EIGRP unequal cost paths with CBWFQ/LLQ

[r.cheung]

We're planning to implement basic QOS for VoIP with CBWFQ/LLQ, and wanted to see if unequal cost load balancing would end up affecting the voice quality.

Also, since the volume of packets will traverse the different paths disproportionally, the bandwidth to reserve with the policy-map, for each interface, is unclear. I guess we'll have to determine what the ratios are in the proportion, or look to tag the voice traffic with a DSCP and policy route it through a specific interface.

[ciscomoderator]

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If anyone else in the forum has some advice, please reply to this thread.

Thank you for posting.

[wheeler.r]

You should determine what the voice bandwidth requirements are for your call volume. Your class-map should look something like:

class-map voice-class

match ip dscp 40

This will classify your voice traffic

Next create a policy-map

policy-map atm1/0-policy

class class-voice

priority 250

police 250 conform-action transmit exceed-action drop

class class-default

This will create a 250K llq for your voice traffic.

policy-map atm2/0-policy

class class-voice

priority 450

police 450 conform-action transmit exceed-action drop

class class-default

This will create a 450k llq for your voice traffic

Next, apply the policies to your interfaces.

interface atm1/0.1

pvc 1/45

service-policy output atm1/0-policy

!

interface atm2/0.1

pvc 3/45

service-policy output atm2/0-policy

!

You can then policy route on the inbound ethernet interfaces and the traffic will be queued and policed at your desired limit.