Can a WebService execute a LONG process?

[Garrek]

I need to expose a WebService that will take anywhere from two to six
hours to execute. A client must be able to connect to the WebService,
tell it to start and then disconnect. Meanwhile, the WebService
continues the process until completion.

I'm concerned the WS will cancel execution at some point due to a
Timeout (the system thinks it froze, etc) or because the client
disconnected.

How can I deal with this if the potential issue exists?

Thanks