Stuck in preview/Invitation acceptance not working

Question

Hi Everybody -
I have searched pretty thoroughly, I think, and don't have an answer.  Thus, I am reviving the topic to see if there's new info on this.
Both parties using 10.7.5, iChat 6.0.2 and AIM accounts.
The problem, as stated in the title, is accepted invitations are not effective and both parties remain stuck in Preview.
I did search my /Library for iChat preferences (to delete them) and, to my surprise, was unable to find them.  Also, both parties have re-set P-RAM.
Any advice would be greatly appreciated.
Thanks!
Best wishes,
ed

Answer 1

HI,
You are sure you were in ~/Library/Preferences or Macintosh HD/Users/yourAccount/Library/Preferences to give it i's long path ?
It is also unlikely that deleting any of the .plists would help with this issue.
In the Connection Doctor (Video Menu) giving any hints about this ?
If the Video Chat window says Connecting with the spinning cogwheel icon  then the issue  is more about ports that the app uses.
An AIM Account logs in to the AIM servers on port 5190 or 443 depending on the version and whether you have changed this port in older iChat versions.
That info is held in the com.apple.ichat.plist
When a Video Invite is sent it goes out on port 5678.
The other end receives it on that port.
The Mac Firewall Block incoming stuff rather than outgoing stuff.
If the Buddy is not receiving the Invite then the Firewall and the ports allowed for the computer's IP  needs to be check in the router.
At the point the Visible Invite is accepted the app moves to port 16402 and uses the SIP (Session Initiation Protocol) to actually check, verify and make the connection.
SIP is also used by VoIP devices (Voice over IP)
Some add-on devices like a Vonage adapter can be placed on your LAN and will strip SIP data thinking it is for a Phone ignoring the Address info.
This is normally because the device is placed in-line between the router and the computer.
It is best if it is given it's Own Ethernet port on the router which resolves the IP addressing issue.
Some routers are also "SIP Aware".
These can have ports for phones and can allow the phone to be used with VoIP.
Thomson-Alcatel are one brand who are of concern in this area.
Technically SIP has internationally agreed ports (5060-5063)
It should use one of these ports and more on one if busy.
ISP and backbone Internet providers are not supposed to interrupt such data passing through their servers.
At one point some ISPs were blocking these ports and then charging extra money to have them opened.
(Many ISPs were telecom companies losing Money to these long distance telephone call alternatives).
This caused Skype and later Apple to move which port that used SIP on.
I have not seen a thread I would attribute this issue to for some time though.
If you Mac Firewall is ON then check it is allowing Signed Software and that Messages and IMAgent is in the list.
Check that if you used Port Forwarding in your router that the computer has the same IP you pointed the ports at.
It is actually better if you use UPnP as this allows Screen Sharing.
Remove any Vonage (Or any other VoIP) device.
Check any new router (or routing modem) is not blocking/filtering SIP.
7:36 pm      Sunday; December 8, 2013
  iMac 2.5Ghz 5i 2011 (Mavericks 10.9)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad