Sockets

I run a web application that opens a socket using cURL and sends data to a payment gateway and then receives confirmations, etc... Sometimes, a visitor clicks multiple times and I have the program check to see if a transaction is already in process, and if so, it redirects them to a page where they can check to see whether the transaction has gone through. So now I have 1 thread/request going, doing the processing, and returning the data, and a second thread where the visitor can check to see if thread 1 has come back from processing or not. Normally, this works okay. SOMETIMES, thread 1 does not come back with data from the gateway, as if the connection had timed out. Sometimes the gateway has processed the transaction, and sometimes not. So I would like to know if there's a program or something that will allow me to either log socket communication, or to monitor the sockets, etc... Can anyone help me out with this? - Jonathan