Using IChat internationally from different locations?

I travel internationally on a very frequent basis, my reasoning for setting up IChat at home and with my laptop was to stay in touch with the family.

I am having difficulty at most of the "Hotel Connections" that I try to utilize. I am currently in Japan, I check my connection speed and more than meets the minimum by a large margin. The only other possibility that I can see may be the ports that the hotels firewall (if one installed) has open.

How can I identify the address for the network that I am using and check to see if the required ports are open? Also has anyone else been able to get a ISP provider to open these ports if they are found to be closed?

I use VOIP to call home all the time with no problems but if I cannot utilize the IChat it defeats the purpose of the purchase completely.

Thanks
Dave