Multicast Using Bit Index Explicit Replication (BIER)
RFC 8279
| Document | Type |
RFC - Proposed Standard
(November 2017; No errata)
Status changed by status-change-bier-core-to-proposed-standard
|
|
|---|---|---|---|
| Last updated | 2018-06-05 | ||
| Replaces | draft-wijnands-bier-architecture | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Greg Shepherd | ||
| Shepherd write-up | Show (last changed 2017-06-14) | ||
| IESG | IESG state | RFC 8279 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Alia Atlas | ||
| Send notices to | Greg Shepherd <gjshep@gmail.com> | ||
| IANA | IANA review state | IANA OK - No Actions Needed | |
| IANA action state | No IANA Actions | ||
Internet Engineering Task Force (IETF) IJ. Wijnands, Ed.
Request for Comments: 8279 Cisco Systems, Inc.
Category: Experimental E. Rosen, Ed.
ISSN: 2070-1721 Juniper Networks, Inc.
A. Dolganow
Nokia
T. Przygienda
Juniper Networks, Inc.
S. Aldrin
Google, Inc.
November 2017
Multicast Using Bit Index Explicit Replication (BIER)
Abstract
This document specifies a new architecture for the forwarding of
multicast data packets. It provides optimal forwarding of multicast
packets through a "multicast domain". However, it does not require a
protocol for explicitly building multicast distribution trees, nor
does it require intermediate nodes to maintain any per-flow state.
This architecture is known as "Bit Index Explicit Replication"
(BIER). When a multicast data packet enters the domain, the ingress
router determines the set of egress routers to which the packet needs
to be sent. The ingress router then encapsulates the packet in a
BIER header. The BIER header contains a bit string in which each bit
represents exactly one egress router in the domain; to forward the
packet to a given set of egress routers, the bits corresponding to
those routers are set in the BIER header. The procedures for
forwarding a packet based on its BIER header are specified in this
document. Elimination of the per-flow state and the explicit tree-
building protocols results in a considerable simplification.
Wijnands, et al. Experimental [Page 1]
RFC 8279 Multicast with BIER November 2017
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for examination, experimental implementation, and
evaluation.
This document defines an Experimental Protocol for the Internet
community. 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 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8279.
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
Provisions Relating to IETF Documents
(https://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.
Wijnands, et al. Experimental [Page 2]
RFC 8279 Multicast with BIER November 2017
Table of Contents
1. Introduction ....................................................4
2. The BFR Identifier and BFR-Prefix ...............................7
3. Encoding BFR Identifiers in BitStrings ..........................8
4. Layering .......................................................11
4.1. The Routing Underlay ......................................11
4.2. The BIER Layer ............................................12
4.3. The Multicast Flow Overlay ................................13
5. Advertising BFR-ids and BFR-Prefixes ...........................13
6. BIER Intra-Domain Forwarding Procedures ........................15
6.1. Overview ..................................................15
6.2. BFR Neighbors .............................................17
6.3. The Bit Index Routing Table ...............................18
6.4. The Bit Index Forwarding Table ............................19
6.5. The BIER Forwarding Procedure .............................20
6.6. Examples of BIER Forwarding ...............................23
6.6.1. Example 1 ..........................................23
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