Keep getting error message when trying to initiate chat with another mac

Question

Hi,
My brother and I are trying to have a video chat between our 2 macs. His is a brand new imac, purchased this week. Mine is a 2006 macbook pro. I have an AIM account and he has both an AIM account and a .mac account. Everytime we try to talk we get a communication error. I will paste some of the details below. I have video chatted with another friend who has an imac with no problems at all (although this was several months ago).
Here is a portion of the lengthy error details:
Thanks Scott
Date/Time: 2007-09-26 19:35:24.528 -0400
OS Version: 10.4.10 (Build 8R2218)
Report Version: 4
iChat Connection Log:
AVChat started with ID 3193720808.
0xe407860: State change from AVChatNoState to AVChatStateWaiting.
rustymacklin12: State change from AVChatNoState to AVChatStateInvited.
0xe407860: State change from AVChatStateWaiting to AVChatStateConnecting.
rustymacklin12: State change from AVChatStateInvited to AVChatStateConnecting.
0xe407860: State change from AVChatStateConnecting to AVChatStateEnded.
Chat ended with error -8
rustymacklin12: State change from AVChatStateConnecting to AVChatStateEnded.
Chat ended with error -8
Video Conference Error Report:
@:0 type=4 (00000000/22)
[VCSIP_INVITEERROR]
[19]
@SIP/SIP.c:2448 type=4 (900A0015/22)
[SIPConnectIPPort failed]
@SIP/SIP.c:2448 type=4 (900A0015/22)
[SIPConnectIPPort failed]
@SIP/SIP.c:2448 type=4 (900A0015/22)
[SIPConnectIPPort failed]
Message was edited by: Rusty68

Answer 1

Hi Rusty,
Error 8 has always been there since iChat 2.x (Although it is not until the error logs pop was introduced to 10.4.7 that it actually had a name for us users).
As to whose fault it is, is many and varied.
As the Article you link to says iChat uses the SIP (Session Initiation Protocol) as Apple has said iChat is a VoIP app and all VoIP use SIP.
Not all modem and router manufacturers handle SIP or VoIP properly all the time. Some go as far as making it always use one port instead of the SIP Standards 4 ports (It will use of the 4)
As AIM (application or the servers) do not use SIP it can not be AIM's fault.
Not all modem and Router manufacturers do NAT the same way further adding to the problem.
Lastly if it was working and now does not the also look carefully at what your ISP is doing.
Many are now trying to set up VoIP services. For this they try charging for thus service. One way is to block the SIP ports until the end user pays. In effect changing your Internet service in some cases without telling you.
Remember that if set Port Forwarding and kept your Modem or router doing DHCP then the IP your computer gets from that DHCP server could also have changed.
If a Home network (LAN) is set out in a linear fashion even if NAT is used then iChat will work.
This means if your Modem and router can not do UPnP and have to use a NAT based method like Port Forwarding then you have to set up a Static route from modem to Router and possibly router to computer and not have overlapping subnets caused by two DHCP servers.
MOdem with Static routing <-> ROuter in bridge or Static <-> computer
Not modem doing DHCP
Router doing DHCP
giving a computer two IPs
I have shown it this way to demonstrate more visually the overlapping.
Yes, it is fair to say that iChat has trouble with NAT, but it is mostly about how the LAN is set up, which can include using Wireless and Ethernet at the same time. IT is also true that many on-line games will have the same trouble.
Yes, Apple also run the SIP server that iChat connects to which handles ALL A/V chats and it could lose contact with the AIM servers or the AIM servers with it and lose the ability to contact the AIM screen names.
So in summary.
Could be your LAN and any setting (Except UPnP) used with a DHCP server.
Could be your ISP changing your Internet Service for their VoIP service.
Partly it is Apple for choosing the International SIP Standard
Partly it is due to the myriad ways modem and router manufacturers construct their firmware.
More specifically;
Without you "changing Anything" it can be your OWN DHCP server.
IT could be your ISP.
We have yet to touched on features on modems and routers that see the amount of Data iChat can send as an Attack on your connection and end the chat.
9:11 PM Sunday; September 30, 2007