09-25-2006 07:12 AM - edited 03-15-2019 04:32 AM
We have an Avaya PBX Medpro board plugged into a 3750 port with the following configuration:
interface FastEthernet1/0/4
description PBX Medpro-1
switchport access vlan 10
switchport mode access
duplex full
speed 100
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
mls qos trust dscp
auto qos voip trust
Everything was working fine until the PBX call level went above 110 calls (G-711) which pushed the interface to more than 10mbps. When this happened random calls out of that medpro became garbled and after lots of troubleshooting we came to the conclusion that the default auto qos settings where the problem.
Default auto qos puts these statements on an interface:
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
...which means that queue 1 will allow for 10mbps of traffic and then shaping will kick in.
Adding the line 'priority-queue out' to the interface disables the 10mbps limitation of queue 1 and instead forces the interface to process every packet that goes into the priority queue before anything else.
My question is - is there a 'show' command that we can use to see shaping at work? On router ports with a service policy that has shaping or policing on it you can see the shaping/policing in real time with 'show policy....'
What about on the 3750 switch ports?
09-25-2006 11:39 AM
I've had issues many times with mepros/clan not tagging correctly. (phones you can trust all night and day)
Avaya recommends tagging at the port not trusting medpro/clan, so do not use mls qos trust dscp.
my interfaces for medpro/clan look somewhat like this:
interface FastEthernet
speed 100
duplex full
switchport access vlan
mls qos cos 5
mls qos cos override
spanning-tree portfast
no cdp enable
09-29-2006 08:07 AM
Thanks for responding. We work with DSCP so I tried your example on the port a medpro is connected to, but with DSCP, as in:
int f0/15
description Medpro-1
switchport access vlan 12
mls qos dscp 46
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
auto qos voip trust
This is the output of 'sh mls qos int f0/15'
#sh mls qos int f0/15
FastEthernet0/15
trust state: not trusted
trust mode: not trusted
trust enabled flag: ena
COS override: dis
default COS: 0
DSCP Mutation Map: Default DSCP Mutation Map
Trust device: none
qos mode: port-based
Note - it doesn't show that 'mls qos dscp 46' did anything. Also it won't take the command 'mls qos dscp override', so how do I tell to mark incoming packets to DSCP 46?
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