I recently made a post about trying to configure our firewall to allow two companies to access a program on out network. From the help I recieved I was able to get everything working just fine, but now one of the companies has emailed me saying they have the following problem when trying to connect to our VPN...

error message: Error 721, the remote computer did not respond.

However when I test it with a laptop hooked up to a outside network it seems to connect just fine and I do not recieve this error. What could be causing this? Is it a problem on the companies end or am I missing something? I was also asked by the other company is the connection traverses their NAT, but I am unsure. The second company connects just fine and I haven't heard any problems with them.