Service Levels And Pvc Selection Criteria; Prerequisites For Frame Relay Pvc Selection - Cisco 10000 Series Configuration Manual

Frame Relay PVC Selection
Defaults
No PVC is defined.
Configuration Mode
Frame Relay VC-bundle configuration
Usage Guidelines for the pvc Command
To use this command, you must first create a Frame Relay PVC bundle and enter Frame Relay
VC-bundle configuration mode.
A PVC bundle must have at least one PVC for the bundle to come up. A PVC bundle cannot have more
than eight PVCs. If you try to configure more than eight PVCs in a bundle, the following message
appears on the console:
%FR vc-bundle contains 8 members. Cannot add another.
Dynamic PVCs can be specified as PVC bundle members; however, if a PVC has already been created
by using some other configuration command, you cannot add it to a PVC bundle. If you try to add it to
a bundle, the following message appears on the console:
%DLCI 200 is not a dynamic PVC. Cannot add to VC-Bundle.
If a PVC is already a member of a PVC bundle, any attempt to reuse that same PVC in a command that
creates a PVC (for example, frame-relay interface-dlci, frame-relay local-dlci) results in the
following error message:
%Command is inapplicable to vc-bundle PVCs.

Service Levels and PVC Selection Criteria

The DSCP and precedence bits classify the IP packet service levels. The Precedence field consists of the
first three bits of the ToS octet in the IPv4 header. You can use these bits to define a maximum of eight
service levels. When you use DSCP mapping, the DSCP octet replaces the ToS octet in the IPv4 header.
The first six bits are used to define a maximum of 64 service levels.
Using precedence-based or DSCP-based mapping, the router maps each IPv4 packet to a specific PVC
in the bundle, according to the value of the ToS or DSCP octet in the IP header. There is no special
treatment for broadcast or multicast and IP routing packets; the only differentiation in treatment is a
result of the ToS or DSCP octet settings.

Prerequisites for Frame Relay PVC Selection

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Cisco 10000 Series Router Quality of Service Configuration Guide
19-40
The Cisco 10000 series router must be running Cisco IOS Release 12.0(26)S or later releases.
To implement Frame Relay PVC bundles between two routers, you must enable IP Cisco Express
Forwarding (CEF) switching on the routers.
Chapter 19 Configuring Quality of Service for PVC Bundles
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