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Internet Engineering Task Force (IETF)                          L. ZhengRequest for Comments: 7063                           Huawei TechnologiesCategory: Informational                                         Z. ZhangISSN: 2070-1721                                         Juniper Networks                                                               R. Parekh                                                           Cisco Systems                                                           December 2013Survey Report on Protocol Independent Multicast - Sparse Mode (PIM-SM)Implementations and DeploymentsAbstract   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; seeSection 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://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 toBCP 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 2013Table of Contents1. Motivation ......................................................31.1. Overview of PIM-SM .........................................31.2. Requirements of RFCs 2026 and 6410 .........................32. Survey on Implementations and Deployments .......................42.1. Methodology ................................................42.2. Operator Responses .........................................42.2.1. 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 ................................42.3. Vendor Responses ...........................................52.3.1. Implementations Based on RFCs 4601 and 2362 .........52.3.2. Lack of (*,*,RP) and PMBR Implementations ...........52.3.3. Implementations of Other Features ofRFC 4601 .......52.4. Key Findings ...............................................63. Security Considerations .........................................64. Acknowledgements ................................................65. References ......................................................65.1. Normative References .......................................65.2. Informative References .....................................7Appendix A. Questionnaire ..........................................8A.1. PIM Survey for Operators ....................................8A.2. PIM Survey for Implementors ................................10Zheng, et al.                 Informational                     [Page 2]

RFC 7063                 Survey Report on PIM-SM           December 20131.  Motivation1.1.  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 20132.  Survey on Implementations and Deployments2.1.  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 inAppendix 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.Zheng, et al.                 Informational                     [Page 4]

RFC 7063                 Survey Report on PIM-SM           December 2013   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 ofRFC 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 routerZheng, 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.  References5.1.  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 20135.2.  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 2013Appendix 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 asRFC2117 in 1997 and then again asRFC2362 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 asRFC4601 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 toRFC6410, 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 recentRFC4601?   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 2013A.2.  PIM Survey for Implementors   Introduction:   PIM-SM was first published asRFC2117 in 1997 and then again asRFC2362 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 asRFC4601 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 toRFC6410, 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 onRFC2362 orRFC4601?   3 Have you implemented (*,*, RP) state ofRFC4601?  What is the     rationale behind implementing or omitting (*,*,RP)?   4 Have you implemented the PMBR as specified inRFC4601 andRFC2715?     What is the rationale behind implementing or omitting PMBR?   5 Have you implemented other features and functions ofRFC4601:   - 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 inRFC4601?Zheng, et al.                 Informational                    [Page 11]

RFC 7063                 Survey Report on PIM-SM           December 2013Authors' 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.comZheng, et al.                 Informational                    [Page 12]