117] in 1997.  This version was then obsoleted by
 [RFC2362] in 1998.  The protocol was classified as Experimental in
 both documents.  The protocol specification was then rewritten in
 whole and advanced to Proposed Standard as [RFC4601] in 2006.
 Considering its multiple independent implementations developed and
 sufficient successful operational experience gained, the PIM WG
 decided to advance the PIM-SM protocol to Internet Standard.  The
 conducted survey and this document are part of the work.

1.2. Requirements of RFCs 2026 and 6410

 [RFC2026] defines the stages in the standardization process, the
 requirements for moving a document between stages, and the types of
 documents used during this process.  Section 4.1.2 of [RFC2026]
 states that:

    The requirement for at least two independent and interoperable
    implementations applies to all of the options and features of the
    specification.  In cases in which one or more options or features
    have not been demonstrated in at least two interoperable
    implementations, the specification may advance to the Draft
    Standard level only if those options or features are removed.

 [RFC6410] updates the IETF Standards Process defined in [RFC2026].
 Primarily, it reduces the Standards Process from three Standards
 Track maturity levels to two.  The second maturity level is a
 combination of Draft Standard and Standard as specified in [RFC2026].
 Section 2.2 of [RFC6410] states that:

    (1) There are at least two independent interoperating
    implementations with widespread deployment and successful
    operational experience.

    (2)...

    (3) There are no unused features in the specification that greatly
    increase implementation complexity.

 Optional features that do not meet the aforesaid criteria have been
 identified by the PIM Working Group and will be removed.  This
 document provides supporting documentation to advance the IETF
 stream's Protocol Independent Multicast - Sparse Mode (PIM-SM)
 protocol from Proposed Standard to Internet Standard.

Zheng, et al. Informational [Page 3] RFC 7063 Survey Report on PIM-SM December 2013

2. Survey on Implementations and Deployments

2.1. Methodology

 A questionnaire was issued by the PIM WG co-chairs and announced
 widely to the vendors and operational community to obtain information
 on PIM-SM implementations and deployments.  The survey concluded on
 22 Oct 2012.  The responses remain confidential and only combined
 results are published here, while responders chose whether to keep
 their affiliations confidential.  The raw questionnaire is shown in
 Appendix A, and a compilation of the responses is included in the
 following section.

2.2. Operator Responses

 Nine operators responded to the survey.  They are SWITCH, National
 Research Council Canada, South Dakota School of Mines and Technology,
 Motorola Solutions, and five anonymous operators.

2.2.1. Description of PIM-SM Deployments

 Since 1998, PIM-SM has been deployed for a wide variety of
 applications: Campus, Enterprise, Research and WAN networks,
 Broadband ISP, and Digital TV.  There are five deployments based on
 [RFC4601] implementations and two on [RFC2362] implementations.  PIM-
 SM for IPv6 has been deployed by three operators.  Out of the nine
 operators, six have deployed PIM-SM implementations from multiple
 vendors.

 Operators reported minor interoperability issues and these were
 addressed by the vendors.  There was no major interoperability
 concern reported by the operators.

2.2.2. PIM-SM Deployment with Other Multicast Technologies

 Except for one deployment of PIM-SM with Multicast Extensions to OSPF
 (MOSPF), all other operators have deployed PIM-SM exclusively.  No
 operators acknowledged deployments of either (*,*,RP) or PIM
 Multicast Border Route (PMBR) for interconnection between PIM-SM and
 other multicast domains.

2.2.3. PIM-SM Rendezvous Points (RPs) and RP Discovery Mechanisms

 The number of PIM-SM RPs deployed by operators ranges from a few
 (e.g., sixteen) to a massively scaled number (four hundred).  Both
 static configuration and Bootstrap Router (BSR) have been deployed as
 RP discovery mechanisms.

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 Anycast-RP has been deployed for RP redundancy.  Two operators have
 deployed Anycast-RP using the Multicast Source Discovery Protocol
 (MSDP) [RFC3446].  Three operators have deployed Anycast-RP using
 both MSDP [RFC3446] and PIM [RFC4610] for different scenarios.  The
 best common practice seems to be to use static-RP configuration with
 Anycast-RP for redundancy.

2.3. Vendor Responses

 Eight vendors reported PIM-SM implementations.  They are XORP, Huawei
 Technologies, Cisco Systems, Motorola Solutions, Juniper Networks,
 and three other anonymous vendors.

2.3.1. Implementations Based on RFCs 4601 and 2362

 Four vendors reported PIM-SM implementations based on [RFC4601] and
 two reported PIM-SM implementations based on [RFC2362].  Two other
 reported implementations are hybrids.

 Minor interoperability issues have been addressed by the vendors over
 the years and no concerns were reported by any vendor.

2.3.2. Lack of (*,*,RP) and PMBR Implementations

 Most vendors have not implemented (*,*,RP) state as specified in
 [RFC4601] either due to lack of deployment requirements or due to
 security concerns.  Similarly, most vendors have also not implemented
 PMBR due to lack of deployment requirements or because it was
 considered too complex and non-scalable.

 Only one vendor, XORP, reported (*,*,RP) and PMBR implementation and
 they were implemented just because these were part of the [RFC4601]
 specification.

2.3.3. Implementations of Other Features of RFC 4601

 Most vendors have implemented all of the following from the [RFC4601]
 specification:

 o  Source-Specific Multicast (SSM)

 o  Join suppression

 o  Explicit tracking

 o  Register mechanism

 o  Shortest Path Tree (SPT) switchover at last-hop router

Zheng, et al. Informational [Page 5] RFC 7063 Survey Report on PIM-SM December 2013

 o  Assert mechanism

 o  Hashing of group to RP mappings

 Some vendors do not implement explicit tracking and SSM.

2.4. Key Findings

 PIM-SM has been widely implemented and deployed for different
 applications.  The protocol is sufficiently well specified in
 [RFC4601] resulting in interoperable implementation deployed by
 operators.

 There are no deployments and only one known implementation of
 (*,*,RP) and PMBR as specified in [RFC4601].  Hence, it is necessary
 to remove these features from the specification as required by
 [RFC2026] and [RFC6410].

3. Security Considerations

 The PIM WG is aware of at least three (and believes there are more)
 PIM-SM implementations that support the use of IPsec to protect PIM
 messages.  For at least one of them, IPsec is not part of the PIM
 implementation itself -- one just configures IPsec with Security
 Policy Databases (SPDs) where interface, the ALL_PIM_ROUTERS
 multicast address, etc., can be used as selectors, according to
 [RFC5796].

4. Acknowledgements

 The authors would like to thank Tim Chown and Bill Atwood, who helped
 to collect and anonymize the responses as the neutral third party.
 Special thanks are also given to Alexander Gall, William F. Maton
 Sotomayor, Steve Bauer, Sonum Mathur, Pavlin Radoslavov, Shuxue Fan,
 Sameer Gulrajani, and to the anonymous responders.

5. References

5.1. Normative References

 [RFC2026]  Bradner, S., "The Internet Standards Process -- Revision
            3", BCP 9, RFC 2026, October 1996.

 [RFC6410]  Housley, R., Crocker, D., and E. Burger, "Reducing the
            Standards Track to Two Maturity Levels", BCP 9, RFC 6410,
            October 2011.

Zheng, et al. Informational [Page 6] RFC 7063 Survey Report on PIM-SM December 2013

5.2. Informative References

 [RFC2117]  Estrin, D., Farinacci, D., Helmy, A., Thaler, D., Deering,
            S., Handley, M., Jacobson, V., Liu, C., Sharma, P., and L.
            Wei, "Protocol Independent Multicast-Sparse Mode (PIM-SM):
            Protocol Specification", RFC 2117, June 1997.

 [RFC2362]  Estrin, D., Farinacci, D., Helmy, A., Thaler, D., Deering,
            S., Handley, M., and V. Jacobson, "Protocol Independent
            Multicast-Sparse Mode (PIM-SM): Protocol Specification",
            RFC 2362, June 1998.

 [RFC3446]  Kim, D., Meyer, D., Kilmer, H., and D. Farinacci, "Anycast
            Rendevous Point (RP) mechanism using Protocol Independent
            Multicast (PIM) and Multicast Source Discovery Protocol
            (MSDP)", RFC 3446, January 2003.

 [RFC4601]  Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas,
            "Protocol Independent Multicast - Sparse Mode (PIM-SM):
            Protocol Specification (Revised)", RFC 4601, August 2006.

 [RFC4610]  Farinacci, D. and Y. Cai, "Anycast-RP Using Protocol
            Independent Multicast (PIM)", RFC 4610, August 2006.

 [RFC5796]  Atwood, W., Islam, S., and M. Siami, "Authentication and
            Confidentiality in Protocol Independent Multicast Sparse
            Mode (PIM-SM) Link-Local Messages", RFC 5796, March 2010.

Zheng, et al. Informational [Page 7] RFC 7063 Survey Report on PIM-SM December 2013

Appendix A. Questionnaire

 This section provides copies of the questionnaires exactly as
 distributed to operators and implementors.

A.1. PIM Survey for Operators

 Introduction:

 PIM-SM was first published as RFC2117 in 1997 and then again as
 RFC2362 in 1998.  The protocol was classified as Experimental in
 both of these documents.  The PIM-SM protocol specification was then
 rewritten in whole and advanced to Proposed Standard as RFC4601 in
 2006.  Considering the multiple independent implementations developed
 and the successful operational experience gained, the IETF has
 decided to advance the PIM-SM routing protocol to Draft Standard.
 This survey intends to provide supporting documentation to advance
 the Protocol Independent Multicast - Sparse Mode (PIM-SM) routing
 protocol from IETF Proposed Standard to Draft Standard.  (Due to
 RFC6410, now the intention is to progress it to Internet Standard.
 Draft Standard is no longer used.)

 This survey is issued on behalf of the IETF PIM Working Group.

 The responses will be collected by a neutral third-party and kept
 strictly confidential if requested in the response; only the final
 combined results will be published.  Tim Chown and Bill Atwood have
 agreed to anonymize the response to this Questionnaire.  They have a
 long experience with multicast but have no direct financial interest
 in this matter, nor ties to any of the vendors involved.  Tim is
 working at University of Southampton, UK, and he has been active in
 the IETF for many years, including the mboned working group, and he
 is a co-chair of the 6renum working group.  Bill is at Concordia
 University, Montreal, Canada, and he has been an active participant
 in the IETF pim working group for over ten years, especially in the
 area of security.

 Please send questionnaire responses addressed to them both.  The
 addresses are tjc@ecs.soton.ac.uk and william.atwood@concordia.ca.
 Please include the string "RFC4601 bis Questionnaire" in the subject
 field.

Zheng, et al. Informational [Page 8] RFC 7063 Survey Report on PIM-SM December 2013

 Before answering the questions, please complete the following
 background information.

 Name of the Respondent:

 Affiliation/Organization:

 Contact Email:

 Provide description of PIM deployment:

 Do you wish to keep the information provided confidential:

 Questions:

 1 Have you deployed PIM-SM in your network?

 2 How long have you had PIM-SM deployed in your network?  Do you know
   if your deployment is based on the most recent RFC4601?

 3 Have you deployed PIM-SM for IPv6 in your network?

 4 Are you using equipment with different (multi-vendor) PIM-SM
   implementations for your deployment?

 5 Have you encountered any inter-operability or backward-
   compatibility issues amongst differing implementations?  If yes,
   what are your concerns about these issues?

 6 Have you deployed both dense mode and sparse mode in your network?
   If yes, do you route between these modes using features such as
   *,*,RP or PMBR?

 7 To what extent have you deployed PIM functionality, like BSR, SSM,
   and Explicit Tracking?

 8 Which RP mapping mechanism do you use: Static, AutoRP, or BSR?

 9 How many RPs have you deployed in your network?

 10 If you use Anycast-RP, is it Anycast-RP using MSDP (RFC 3446) or
    Anycast-RP using PIM (RFC4610)?

 11 Do you have any other comments on PIM-SM deployment in your
    network?

Zheng, et al. Informational [Page 9] RFC 7063 Survey Report on PIM-SM December 2013

A.2. PIM Survey for Implementors

 Introduction:

 PIM-SM was first published as RFC2117 in 1997 and then again as
 RFC2362 in 1998.  The protocol was classified as Experimental in both
 of these documents.  The PIM-SM protocol specification was then
 rewritten in whole and advanced to Proposed Standard as RFC4601 in
 2006.  Considering the multiple independent implementations developed
 and the successful operational experience gained, the IETF has
 decided to advance the PIM-SM routing protocol to Draft Standard.
 This survey intends to provide supporting documentation to advance
 the Protocol Independent Multicast - Sparse Mode (PIM-SM) routing
 protocol from IETF Proposed Standard to Draft Standard.  (Due to
 RFC6410, now the intention is to progress it to Internet Standard.
 Draft Standard is no longer used.)

 This survey is issued on behalf of the IETF PIM Working Group.

 The responses will be collected by a neutral third-party and kept
 strictly confidential if requested in the response; only the final
 combined results will be published.  Tim Chown and Bill Atwood have
 agreed to anonymize the response to this Questionnaire.  They have a
 long experience with multicast but have no direct financial interest
 in this matter, nor ties to any of the vendors involved.  Tim is
 working at University of Southampton, UK, and he has been active in
 the IETF for many years, including the mboned working group, and he
 is a co-chair of the 6renum working group.  Bill is at Concordia
 University, Montreal, Canada, and he has been an active participant
 in the IETF pim working group for over ten years, especially in the
 area of security.

 Please send questionnaire responses addressed to them both.  The
 addresses are tjc@ecs.soton.ac.uk and william.atwood@concordia.ca.
 Please include the string "RFC 4601 bis Questionnaire" in the subject
 field.

Zheng, et al. Informational [Page 10] RFC 7063 Survey Report on PIM-SM December 2013

 Before answering the questions, please complete the following
 background information.

 Name of the Respondent:

 Affiliation/Organization:

 Contact Email:

 Provide description of PIM implementation:

 Do you wish to keep the information provided confidential:

 Questions:

 1 Have you implemented PIM-SM?

 2 Is the PIM-SM implementation based on RFC2362 or RFC4601?

 3 Have you implemented (*,*, RP) state of RFC4601?  What is the
   rationale behind implementing or omitting (*,*,RP)?

 4 Have you implemented the PMBR as specified in RFC4601 and RFC2715?
   What is the rationale behind implementing or omitting PMBR?

 5 Have you implemented other features and functions of RFC4601:

SSM

Join Suppression

Explicit tracking

Register mechanism

SPT switchover at last-hop router

Assert mechanism

Hashing of group to RP mappings

 6 Does your PIM-SM implementation support IPv6?

 7 Have you encountered any inter-operability issues with other PIM
   implementations in trials or in the field?

 8 Do you have any other comments or concerns about PIM-SM as
   specified in RFC4601?

Zheng, et al. Informational [Page 11] RFC 7063 Survey Report on PIM-SM December 2013

Authors' Addresses

 Lianshu Zheng
 Huawei Technologies
 China

 EMail: vero.zheng@huawei.com

 Zhaohui Zhang
 Juniper Networks
 USA

 EMail: zzhang@juniper.net

 Rishabh Parekh
 Cisco Systems
 USA

 EMail: riparekh@cisco.com

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