FUNCTIONAL PLANE

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.
• The transport plane is further divided into three domains:
  • IP Transport Domain :
  • Interworking Domain;
  • Non-IP Access Domain

2. Call Control & Signaling Plane

• It controls the major elements of the VoIP network, especially in the Transport Plane.
• 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.
• Service & App Plane consists of devices like :
  • Application Servers and
  • Feature Servers.

4. Management Plane

It functions such as :

• Subscriber and service provisioning,
• Operational support,
• Billing and
• 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