Interfaces and Protocols

The Telecommunication system adopts the distributed network structure. Its functions are distributed among different physical entities. To accomplish a task, all devices must work together. All devices and subsystems are interconnected through interfaces based on specific protocols. In the communication system, the messages that are required to coordinate different entities are called signaling. The signaling system instructs every part of a system to work and coordinate together to accomplish tasks. Signaling messages are described in interface protocols and specifications. An interface refers to the connecting point between two adjacent network entities. A protocol defines rules to be complied with for exchanging information on the connecting point. Protocols are of the layer structure. The protocol of an interface is often described in the application layer.

Network Architecture:




Tables Below shows all interfaces its corresponding protocols used between different telecom entities.

Entities Connected	Interface Name	Signaling and Protocol
MSCe/MGW–BSC	A	BSAP
MSCe–VLR	B	Internal protocol
MSCe–HLR	C	MAP
VLR–HLR	D	MAP
MSCe–MGW	39/xx	H.248
MSCe–MSCe	zz	SIPI
MSCe–MC	Q	MAP
MSCe–SCP	T1	WIN
MSCe–SG	–	SIGTRAN