ITU-T H.248.50 PDF

This Recommendation describes packages to enable various Network Address Translator (NAT) Traversal techniques to be employed in order to facilitate media flow between networks. The Media Gateway Controller (MGC) may utilize any of the packages in any order to gather addresses, map them and then maintain connectivity with and through NATs.

The packages described in this Recommendation allow a H.248 MGC and Media Gateway (MG) to use the techniques defined by:

− Simple STUN reflexive address mapping as defined in [IETF RFC 3489] and [IETF RFC 5389].

− Reflected mapping address mapping using the TURN techniques as described in [IETF RFC 5766].

− Comprehensive NAT traversal ICE techniques as described in [IETF RFC 5389].

In order to maintain backwards compatibility packages have been produced for both STUN as defined by [IETF RFC 3489] and those defined by [IETF RFC 5389].

Throughout this Recommendation it is assumed that the media gateway performs STUN server discovery through the use of Domain Name System (DNS) lookup.