iChat "Communication Error"

[pinkrondo55]

My sister in law and I have been trying to video conference in iChat but keep getting a "Communication error" sometimes it also suggests one party is not responding when we are.

I video conference regularly with others so its not my Mac. She can video conference with us on other networks so it seems to be down to her
Siemens Speedstream 4200 router.

Does anyone know how to fix this issue???

 

[Satcomer]

Looks like on those networks she is running into firewall issues. This Apple document talks about using iChat with firewalls. I hope this helps.