Sockets and SOAP

Hi, I want to implement a client-server relationship between a PHP server application and another .NET client application. I want the connection to be kept alive, so I use the socket routine running till disconnecting. I also want to transfer the data between the server and client using SOAP envelopes. How can I send SOAP envelopes (requests & responses) through the same socket? If it's not possible with PHP's SOAP library, is it possible with other SOAP library for PHP (such PEAR:SOAP)? -thanks, Eli