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4-28
Cisco AVVID Network Infrastructure Enterprise Quality of Service Design
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Chapter 4 QoS in an AVVID-Enabled Wide-Area Network
QoS Recommendations for Remote Branch Routers
Example 4-20 Combined Voice, Video and Data over ATM Links
interface ATM4/0
bandwidth 3000
no ip address
no atm ilmi-keepalive
!
interface ATM4/0.60 point-to-point
bandwidth 3000
ip address 10.210.60.1 255.255.255.252
pvc BRANCH#60 0/60
vbr-nrt 3000 3000
This command sets the high ATM AAL5 traffic contract.
tx-ring-limit 3
This command reduces the delay caused by the TX ring buffer
.
service-policy output WAN-EDGE
This command applies the MQC policy to the ATM PVC.
QoS Recommendations for Remote Branch Routers
This section contains information about using QoS in WAN remote branch routers. It covers the
following:
·
WAN Edges
·
Remote LAN Edge for Voice
·
Remote LAN Edge for Video
·
Remote LAN Edge for Data
·
Summary Configuration
WAN Edges
The WAN edges on the remote branch routers have the identical configurations as their WAN
aggregation link counterparts.
Remote LAN Edge for Voice
The remote branch LAN edges are responsible for restoring the DSCP-to-CoS mappings that were lost
when the Layer 2 media changed. This mapping is accomplished using Class-Based Marking, which is
CEF dependent.
In the following voice-only example, voice and voice-control traffic are mapped from their DSCP values
(EF and AF31 respectively) to their corresponding 802.1Q CoS values (5 and 3 respectively). The policy
is applied to both the voice VLAN and the data VLAN Fast-Ethernet sub-interfaces.
Note
Class-maps that have been defined for the WAN edge policies do not need to be redefined