All buddies on macs, but can only vid chat with some

Question

I'm using panther and iChat2, they're all on tiger and iChat3. Just switched to BT homehub, before I was using speedtouch 330 also provided by BT. I can still vid chat to son in Alaska, but can no longer vid to son in London (who's also on BT). I can't vid chat with my ex in US. My ex can vid to Alaska, but not to London, London can vid to Alaska - but only occasionally. The problem is always user did not respond. We can all IM each other. I checked with BT and they say they're not blocking port 5060. I've read the technical stuff (and been daunted) but it seems that since all of us can vid chat with at least one other person the problem is unlikely to be the settings on the computers. Beyond that I'm baffled! Help please.
emac   Mac OS X (10.3.9)  

Answer 1

A question I have for you is what kind of connection are all these people on. A lot of times if I try to video chat to someone on tiger but they are connected wirelessly I'm able to connected sometimes but other times I cannot. They are located a block away from me, not accross an ocean. You may not be able to get a speedy enough connection to keep up with the demand. What are your uploads at these times? You also may want to try to set the Quicktime settings, goto sys prefs/quicktime/streaming/streaming speed. You want to set what you get from your ISP go no higher then 1.5mbps(dont use automatic)
In ichats prefs click on video and change bandwidth limit to NONE.
Restart iChat