NetMeeting - Unable To Call VPN Users

[OUCATS]

Interesting Problem:
I have set up an ILS server to create a directory that NetMeeting users can see everyone who is logged on in our network. Currently the VPN users show up in this directory and can make calls using NetMeeting to our main office. But I can not make a call to the VPN users. It's like NetMeeting is trying to find them but can't. So I tried to find the VPN users computers on the network, but they don't appear. Is there any sort of backwards lookup I can enable to see the VPN users who are connected to the network because I believe if I can do this, then NetMeeting will work. I currently have a CISCO hardware based VPN.

Thanks

 

[Shift838]

Have you made sure IPSEC is open to both ways through the firewall and router?

 

[OUCATS]

OK, now the problem has changed a bit. I have one remote user that when he logs on to our network through the VPN, his computer appears in the Microsoft Network. So when I tried to call him using NetMeeting it worked with no problems. So what would cause one computer using a Cisco VPN to show up on the network and another computer using a Cisco VPN not to show up?? I know it has to be a setting, but I can't figure out which.