Page 82 - eBOOK FUNDAMENTAL OF TELECOMMUNICATION NETWORK

Functions of each layer:

Layer Function

Derived from TUP to support ISDN and intelligent

networking functions. Widely replace the TUP in the
ISUP
most of PSTN network. Link between mobile network

and PSTN network.

This protocol is used for communication between SCP

nodes through STP nodes. Since SCP represents

TCAP databases, the TCAP is mainly used to
access databases. The end-to-end of transmission of

TCAP messages is performed by using the SCCP

SCCP provides end-to-end routing; by enabling TCAP

messages to the proper database. MTP layers

SCCP enables the transfer of signaling messages
between signaling points while SCCP enables end-to-

end transmission of signaling messages

70