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BIER WG                                                      Fangwei. Hu
Internet-Draft                                               Greg Mirsky
Intended status: Standards Track                         ZTE Corporation
Expires: April 27, 2018                                        Chang Liu
                                                            China Unicom
                                                        October 24, 2017


                                BIER BFD
                        draft-hu-bier-bfd-00.txt

Abstract

   Point to multipoint (P2MP) BFD is designed to verify multipoint
   connectivity.  This document specifies the support of P2MP BFD in
   BIER network.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on April 27, 2018.

Copyright Notice

   Copyright (c) 2017 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
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   described in the Simplified BSD License.



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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   2
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   2
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  BIER BFD Encapsulation  . . . . . . . . . . . . . . . . . . .   3
   4.  Bootstrapping BIER BFD  . . . . . . . . . . . . . . . . . . .   4
     4.1.  One-hop Bootstrapping . . . . . . . . . . . . . . . . . .   4
     4.2.  Multi-hop Bootstrapping . . . . . . . . . . . . . . . . .   4
   5.  Discriminators and Packet Demultiplexing  . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Bit Index Explicit Replication(BIER)[I-D.ietf-bier-architecture]
   provides optimal forwarding of multicast data packets through a
   multicast domain.  It does so without requiring any explicit tree-
   building protocol and without requiring intermediate nodes to
   maintain any per-flow state.

   [I-D.ietf-bfd-multipoint] defines a method of using Bidirectional
   Detection(BFD) to monitor and detect unicast failures between the
   sender (head) and one or more receivers (tails) in multipoint or
   multicast networks.

   This document describes the procedures for using such mode of BFD
   protocol to provide verification of multipoint or multicast
   connectivity between a multipoint sender (the "head", Bit-Forwarding
   Ingress Routers(BFIRs)) and a set of one or more multipoint receivers
   (the"tails", Bit-Forwarding Egress Routers(BFERs)).This document
   defines use of the point-to-multipoint BFD for BIER domain.

2.  Conventions used in this document

2.1.  Terminology

   This document uses the acronyms defined in
   [I-D.ietf-bier-architecture] along with the following:

   BFD: Bidirectional Forwarding Detection.




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   OAM: Operations, Administration, and Maintenance.

   P2MP: Point to Multi-Point.

2.2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  BIER BFD Encapsulation

   The BIER encapsulation is specified in section 2 of
   [I-D.ietf-bier-mpls-encapsulation].  The Proto field identifies the
   type of the payload.  If the proto field is 5,the payload is OAM
   packet.  [I-D.ietf-bier-mpls-encapsulation]does not provide
   definition for identification of an BIER OAM packet.  This document
   defines the format of BIER OAM packet.


       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | V | Msg Type  |     Flags     |          Length               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                    BIER OAM Control Packet                    ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


      V: two bits long field indicates the current version of the BIER
      OAM header.  The current value is 0.

      Msg Type - six bits long field identifies OAM protocol, e.g.  Echo
      Request/Reply or BFD.  If the Msg Type is BFD, the BIER OAM
      control packet is BIER BFD packet.

      Flags - eight bits long field carries bit flags that define
      optional capability.

      Length - two octets long field that is length of the BIER OAM
      control packet in octets.








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4.  Bootstrapping BIER BFD

4.1.  One-hop Bootstrapping

   The ISIS BFD-Enable TLV is defined in [RFC6213], which could be used
   for BIER BFD bootstrapping if the underlay routing protocol is ISIS
   routing protocol.  When the adjacency between BIER nodes reaches the
   2-Way state, ISIS Hellos will already have been exchanged.  If an
   BIER node supports BFD, it will have learned whether the other BIER
   node has BFD enabled by whether or not a BFD-Enabled TLV was included
   in its Hellos.  The BFD-Enable TLV format is defined in [RFC6213] and
   reused in this document.  The MT ID is the BIER multi-topology
   identify.  If the BIER node only supports single ISIS topology, the
   MT ID is zero.  NLPID is a Network Layer Protocol ID [RFC6328] and
   will be [TBD](IANA assigned, suggesting 0XC2) for BIER, but
   additional topology and protocol pairs could conceivably be listed.

4.2.  Multi-hop Bootstrapping

   The BIER OAM ping could be used for BIER BFD bootstrap.  The
   multipoint header sends the BIER OAM packet with Target SI-Bitstring
   TLV (section 3.3.2 of [I-D.ietf-bier-ping]) carrying the set of BFER
   information (Sub-domain-id, Set ID, BS Len, Bitstring) to the
   multipoint tails to bootstrap the BIER BFD sessions.

5.  Discriminators and Packet Demultiplexing

   The tail(BFER) demultiplexes incoming BFD packets based on a
   combination of the source address and My discriminator as specified
   in [I-D.ietf-bfd-multipoint].  The source address is BFIR-id and BIER
   MPLS Label(MPLS network) or BFIR-id and BIFT-id(Non-MPLS network)for
   BIER BFD.

6.  Security Considerations

7.  Acknowledgements

8.  IANA Considerations

   [ISO9577]defines one-octet network layer protocol identifiers that
   are commonly called NLPIDs and [RFC6328] defines the NLPID IANA
   consideration.  The code points 0xC0, 0xC1, 0xCC, 0xCF are assigned
   to TRILL, IEEE 802.1aq , IPv4 and PPP respectively [RFC6328].  It is
   requested for IANA to assign 0XC2 to NLPID for BIER in this document.







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                   +-------------+---------------------+
                   |  Code Point |         Use         |
                   +-------------+---------------------+
                   |     0xC0    |        TRILL        |
                   |     0xC1    |     IEEE 802.1aq    |
                   |     0xC2    | BIER[This Document] |
                   |     0xCC    |         IPv4        |
                   |     0xCF    |         PPP         |
                   +-------------+---------------------+

                                  Table 1

   IANA is requested to create new registry called "BIER OAM Message
   Type" and assign new type from the BIER OAM Message Type registry as
   follows:

               +--------+--------------+------------------+
               | Value  | Description  |    Reference     |
               +--------+--------------+------------------+
               |  TBD1  |   BIER BFD   | [this document]  |
               +--------+--------------+------------------+

                                  Table 2

9.  References

9.1.  Normative References

   [I-D.ietf-bfd-multipoint]
              Katz, D., Ward, D., and J. Networks, "BFD for Multipoint
              Networks", draft-ietf-bfd-multipoint-10 (work in
              progress), April 2017.

   [I-D.ietf-bier-architecture]
              Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
              S. Aldrin, "Multicast using Bit Index Explicit
              Replication", draft-ietf-bier-architecture-08 (work in
              progress), September 2017.

   [I-D.ietf-bier-mpls-encapsulation]
              Wijnands, I., Rosen, E., Dolganow, A., Tantsura, J.,
              Aldrin, S., and I. Meilik, "Encapsulation for Bit Index
              Explicit Replication in MPLS and non-MPLS Networks",
              draft-ietf-bier-mpls-encapsulation-10 (work in progress),
              October 2017.






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   [I-D.ietf-bier-ping]
              Kumar, N., Pignataro, C., Akiya, N., Zheng, L., Chen, M.,
              and G. Mirsky, "BIER Ping and Trace", draft-ietf-bier-
              ping-02 (work in progress), July 2017.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC6213]  Hopps, C. and L. Ginsberg, "IS-IS BFD-Enabled TLV",
              RFC 6213, DOI 10.17487/RFC6213, April 2011,
              <https://www.rfc-editor.org/info/rfc6213>.

   [RFC6328]  Eastlake 3rd, D., "IANA Considerations for Network Layer
              Protocol Identifiers", BCP 164, RFC 6328,
              DOI 10.17487/RFC6328, July 2011,
              <https://www.rfc-editor.org/info/rfc6328>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

9.2.  Informative References

   [ISO9577]  ISO/IEC TR 9577:1999,, "International Organization for
              Standardization "Information technology -
              Telecommunications and Information exchange between
              systems - Protocol identification in the network layer"",
              1999.

Authors' Addresses

   Fangwei Hu
   ZTE Corporation
   No.889 Bibo Rd
   Shanghai  201203
   China

   Phone: +86 21 68896273
   Email: hu.fangwei@zte.com.cn


   Greg Mirsky
   ZTE Corporation
   USA

   Email: gregimirsky@gmail.com



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   Chang Liu
   China Unicom
   No.9 Shouti Nanlu
   Beijing   100048
   China

   Phone: +86-010-68799999-7294
   Email: liuc131@chinaunicom.cn











































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