The BGF supports up to eight concurrent virtual BGFs in a router. Each virtual BGF is connected to a gateway controller over its own PGCP connection. One virtual BGF can connect to one gateway controller at the same time. Multiple virtual BGFs can share a single service PIC. A single virtual BGF cannot span more than one service PIC or MS-DPC.
By creating multiple virtual BGFs, you can:
Figure 12 shows a topology with multiple virtual BGFs and gateway controllers. This topology enables one virtual BGF and one MultiServices PIC to continue handling gate requests and forwarding packets on open gates even when the other PIC fails.
Figure 12: Topology with Multiple Virtual BGFs and Gateway Controllers
You can have multiple gateway controllers configured for one virtual BGF. When a virtual BGF begins running on the router, it attempts to set up a connection to the first configured gateway controller. Each virtual BGF can have one active gateway controller and one or more standby gateway controllers. In case of a gateway controller failure or in case of the gateway controller sending instructions to the virtual BGF, the virtual BGF can switch to another gateway controller. Figure 13 shows an active and standby gateway controller connected to VBGF 2.
Figure 13: Active and Standby Gateway Controllers
If the PGCP connection between the virtual BGF and the gateway controller is lost, the virtual BGF attempts to reconnect to the gateway controller. If the virtual BGF cannot reconnect to the gateway controller, it traverses its list of gateway controllers until it successfully connects to one of the gateway controllers.
