[mythtv-users] Way out idea on watching same thing inmultiplerooms

Gareth Glaccum gareth.glaccum at btopenworld.com
Wed Jan 6 22:07:30 UTC 2010


>----- Original Message ----- 
>From: David Brodbeck
>>On Jan 5, 2010, at 5:29 AM, Gareth Glaccum wrote:
>>Yup, I agree with that in principle. What about if they only have a 
>>100mb/s switch or hub though?
>>Don't get me wrong, I think unicast is the way forward at the moment.
>>However, I think that whatever is put in place, should be done with the 
>>idea that sometime in the future, multicast could be implemented /safely/ 
>>and an 'upgrade' to multicast should be >>coded in easily.
>That's reasonable...however, how far in the future are we talking?  100 
>mb/s is on its way out.  In fact, cutting-edge sites are already starting 
>to install 10 Gb, which means in another few >years it'll probably start 
>turning up in consumer gear.


I started implementing 10G networks into client sites over 4 years ago.
The problem with the multicast suggestion is not that the bandwidth is not 
there, it is the fact that most switches by default are not configured to 
correctly handle multicast packets (ignoring hubs which cannot perform 
multicast).
The problem is, that as standard, most switches do not decode/ perform 
multicast snooping. This means that they do not listen for multicast joins 
and leaves, and instead broadcast multicast communications to all ports.
This is a major waste of bandwidth.



More information about the mythtv-users mailing list