The History of SS7

The History of SS7

 

The SS7 standard defines the procedures and protocol by which network elements in the PSTN exchange information over a digital signaling network to perform call setup, routing and control.
Throughout the years, different variants, or flavors, of SS7 have been developed. In fact, today there are more than 100 different variants of SS7 worldwide. Of course, differences in protocols are certainly not specific to SS7 networks, there are multiple IP-side protocols being developed as well, including SCTP, M3UA, SUA, MGCP, H.248, MEGACO, SIP and H.323.

Because of these different SS7 flavors, signaling networks in one geographic area may not be able to interwork with a signaling network in another. Protocol conversion between these two flavors is necessary for intelligent routing to occur. In VoIP applications, this would ideally occur in the same signaling gateway that allows SS7 to communicate to IP. The SEGway Signaling Gateway does exactly this.