[cisco-voip] QoS help

[Erick Wellnitz]

I'm not a LAN/Ethernet QoS guru by any means.  Our network group has
control over QoS and I'm trying to get to the bottom of an issue we've seen
routing calls over a sip trunk to a location using a 1gig Ethernet
connection on a DWDM ring.  No firewall is present.  The configuration
doesn't seem quite right to me for some reason.

Basically what we are doing is using an alternate PSTN gateway for toll
free traffic until we get additional capacity added to handle the calls.
Users report garbled audio and an 'underwater' quality of the audio.
Getting information from the phone on call quality (jitter, etc) may not
help because the calls complained about are to an external conference
bridge via tol lfree number.

If this config checks out, I plan to ask the network team if they can
capture some data for this particular link.


Here is the local end QoS config:


mls ip cef load-sharing full

mls netflow interface

mls qos map cos-dscp 0 8 16 24 32 46 48 56

mls qos

mls cef error action reset



interface GigabitEthernet3/43

description GIG 3/43

ip address X.X.X.X X.X.X.X

ip flow ingress

ip pim sparse-dense-mode

ip summary-address eigrp 1 X.X.X  X X.X.X.X

ip summary-address eigrp 1 X.X.X  X X.X.X.X

ip summary-address eigrp 1 X.X.X  X X.X.X.X

load-interval 30

wrr-queue bandwidth 30 40 30

wrr-queue queue-limit 40 30 15

wrr-queue threshold 2 60 80 100 100 100 100 100 100

wrr-queue threshold 3 60 80 100 100 100 100 100 100

wrr-queue random-detect min-threshold 1 40 60 80 80 80 80 80 80

wrr-queue random-detect max-threshold 1 70 80 100 100 100 100 100 100

no wrr-queue random-detect 2

no wrr-queue random-detect 3

wrr-queue cos-map 1 3 0

wrr-queue cos-map 2 1 1

wrr-queue cos-map 2 2 2

wrr-queue cos-map 2 3 4

wrr-queue cos-map 3 2 3

wrr-queue cos-map 3 3 6 7

mls qos trust dscp



Here is the remote end:

interface GigabitEthernet1/36

description GIGABIT E/NET 1/36

ip address X.X.X.X  X.X.X.X

ip flow ingress

ip pim sparse-dense-mode

load-interval 30

no wrr-queue random-detect 2

no wrr-queue random-detect 3

wrr-queue cos-map 1 3 0

wrr-queue cos-map 2 1 1

wrr-queue cos-map 2 2 2

wrr-queue cos-map 2 3 4

wrr-queue cos-map 3 2 3

wrr-queue cos-map 3 3 6 7

mls qos trust dscp
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