SS7 Components

The SS7 signaling architecture consists of three essential components, interconnected via signaling links. 

Signal Switching Point (SSP)

-are switches that have SS7 software and terminating signaling links

-can originate, terminate, and switch calls

-use the calling number party info to determine how to route the call

-looks up the dialed digits in the SSP routing table to find the corresponding trunk circuit and terminating exchange

-then sends an SS7 message out to the adjacent exchange requesting a circuit connection on the trunk which was specified in the routing table

-manages all of those connections until the destination is reached

Signal Transfer Point (STP)

-are packet switches and act like routers in SS7 networks

-messages are not usually originated by an STP

-three levels of STP:

            -National: exists within the national network. It can transfer messages that use the
             same national standard of protocol.

-International: functions within an international network. It provides for SS7 interconnection of all countries, using the ITU-TS standard protocol.

-Gateway: converts signaling data from one protocol to another. Gateway STPs are often used as an access point to the international network.

Signal Control Point (SCP)

-is usually a computer used as front end to a database syatem

-is an interface to telco database