Distributed Testing

I have a project set up on a server at my work where every night task scheduler runs my TC project which is set up for distributed testing and runs through a number of test items. The entire test run last abouts 4 hours or so.But recently it just stops at exactly 11:30pm. It gives the same error in the results log as if I had manually stopped it myself which is "The execution was interrupted  by the network suite". Any ideas as to what would cause this or if its even a test complete/execute problem?