Mac/Win Video Chat

I have been conducting regular text chat with a distant relative, who we shall call T.C., in China. Up to recently, I have been chatting away happily via iChat, with some AOL/AIM buddies. T.C. is an MSN user so I had to look around for an MSN-compatible Mac client. I came across Adium and have been quite happy with it, too - all my AIM buddies, and now this lone MSN user, and even any Yahoo! yakkers or ICQ friends I know, would be all listed in one window. Of course, I need to sign up with all the various services.
Alas, T.C. wants to try video chat so I go again for an MSN client. I settled for Mercury Messenger and thought I had to have a USB webcam. I borrowed one from my nephew and it did nothing for Mercury Messenger. Just out of curiosity, I plugged in my iSight camera and lo and behold there I was on the screen. I was able to send video over to T.C., half the world away, but unfortunately Mercury couldn't handle MSN Messenger 7.5's new video format. Not one to give up easily in the face of a technical hurdle, I searched briefly for any setting in Messenger 7.5 that may allow sending older video format - no dice. Next I tried another MSN client for the Mac, aMSN. This time I could see her, but she couldn't see me. On my side, I got some error message related to the fact that I was behind a router or a firewall. I went into my DSL router and mucked around with various settings and thought I found the relevant setting, but no confirmation from T.C. yet. The aMSN troubleshooting suggested making changes to something related to "port forwarding". Initially, I found no such settings, but then stumbled across the Services menu of the DSL config page. There were Services for pcAnywhere, VNC, and a bunch of other software that would require interaction between two computers. I added aMSN as a custom service with the port range as suggested by the Help doc. In the end, I wanted to put some setting back to the default but inadvertently locked myself out of the router. No Internet! Aaargh! Luckily, by pressing the Reset button on the back of the DSL router while it's powered on, I was able to get back in. Sure, everything was back to factory default, including admin name and password, all the MAC addresses I laboriously filtered in, but at least I'm back in the saddle again. Whew, talk about not leaving well enough alone...