All things related to multicast

[Tim Chown <>]

On Mon, Apr 07, 2008 at 01:31:28AM +0900, Hitoshi Asaeda wrote:
> > > 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

-- 
Tim