Re: IP -> PES -> MPEG TS?

["Kearney" <clausen@cosy.sbg.ac.at>]

----- Original Message -----
From: "TAKEI jun" <takei@csm.jcsat.co.jp>
To: <ip-dvb@erg.abdn.ac.uk>
Sent: Saturday, March 23, 2002 1:07 PM
Subject: Re: IP -> PES -> MPEG TS?
>
> PID has been designed as a PROGRAM IDENTIFIER in broadcasting
> world.
Yes - it identifies a broadcast channel; if you "tune" your receiver to this
PID you will receive all TS packets from the incoming TS multiplex of an
MCPC channel which have exactly this PID value. This corresponds largely to
a multicast group address on an Ethernet interface.

> MAC and IP address represent identification of the
> communication node.
note quite! the IP address is clearly the identification of a node or an end
system in a network, but the MAC level address is and identification of an
interface on a communications link. Unfortunately the Ethernet/Token Ring
LAN addresses are a combination of these two functions and this is largely
due to the fact that they use broadcast channels where an explicit routing
is not required. You can see the difference when you look at the "learning
bridges" and the binding of  IP addresses to e.g. ATM networks.

> If you map MAC address and PID, PID will be a MAC
> address. That means PID is not Program ID but Receiver ID and the
> number of receiver would be less than 8191. Do you think it is
> scalable?
>
correct. IP/DVB makes use of a broadcast channel, hence ther is no need for
a MAC level address. If you need one for authorization and authentication
then this is the concern of the return channel, not the forward channel. The
IP address is totally sufficient to address individual station of you really
need to.

Finally - satellite networks behave differently from LANs (two-way, very
short delay, cheap bandwidth) and, hence, transferring solutions from the
LAN world to MPEG2-S networks is not a reasonable approach.

--cls