Communications networks connect terminal equipment by using nodes. The nodes have to
exchange signaling information in order to control the setup of connections.
The signaling link can be viewed as a tunnel which connects two exchanges and accepts and conveys all signaling information.
Signaling information transfer is made possible by sending messages. A message is an information block whose structure and meaning of the single elements in the block are defined by specifications.
Components of a Signaling Network
- signaling end points (SEP)
- signaling transfer points (STP)
- signaling relay points
Signaling End Points (SEP)
These are the source and destination of signaling traffic. Can be identified as switching elements
Signaling Transfer Points (STP)
Based on destination the signaling transfer point (STP) forward the received signaling message to another STP or to a signaling end point
Signaling Relay Points (SRP)
Received signaling message are relayed by the transport layer called Signaling Connection Control Part (SCCP) where the destination address is determined by “Global Title Translation”. Messages are not processed by the signaling relay point. It is basically an STP that use global title translation to route message.
All signaling points are identified by a Signaling Point Code (SPC) which is identified by a numbering scheme defined in the standards
- associated signaling mode
- quasi-associated signaling mode