BGF VoIP Solution Architecture
This topic describes BGF architecture and its components.
BGF Architecture Diagram
As shown in Figure 1, the two main components of the voice solution are the BGF and the gateway controller. The BGF and the gateway controller communicate over the Packet Gateway Control Protocol (PGCP).
Figure 1: BGF Voice Solution Architecture
Gateway Controller
In the BGF VoIP solution, the gateway controller is an external device that controls the BGF on the router. The gateway controller requests media services and resource allocation from the BGF, and it uses those services and resources for VoIP call signaling setup. The gateway controller maintains awareness and control over the network’s transport resource using PGCP connections with all of the BGFs in the network.
BGF
The BGF feature on the router provides Interconnect-BGF transport services for VoIP sessions. The BGF feature consists of:
- Virtual BGFs.
- A pgcpd process that controls the virtual BGFs.
- A data PIC that controls voice traffic based on instructions it receives from the virtual BGFs. You can use MultiServices PICs or MS-DPCs as the data PIC.
- An optional control PIC. You can run the virtual BGFs with the pgcpd process on either the Routing Engine or on one or more PICs. If you run your virtual BGFs on control services PICs, you can use MultiServices PICs or MS-DPCs. The MultiServices 500 PIC is not supported as the control PIC.
You can run up to eight concurrent virtual BGFs on a control services PIC in a router. You can use up to four control services PICs, allowing you to scale up to a maximum of 32 concurrent virtual BGFs. All virtual BGFs on a router must run in either the Routing Engine or on services PICs. You cannot run some virtual BGFs on the Routing Engine and some on services PICs. When you choose the Routing Engine to run virtual BGFs, you are limited to a maximum of eight concurrent virtual BGFs.
PGCP
The BGF and the gateway controller communicate over a Packet Gateway Control Protocol (PGCP) connection. PGCP is an H.248 v3 protocol with Juniper Networks extensions. PGCP complies with Gateway control protocol v3, ITU-T Recommendation H.248.1, September 2005 and with H.248 Profile for controlling Border Gateway Functions, ETSI Standard ES 283 018 V1.1.4, October 2007.
