I am developing a chat application in windows phone. I am using Matrix XMPP library for that. It worked fine using BOSH. Matrix has released a new version for windows phone which supports sockets. I tried connecting to XMPP using the new version. I tried with both BOSH and Sockets. But it is not working. But it didn't worked for me. I have to develop the application with sockets. I included the line xmppClient.Transport=Transport.Bosh; And tried with sockets also xmppClient.Transport=Transport.Sockets;