[linux-dvb] Re: MPE MAC broadcast

[Johannes Stezenbach <js@linuxtv.org>]

On Mon, Jan 31, 2005 at 04:39:25PM +0100, Evangelos Stergiou wrote:
> Well, either I don't understand, or I wasn't clear with this.
> 
> I transmit IP data with a MPE MAC broadcast enveloppe over satellite.

IMHO there is no such thing as a "MPE MAC broadcast envelope". The fact
that MPE MACs look like ethernet MACs does not mean that they're
the same thing.

> I cannot receive my IP data on my DVB-S card unless its MAC is 
> FF:FF:FF:FF:FF:FF
> or I put it on promisc mode. I mean "any data", not even those having 
> destination IP =
> my card's unicast IP.

MPE filtering works on MACs, not IP-Addresses. (Of course the IP-Address
must be correct also, otherwise the Linux IP stack will drop the packets).

> I am a satellite service provider. Suppose I have a park of a thousand 
> receiving sites (which I do have).
> My gateway encapsulates my IP data into a MPE MAC broadcast enveloppe (much 
> easier
> than having all my sites configured to the same MAC).

IMHO this is wrong. You must address packets with the correct MAC. I think
this is usually done by deriving the IP address from the cards MAC
(which your customers must tell you at registration time).

> Maybe ETSI EN 301 192 does not say anything about having to open a filter 
> for receiving MPE MAC
> broadcast, but I am pretty sure IETF IPDVB WG does. In any case, I 
> shouldn't have to be promisc
> to receive IP data addressed to me.

I haven't read the IETF IPDVB WG publications. If you have, then
point me to the docs which back up your position.

Johannes