Not able to telnet to server

Out of the blue for some odd reason I am no longer able to telnet to one of my SCO Unix servers. I can ping, ftp and do a traceroute to it, just cant telnet. When I attempt to telnet to it, I just get this

Trying ##.##.##.##....
telnet: Unable to connect to remote host: Connection timed out

What I don't understand is that other host within this office are able to telnet to this SCO server. Anything outside the subnet or remote sites are NOT able to telnet to this SCO machine. Could this be something internally with this server itself or could this have to do with some router settings being changed? Anyone have any suggestions??

Thanks
macastor

---------- Post updated at 11:15 AM ---------- Previous update was at 10:15 AM ----------

Problem solved! Turns out network provider made changes on their end. They disabled "telnet". Damm them!!