[Sumover-tech] VIC and the number if possible participants

[Douglas Kosovic]

Hi Marc,

> while i was reading the vic man pages , 
> <https://frostie.cs.ucl.ac.uk/nets/mmedia/wiki/VicMan>
>
>  i have several questions :
>
> Is  <,./vic somehost/someport>  the host adress you specify in this 
> command a unicast or multicast adress and could it be ipv6 adress aswell ?

It can be either unicast or multicast. If the vic executable was built with 
IPv6 support, then it can be IPv6 also.

> and is there another "programm " ( like the reflector i was asking you to 
> connect to) or script needed to initiate a conference with more then 2 
> participants ?

For multicast, no other program is required, but each of the sites will need 
to be multicast capable and have multicast working between them. But if you 
need audio as well, RAT would typically also be used..

The AccessGrid toolkit (which uses vic and rat) uses a unicast bridge to 
allow multiple unicast sites to connect and also provide a bridge between 
multicast and unicast. There are about 30 bridges registered with the 
AccessGrid bridge repository.

> Is the number of participants that could join a conference "limited" ?

It's mainly limited by bandwidth and the number of connections a unicast 
bridge can cope with before starting to bog down performance wise. If you 
enter the AccessGrid3 ANL lobby, you'll often see lots of video streams, 
last time I looked there were about 20.

Access Grid 3.1 beta1 can be downloaded from:
   http://www.accessgrid.org/software
and it comes bundled with UCL vic and rat from the SUMOVER SVN repository.


Cheers,
Doug