Can Winsock connections randomly fail?

I have a blocking client/server connected locally via Winsock. The client uses firefox to retrieve data from websites, passing certain data along to the server for extra processing. The server always responds, and the processing can take anywhere from 1/10th second to a few minutes. The client has no winsock connection to anything but the server; all web data is retrieved to hard-drive via firefox.

This setup works quite well until, seemingly randomly, the client's recv returns -1 (SOCKET_ERROR) with error code 10054 (WSAECONNRESET). This means the server supposedly terminated connection, but the server is a开发者_C百科ctually still waiting to recv as if nothing is wrong. The connection has failed in this way as early as 5 minutes in or after working for as long as about an hour and a half. The client sends about 10 different types of requests to the server, and failure has occurred on a variety of them. The frequency of requests is roughly constant, probably an average of 10-15 a minute. When the connection breaks, neither computer experiences internet problems and remote desktop does not disconnect.

Initially I thought memory leaks, but after extensive debugging I am reasonably certain no more exist. Firefox is engaged in considerable HTTP traffic at times, so I thought maybe that could be filling available socket bufferspace or something -- seems doubtful but at this point I'm really not sure. So, could it be more memory leaks, maybe a hidden buffer overrun, too much web traffic? What is causing my Winsock app to randomly fail?

Sounds like a firewall at work.

Many firewalls are configured to terminate idle connections (i.e. open TCP sessions on which no data is transferred for awhile). Especially if it's an HTTP connection, which are typically not persistent.