http://www.rfc-editor.org/rfc/rfc2052.txt
RFC 2052: A DNS RR for specifying the location of services (DNS SRV), A. Gulbrandsen, P. Vixie1996-10-01T23:00:00-00:00This document describes a DNS RR which specifies the location of the server(s) for a specific protocol and domain (like a more general form of MX). This memo defines an Experimental Protocol for the Internet community.