I try to get the Windows 7 (or Vista) remote assistance feature to work, without using UPnP on the novices computer.

After enabling Teredo on the expert's computer (that is in a corporate network, and therefore has teredo disabled by default), I tried to connect to the novice both using Easy Connect and the invitation file with no success.

My triubleshooting included the following (so far).

• A connection to the novice from my home pc was successful, hinting at a misconfiguration on the experts side.
• Both computers have a "qualified" connection to the Teredo Server.
• Both computers have a valid Teredo IP, access to the Global_ PNRP cloud and can resolve names registered with PNRP on the other computer.
• The expert can resolve the PNRP Id automatically generated with an Easy Connect help request
• Both computers can ping the other's PNRP name.
• Both computers can ping the other's Teredo IP Address using ping -6

Now, I am a little stumped. I expected Remote Assistance to work at this point, since my corporate firewall has no Teredo filtering. What could RA cause not to work in this setting?

Thanks in advance!