Hi,
For Video using Gmail (GoogleTalk IDs)
Yes both people have to be using iChat.
Google (Talk) is a Jabber server and the Web Browser Plug-in and the PC standalone App use a protocol called Jingle to Connect.
iChat uses a Process called SIP (Session Initiation Protocol)
The two are incompatible.
NOTE
Google's version of Jingle is not that compatible with other Jabber Applications versions either.
The Port.
The port can bee 443 or left at 5223 for a GoogleTalk Login in iChat.
The GoogleTalk server accepts both (This is pretty unusual for a Jabber server).
The SIP bit, the sending of the visible part of the Invite and the Video or Audio chat itself are on different ports to the Login.
iChat uses the same process and ports whether you are using a Google Talk Buddy List, another Jabber Buddy list or an AIM based login (AIM, @mac.com or MobleMe).
Although you can have Jabber Buddies from Google, Facebook or another Jabber server in a Jabber (or GoogleTalk) Buddy List you cannot have AIM based name in that Buddy list.
The same is true of a Buddy List that logs in to AIM. It can have a mixture of AIM, @mac.com and MobileMe but not Jabber based IDs including Google or Facebook ones.
Tech Support/ Screen Sharing.
Your parents would need a Mac, iChat account that is using the same service you do and to allow iChat through the router.
Linksys
These can be accessed in a Web Browser.
Where you would type Apple.com you type 192.168.1.1 (In the URL space)
This will bring up a password Dialogue box
The User ID is normally admin (in lower case)
The Password can be Blank (Just hit Enter) or it can also be admin depending on model.
Once you have access go to the Admisntration tab
In here, Enable UPnP. (This will allow the apps on the computer to tell the router which ports to open)
If you also have a tab called Security go there as well.
If this lists a Firewall as the top item Disable it (it has features that get in iChat's way)
Near the bottom is a line about Responding to Anonymous Requests.
Thios needs to be set so that th router does Respond (it's about responding to Pings and iChat sends a Ping during the Video or Audio Connection process.
10:36 PM Wednesday; September 14, 2011
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb( 10.6.8)
Mac OS X (10.6.8),
"Limit the Logs to the Bits above Binary Images." No, Seriously