Subject: Re: [MBONED] Multicast Transition Overview

From: Stig Venaas <[email-masked]>
Date: Tue, 03 Jan 2012 10:48:16 -0800

On 12/31/2011 3:08 AM, Simon Leinen wrote:
> Antonio Querubin writes:
>> On Thu, 29 Dec 2011, Ronald Bonica wrote:
>>> It appears that the transition mechanism will have to support ASM
>>> because many IPTV receivers don't support IGMPv3. However, it will
>>> also need to support SSM because:
>
>> And global scalability of ASM isn't really supported in IPv6.  IPv6
>> multicast uses Embedded RP.
>
> Did you mean to say "[...] isn't really supported in IPv4.  IPv6 [...]"?
> To me, Embedded RP seems more scalable than what we have in IPv4 (MSDP).

Agree.

Depending on the location of RPs, from a PIM perspective it could be
sufficient to support translation of (S,G)-j/p (which would take care
of both ASM and SSM then), but I don't see any difficulties with
supporting ASM vs just SSM really.

The only ASM consideration, which I've been describing before, is that
it may be necessary or advantageous (depending on scenario or direction)
for the translator to be an RP or use MSDP to have knowledge of sources.

All this is obviously related to PIM, and perhaps only necessary when
translating between IPv4 PIM and IPv6 PIM.

For a translator that on one side speaks IGMP/MLD (irrespective of
whether the other side is IGMP/MLD or PIM), I think one can basically
just translate to/from IGMP/MLD.

Tina, I saw your message and will try to contribute. Been on PTO since
24th though, and now need to catch up.

Stig