3Com 10014299 manual Overview, Configure Multilink Frame Relay FRF.16

254CHAPTER 17: CONFIGURING FRAME RELAY

Configure Multilink Frame Relay (FRF.16)

By default, no Frame Relay switched PVC is created.

After configuring the Frame Relay switched PVC, the user will enter the frame relay switch view to perform the operations of shutdown and undo shutdown on the switched PVC.

The differences between configuring a Frame Relay switched route and configuring a Frame Relay switched PVC are listed below:

1)A Frame Relay switched route can become valid only when it is configured on the two Frame Relay switched interfaces, whereas a Frame Relay switched PVC can become valid as soon as it is configured in system view for once.

2)After the Frame Relay switched PVC is configured, the user will enter the frame relay switch view. At this time, the user can perform the operations of shutdown and undo shutdown on the switched PVC. However, the user cannot do that on a Frame Relay switched route.

Overview

Multilink Frame Relay can bundle multiple low-rate Frame Relay links to form a Frame Relay with high rate and wide bandwidth. Multilink Frame Relay creates a virtual Frame Relay interface which contains multiple Frame Relay physical interfaces. In this way, the bandwidth of the virtual Frame Relay is equal to the sum of the bandwidth of each Frame Relay physical interface contained in the virtual Frame Relay interface.

The virtual Frame Relay interface is called “Bundle”, and the physical interfaces contained in the virtual interface is called “bundle link”. As for an actual physical layer, bundle link is equal to an analog data link layer, and bundle manages all the bundle links. As for data link layer, bundle is analog physical layer.

Figure 80 Illustration of the relationship between bundle and bundle links

Layer 3 Applications

Frame Relay Protocol

Bundle

Bundle Link	Bundle Link
Physical Interface Physical Interface
Bundle Link

Layer 3 Applications

Frame Relay Protocol

Bundle

	Bundle Link		Bundle Link
Physical Interface		Physical Interface

Bundle Link

Bundle

On the Router Routers, the virtual Frame Relay interface is called “MFR interface”. One MFR interface corresponds to one bundle, and one physical interface corresponds to a bundle ink. The management performed on the bundle and bundle link is actually the management to the MFR interface and the physical interface.

After the Frame Relay physical interface is bundle to an MFR interface, the network layer parameters and Frame Relay link layer parameters configured on it