1. Transport Plane
•Responsible transport of messages (call signaling, call and media setup, or media) across the VoIP network.
•Transport mechanism(s) for these messages based on any technology that satisfies the requirements for carrying these types of traffic.
•Provides access for signaling and media with external networks, or terminals to VoIP networks.
•Transport Plane devices and functions are controlled by Call Control & Signaling Plane.
2. Call Control & Signaling Plane
a.It controls the major elements of the VoIP network, especially in the Transport Plane.
b.Carry out call control based on signaling messages received from the Transport Plane, handle establishment and teardown of media connections across the VoIP network by controlling components in the Transport Plane.
3. Service & Application Plane
•Provides the control, logic and execution of one or more services or applications in a VoIP network.
•Control the flow of a call based on the service execution logic. They achieve this by communication with devices in the Call Control & Signaling Plane.
4. Management Plane
It functions such as :
•Subscriber and service provisioning,
•Other network management tasks are handled.
It can interact with any or all of the other three planes through industry standard (e.g. SNMP) or proprietary protocols and APIs.
1. Media Gateway Controller Funtion (MGC-F)
2. Call Agent Function (CA-F)
3. Interworking Function (IW-F)
4. Call Routing
5. Accounting Function
6. SIP Proxy Server Function
7. Signaling Gateway Function
8. AccessGateway Signaling Function
9. Application Server Function
10.Service Control Function
11.Media Gateway Function
12.Media Server Function