Frame Relay PVC Selection
The Frame Relay PVC Bundles with QoS Support for IP and MPLS feature allows you to configure
multiple PVCs with different QoS characteristics between any pair of Frame Relay-connected routers
and to configure a group of Frame Relay PVCs with a single next-hop address. Packets are mapped to
specific PVCs in the bundle on the basis of the precedence level, differentiated services code point
(DSCP) level, or MPLS EXP level in the type of service (ToS) field of the IP header. Each packet is
treated differently according to the QoS configured for each PVC.
The Frame Relay PVC bundle management software provides flexible PVC management within a PVC
bundle by allowing traffic assigned to a failed PVC to be redirected to an alternate PVC within the
bundle. It also allows you to configure the bundle to go down when certain PVCs go down. IP packets
carrying different types of traffic can be transported on different PVCs within the same PVC bundle.
To determine which PVC in a bundle is used to forward a specific type of traffic, the Frame
Relay PVC bundle management software matches the IP precedence level, DSCP level, or MPLS EXP
level in the IPv4 header to a PVC configured with the same value. The bundle management software
sends the packet out on the PVC with the same value.
After you define a Frame Relay bundle and add PVCs to it, you can configure attributes and
characteristics to discrete PVC bundle members, or you can apply them collectively at the bundle level.
You can apply Frame Relay traffic shaping to each PVC within a bundle.
You can create differentiated service using PVC bundles by distributing IP precedence levels or DSCP
values over the various bundle members. You can map a single precedence level or DSCP value or a
range of precedence or DSCP levels to each PVC in the bundle. This enables you to either limit an
individual PVC to carry only packets marked with a specific precedence or DSCP level, or enable a PVC
to carry packets marked with different precedence or DSCP levels.
The bundle management software also allows you to configure how traffic is redirected if a PVC goes
down. If this occurs, the router attempts to identify an alternate PVC. If the router cannot locate an
alternate PVC, the router stops the PVC bundle.
The router forwards non-IP packets using the PVC that is responsible for carrying precedence level 6 or
DSCP level 63 traffic. The router uses process-switching to forward locally generated packets.
Feature History for Frame Relay PVC Selection
Cisco IOS Release
Release 12.0(26)S
Configuration Commands for Frame Relay PVC Selection
This section describes the following configuration commands:
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Cisco 10000 Series Router Quality of Service Configuration Guide
19-32
Description
The Frame Relay PVC Bundles with QoS Support for IP
and MPLS feature was introduced on the PRE1.
bump Command (Frame Relay VC-bundle-member), page 19-33
dscp Command (Frame Relay VC-bundle-member), page 19-34
exp Command, page 19-35
frame-relay vc-bundle Command, page 19-36
precedence Command (Frame Relay VC-bundle-member), page 19-37
protect Command (Frame Relay VC-bundle-member), page 19-38
pvc Command (Frame Relay VC-bundle), page 19-39
Chapter 19
Configuring Quality of Service for PVC Bundles
Required PRE
PRE1
OL-7433-09