Hello all,
I found a site http://www.portforward.com/cports.htm that may prove to be of good use to GIT users. That particular section of the site shows many applications & games and the ports they use. That link will give you information about TCP/UDP ports to forward with GIT.
Another section of the site http://www.portforward.com/routers.htm shows instructions for port forwarding on a huge list of network equipment.
Yet more, http://firewalling.com/routers.htm, shows documentation for setting up firewalling.
I thought I'd post up this information here, due to seeing many posts from GIT users asking questions about connectivity & making games work.