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 an ITU-T H.248 MGC and media gateway (MG) to use the techniques defined by:

– simple session traversal utilities for NAT (STUN) reflexive address mapping as defined in [IETF RFC 3489] and [IETF RFC 5389];

– relayed address mapping using the traversal using relays around NAT (TURN) techniques as described in [IETF RFC 5766];

– comprehensive NAT traversal interactive connectivity establishment (ICE) techniques as described in [IETF RFC 5389].

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

Figure 1 summarizes the various packages as defined by the initial Recommendation. Every package is self-contained and does not use the extension principle.