The ITU-T Study Group 16 is working on multimedia security for H.323 mobility. One of the general problems addressed aims at enabling mobility in small and medium sized H.323-based corporate and enterprise networks.
The ITU Protocol H530 (6) is defined in [89] and [90]. (See http://www.itu.int/rec/recommendation.asp). In this protocol, a mobile H.323 user attaches at a foreign visited H.323 network domain in order to obtain H.323 services from the corresponding subscribed home domain; e.g. forwarded H.323 Voice-over-IP calls. The security issues of concern in such a scenario include mutual authentication of the mobile user and the visited domain, mutual authentication of the visited domain to the home domain and secure key agreement between the mobile user terminal and the visited gatekeeper.
Protocol H530 should provide Fresh Key Agreement and 3P-Authorization (G1-3,6,7,10,12).