Hello Jyothi – 19 Mar 2005
GT or Global Title is a general concept/method of routing .As its name suggests TITLE is a stream of digits attached in front of all Signal packets (call busy, called party number, ssn etcc.,) SO that they can be routed to correct destination. Roaming is just one application.,actuallt most of Switches are using GT for Internal Message Routing ,under the hood.
in simple Terms:
GT Translates to DPC + SSN;;
Dpc = dest.point code
SSN = sub system No.
DPC i guess u know.
SSN is general term that can broken into any system number : from MSC/VLr–>BSC–>BTS–>Subscriber no..
SO when One MSC wants to communnicate with other MSC, in a network of many interconnected MSCs it Routes it on the basis of a PREDEFINED DEDICATED GLOBAL TITLE ,prefixed with the actual signal Packet.
SO in the Gist GT can take any value from MSC/VLR Number to a simple Subscriber number.
I hope u find it useful
regards
Sandoshak