Global title

SS7 protocol suite
SS7 protocols by OSI layer
ApplicationINAP, MAP, IS-41...
TCAP, CAP, ISUP, ...
NetworkMTP Level 3 + SCCP
Data linkMTP Level 2
PhysicalMTP Level 1

A global title (GT) is an address used in the SCCP protocol for routing signaling messages on telecommunications networks. In theory, a global title is a unique address which refers to only one destination, though in practice destinations can change over time.