In playing with video between my N800 and my laptop using SIP I found that I needed to have H263 and H263+ enabled on my Asterisk box; for some reason having just one or other resulted in a no-go. Now, I understand that Asterisk has some codec negotiation problems (i.e. half the time it doesn't negotiate at all between clients that really don't like each other), but it seemed to work when I had both on. I also had to make sure that I had video over sip support enabled in the Asterisk config.

One other strange problem that I've run into though is that while I can see the video from the NiT camera on the laptop, the video from the laptop doesn't display on the NiT... there's some funky colours and dancing pixels where the video should be, so I know it's trying, but there's no actual picture for some reason; I don't have a different web cam to try unfortunately, so it could just be that the laptop is squirly some how...