Re: Routing multicast streams

[Karsten Siebert <Karsten.Siebert@dataplanet.de>]

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You can do several things to route IP multicast to the LAN:

I added a little switch in /etc/mrouted.conf, which enables automatic PID
setting/removing. If a Windows machine wants to receive IP multicast it
initiates an IGMP message. Mrouted reads this and sents an UDP message to
dvbd, which then enables the PID. In case of FAZZT this is PID 1041 (I have
set the last two addresses of the IP multicast address to the PID for
simplicity 0x417=1041).

You can set the PID manually using /etc/dvbd.conf in the filter section.
Don't forget to set the routing entry: route add 224.0.0.0 netmask 240.0.0.0
on all your interfaces.

The problem with mrouted unfortunately is stability. It stops after a couple
of milion packets. You always can monitor multicasting in /proc/net/mr_...

As the PIDs are set anyway differently for downloads and streams, one could
avoid using mrouted and just switch from the dvb module to the appropriate
LAN module by changing the device structure of the allocated skbuff
structure if an IP multicast packets arrives via satellite. I do this by
setting fast forward in the kernel, changing the device structure if a
packet arrives before the net_if is issued. Now if the appropriate PID is
set, all packtes are transmitted directly to the output queue of the LAN
device (but always, even if there is no listener).


Karsten


----- Original Message -----
From: "Michael Wilson" <bananaski@redhotant.com>
To: <plesnik@inetbrno.cz>; "LinuxDVB" <linux-dvb@linuxtv.org>
Sent: Saturday, October 21, 2000 12:41 PM
Subject: Re: Routing multicast streams


> I have the same problem with my setup but I wish to route the FAZZT system
> which is on 224.224.4.17, all mrouted sees is 224.0.0.1, 224.0.0.2 and
> 224.0.0.4
>
> ----- Original Message -----
> From: Petr Plesnik <plesnik@inetbrno.cz>
> To: LinuxDVB <linux-dvb@linuxtv.org>
> Sent: Saturday, October 21, 2000 8:43 AM
> Subject: Routing multicast streams
>
>
> > Hello,
> >
> > a have problem with routing multicast streams. I have this
configuration:
> > Linux server with DVB card, dvb working ok. This server is connected
thru
> > eth0 to router (linux).
> > Router has 4 ethernet cards. One is connected to server with DVB, second
> is
> > connected to public internet,
> > and another two is two intranet LAN segments 10.2.2.x and 10.2.1.x. In
> > windows box on private lan for example my machine 10.2.2.10 I can use
> > sattelite connection thru squid on server. This working OK. But if I run
> > mrouted with standart config file on server machine and try to connect
to
> > europeonline for watching streaming TV, it does not work. Can anybody
help
> > me with setting mrouted, or need I setup router machine to?
> >
> >
> > Thanks for any help Peter
> >
> >
>