Assignment of precedence levels to PVC bundle members lets you create differentiated services, because you can distribute the IP precedence levels over the various PVC bundle members. You can map a single precedence level or a range of levels to each discrete PVC in the bundle, which enables PVCs in the bundle to carry packets marked with different precedence levels.
Use the precedence other command to indicate that a PVC can carry traffic marked with precedence levels not specifically configured for other PVCs. Only one PVC in the bundle can be configured using the precedence other command.
This command is available only when the match type for the PVC bundle is set to precedence by using the match precedence command in Frame Relay VC-bundle configuration mode.
You can overwrite the precedence level configuration on a PVC by reentering the precedence command with a new level value.
All precedence levels must be accounted for in the PVC bundle configuration, or the bundle will not come up. However, a PVC can be a bundle member without a precedence level associated with it. As long as all valid precedence levels are handled by other PVCs in the bundle, the bundle can come up, but the PVC that has no precedence level configured will not participate in it.
A precedence level can be configured on one PVC bundle member per bundle. If you configure the same precedence level on more than one PVC within a bundle, the following error appears on the console:
%Overlapping precedence levels
When you use the mpls ip command to enable multiprotocol label switching (MPLS) on the interface, MPLS and IP packets can flow across the interface, and PVC bundles that are configured for IP precedence mapping are converted to MPLS EXP mapping. The PVC bundle functionality remains the same with respect to priority levels, bumping, and so on, but the match precedence command is replaced by the match exp command, and each precedencecommand is replaced by the exp command. The result is that a bundle-member PVC previously configured to carry precedence level 1 IP traffic now carries EXP level 1 MPLS traffic.
When MPLS is disabled, the match precedence and match dscp commands are restored, and the exp commands are replaced by precedence commands.
When MPLS is enabled or disabled, PVC bundles configured for IP precedence mapping or MPLS EXP mapping will stay up, and traffic will be transmitted over the appropriate bundle-member PVCs.