Subject: [Bier] I-D Action: draft-ietf-bier-mpls-encapsulation-01.txt

From: [email-masked]
Date: Fri, 05 Jun 2015 07:18:02 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.
 This draft is a work item of the Bit Indexed Explicit Replication Working Group of the IETF.

        Title           : Encapsulation for Bit Index Explicit Replication in MPLS Networks
        Authors         : IJsbrand Wijnands
                          Eric C. Rosen
                          Andrew Dolganow
                          Jeff Tantsura
                          Sam K Aldrin
	Filename        : draft-ietf-bier-mpls-encapsulation-01.txt
	Pages           : 15
	Date            : 2015-06-05

Abstract:
   Bit Index Explicit Replication (BIER) is an architecture that
   provides optimal multicast forwarding through a "multicast domain",
   without requiring intermediate routers to maintain any per-flow state
   or to engage in an explicit tree-building protocol.  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 bitstring 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 details of the encapsulation depend on the type
   of network used to realize the multicast domain.  This document
   specifies the BIER encapsulation to be used in an MPLS network.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-bier-mpls-encapsulation/

There's also a htmlized version available at:
https://tools.ietf.org/html/draft-ietf-bier-mpls-encapsulation-01

A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-bier-mpls-encapsulation-01

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

---

From: Eric C Rosen <[email-masked]>
Date: Fri, 5 Jun 2015 10:22:49 -0400

Draft-ietf-bier-mpls-encapsulation-01 make the following changes to the 
BIER encapsulation header:

- The first nibble is now 0x101, and is not to be used as a version field.

- The second nibble is now a four-bit version field.  The draft defines 
version 0.  Version 15 is reserved, and can be used for experimental 
purposes.

- The four-bit "proto" field (identifying the type of payload) has been 
moved to the last word of the header, immediately preceding the BFIR-id, 
and taking four bits of the 16 bits that had previously been reserved.

- A new proto value, "OAM" has been defined.

- The last word in the header now begins with two OAM bits, to be used 
for passive performance monitoring.  (This bits were formerly reserved.)

- There are now 10 reserved bits in the last word.

The draft now also requests an IANA registry for the "proto" field, and 
adds a few details on what to do if some of the header fields contain 
illegal values.

Please take a look and provide your comments.