[Asterisk-video] Videophone based network

[Neil Stratford]

Hi Joseph,

> I want to provide a full complete videophone network - so that 
> like in a typical office - you would see that every staff have their own 
> telephone. I want to provide the same for the BDA - using videophones - 
> so every staff would be able to call each other on the videophone with 
> ease. I'll also like to have a conference videocall for this as well.

Video calling works within asterisk today, albeit with some limitations. 
If you are all using the same video phone (and the same codec) then it 
should be able to provide this service for you without too much trouble.

The conferencing part can be provided by using app_videoswitch which 
allows a single switchable view per caller (but no mixing of video). You 
could also use this in your VRS implementation.

> The telephone to use can be something like the Grandstream GXV3000 IP 
> Videophone which is a SIP videophone using H264 video codec. Sound 
> obviously isn't important as we would be conversing in sign language 
> however since we do have hearing staff, they'll have a VoIP capacity as 
> well.

H.264 is only in the svn trunk version of asterisk, but hopefully the 
1.4 beta will be out soon...

> In each Regional Office - we have two ADSL lines which all are currently 
> getting upgraded to 8Mbs/800Kbs via BT Broadband Business (unlimited 
> bandwidth) - the 800Kbs upload probably means we could have at least 2 
> videocall going in/out of the office at any time - could Asterisk allow 
> me to limit the number of videocalls? (ideally we'll love to have SDSL, 
> but they cost too much)

You should be able to use the call-limit setting in the sip user 
definition to limit the number of calls, but there is the usual concern 
about contended bandwidth really giving you 800k. Another thing to watch 
out for today is packet re-ordering - if you see re-ordering on your 
network you may have problems due to the way asterisk re-generates 
sequence numbers.

> I'll like to link up all 6 Regional offices within a videophone network. 
> I'll be interested to hear from you folks if you think that's easily 
> done with Asterisk? With H.264 video codec (video quality is going to be 
> very important) and using either hardware-based or software based 
> videophone for the whole network (for the mobile users with laptop's, 
> they would use a software based such as the Vcon vPointHD which is 
> H323/SIP capable videophone software with H264 video codec so that they 
> can dial home)

Asterisk doesn't support any trans-coding between video codecs, so you 
would need to stick with one (probably H.264 from what you say). As it 
stands today I don't believe H323 video works out of the box, but I know 
that some people on this list have patches to make it work.

Neil

-- 
Neil Stratford - http://www.vipadia.com/ - sip:call at vipadia.com
Vipadia Limited :: VoIP Research and Development