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
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This Internet-Draft will expire on April 27, 2018.
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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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