Subject: I-D ACTION: draft-holbrook-ssm-00.txt

From: Bill Fenner <[email-masked]>
Date: Tue, 14 Mar 2000 12:01:25 -0800

Just to raise awareness about this relevant draft (particularly
Appendix I):

A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Source-Specific Multicast for IP
        Author(s)       : H. Holbrook, B. Cain
        Filename        : draft-holbrook-ssm-00.txt
        Pages           : 18
        Date            : 13-Mar-00
        
IP addresses in the 232/8 (232.0.0.0 to 232.255.255.255) range are
designated as source-specific multicast (SSM) destination addresses and
are reserved for use by source-specific applications and protocols
[IANA-ALLOCATION].  This document defines the semantics of source-
specific multicast addresses and specifies the policies governing their
use.  It defines an extension to the Internet network service that
applies to datagrams sent to SSM addresses and defines the host
extensions to support this service.

Appendix I of this document describes changes to the Internet Group
Management Protocol Version 3 (IGMPv3) [IGMPv3] to support source-
specific multicast.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-holbrook-ssm-00.txt

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From: Wilbert de Graaf <[email-masked]>
Date: Thu, 16 Mar 2000 11:55:05 -0800

Hugh, Brad,

I'm in doubt about  4.1, the remark about recvfrom(). I'm trying to think
why you would want to join a single socket to multiple group addresses. The
only reason to perform successive joins on a single socket for me has been
to join multiple interfaces, but not group addresses. I just wonder if it is
really necessary to perform demultiplexing on a socket in an application
using destination addresses.  Could somebody tell me about applications that
need this, or refer to an archived discussion about this ?

The first sentence in chapter 8, paragraph 2, ends with "even for an SSM
destination address G". I think you can strip that part since in the
beginning of the line you already narrowed down to SSM datagrams. And the
only SSM datagrams that come into another domain carry an SSM destination
address right ?

Regards, Wilbert