Remote desktop connection problem

Hi,

I’m an administrator in Sri Lanka. We have 3 sites (Colombo(Head Office), Wattala, Mabima). Colombo connects to Malaysia through the international link. When an international user tries to connect to our server which risides in colombo through the international link, he can connect without any problem. When he tries to connect to a server which resides in Wattala site, he gets the following error message. He can tracert to the computer though. What could be the possible reason for this error message?

Error Message: This computer can’t connect to the remote computer. Try connecting again. If the problem continues, contact the owner of the remote computer or your network administrator.