I need a protocol to encapsulate and transmit information using XML documents

Hello,

I have to find a standard protocol to transmit some information embedded into a XML document.

The idea is that I have some files like a VoIp conversation or a email and I want to send this information through "sockets" (C++ programmation) in a XML document.

do you know some protocol to do this?

I know these sites to find protocols with this characteristics but I don't know how to find it:
ieeexplore.ieee.org, Google Scholar or RFCs.

Thank you very much!!

You mean, like SOAP? Or REST?