Patent ID: 7343497

Claim:
A method of facilitating the interworking of network elements of one or more communication networks, some of which network elements support a given security mechanism and others of which do not, the method comprising: at each network element which does support the security mechanism, maintaining a database listing peer network elements and an indication of whether or not the peer network elements support the security mechanism; before or upon initiation of a signalling communication from a peer network element supporting the security mechanism to another peer network element, inspecting the database of the initiating network element to determine whether or not the peer network element supports the security mechanism, and conducting the communication accordingly; and dynamically updating the databases stored at network elements based upon signalling information received from peer network elements, wherein use of the security mechanism for securing communications between elements is ensured when the mechanism is available, wherein each communication network is a public land mobile network, wherein if the peer network element is determined not to support the security mechanism, then the network element supporting the security mechanism does not attempt to negotiate a security association with the peer network element, and wherein the step of dynamically updating a database stored at the network element supporting the security mechanism includes removing an entry from the database, where the entry indicates that the peer network element does not support the security mechanism, after some predefined time has elapsed since the network element last communicated with the peer network element corresponding to the entry.