For 3G systems it is a clear goal to be able to protect inter-network SS7 signalling protocols. The protection is done by security gateways which are located at the network border. As a consequence intra network SS7 signalling is not protected and network elements other than Security Gateways are not impacted.
This TS provides functional description of the SS7 Security Gateway. The document covers also network
architecture, routeing considerations, and protocol details.