Share screen not working

Question

I have OS 10.5.1. So does my colleague. I have an iMac with a camera. He has an iMac without a camera. He has DSL (1.5 mbps), while I have cable modem (16 mbps).
From everything I have read about iChat, he should still be able to share his screen with me.
We can easily get an audio session going, but, whenever we try to initiate a sharing session to share his screen, we get messages saying it is starting up, but then nothing ever appears. Is the DSL line too slow? Are we being impatient to expect the sharing to start within a minute? Is his color setting too high? (We have tried to reduce it to Thousands with no success.)
What is wrong? What else should we try?

Answer 1

Hi,
Apple have posted the ports iChat 3 uses.
http://docs.info.apple.com/article.html?artnum=93208
They have also published the Leopard ones (Without saying the Bonjour, Jabber and Login one are still needed)
http://docs.info.apple.com/article.html?artnum=306688
The Later article also says nothing about which ports the Screen sharing is done on.
Reading other pieces of information you learn that the Screen Sharing is based on Apple Remote Desktop.
In fact if in System Preferences > Sharing this is turned on you can not Screen Share from the Finder.
This table lists ports for that
http://docs.info.apple.com/article.html?artnum=106439
Namely port 5900 and 5988.
However I run Little Snitch, an app/utility that will tell me the ports iChat is using at any one stage and to what IP.
In iChat Screen sharing I have seen ports all over the place and not restricted to the one I have pointed as being listed.
I use UPnP in my routing modem and this seems to cope with this.
The Settings for Displays and the Speeds in this case are immaterial.
Audio chats normally use about 20k or so on my Mac
Screen sharing is about 48k (Probably just above what a dial-up modem might throughput) so both your speeds are good enough.
I have not seen excessive speed be a problem here as it can be with certain Video chats as there is less data to buffer.
10:55 PM Saturday; February 2, 2008