IChat gets choppy after 90 secs- Started after 10.4.10 update

Question

I've tried all of the above fixes including changing the bandwith anywhere from none to LAN as well as various combinations of the Quicktime streaming speeds. Nothing has been going well. Things have been the same since going to 10.4.10. We have Comcast and the download speed is 6 Mbs and the upload is 1.2 Mbs. I've tried it on our Macbook Pro 2.4 and Macbook Pro 2.0 with the same results. In addition, the FPS is always at about 15 fps. After 90 secs or so, the video becomes very choppy and the audio quality goes out. Interestingly, my parents (Mac mini) have no problems when they iChat with my brother (Macbook 1.8). This is getting pretty frustrating.

Answer 1

Hi Edsel Kim,
Do you know if this service is true VoIP ?
I could not see any further as the Learn More page wanted me to type my address in and Britain is not an area they cover.
It is about which ports iChat is using When.
iChat logs in to the AIM server on port 5190 by default and this can be changed anything but we suggested 443 as this is below 1024 and also used for secure mail applications.
This is ion the TCP protocol and allows you to Text chat.
If you want to Send files or Pics in the chat, iChat moves to the UDP Protocol and the Chat reads "Direct Chat"
iChat also uses UDP on port 5190 for Group chats.
And also your Buddy list - who is online and new Buddy pic and Status Messages.
For the A/v Side iChat uses different ports
The Visible invite you see in on Port 5678 on the UDP Protocol.
Then as ichat is a VoIP app it moves to port 5060 and contacts the SNATMAP server. This is an SIP/VoIP server that your iChat tells what ports it wants to use for the A/V chat from 16384-16403 (4 ports for a 1-1 vid chat)
This SIP process involves the SNATMAP server finding your Buddy over SIP and telling their iChat which ports.
It is effectively like an old fashioned telephone exchange with text based info passing back and forth until the call is successful then the server drops out and you are Peer to Peer (you can actually log the Buddy List off line now).
SIP is an International Standard and is always with ports 5060-5063. If the first is busy it moves up one until it finds a clear port of those 4.
Now other VoIP equipment like Vonage adapters can effect the passing of iChat SIP data.
AN ISP that offers a VoIP service can block the ports expecting extra fees for the service - although on the whole if they are told they are blocking an application they relent and open the ports.
So no. SIP is on port 5060 and can not be moved as it an International standard.
Find out if the ISP offer a VoIP service and see if they block the ports.
Any Vonage or similar adapter needs to taken out of being In-Line between the computer and modem and off a separate Ethernet port from a router (or routing modem).
10:34 PM Sunday; July 15, 2007