All things related to multicast

[Marc Manthey <>]

or how could the client join session if they are behind a NAT ? Are the tunneled via "http" ?

CR only provides a session announcement function. It does not invoke

IGMP/MLD join/leave and does not control routing functions.

Ah, did you ask how a multicast client application behind NAT can join

multicast sessions in general (not via CR)?

Ideally, NAT box must forward the client's IGMP/MLD messages. In that

case, If NAT can enable the function of IGMP/MLD proxy, it forwards

the downstream IGMP/MLD messages to its upstream router.

If NAT does not have the proxy function, then the application should

use AMT to bypass the NAT by establishing unicast UDP tunnel. AMT

suports to forward both multicast data and IGMP/MLD messages. One big

problem here is that AMT must be supported by both client hosts and

upstream routers (whether it's adjacent or not) and we need to break

its deployement barrier and operational or management difficulties.

Sorry joined the discussion late, maybe someone has already mentioned
the new RFC on multicast and NATs, RFC5135:

http://tools.ietf.org/rfc/rfc5135.txt

thanks for the paper tim,

isnt it  possible to to tunne lGMP/MLD packets over http ?

regards

marc

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