auto qos voip trust

[fotismark]

Hello and happy NY

I have a quick question.

I have a Switch, with only phones on it on internal network, which leads to another switch that connects to Call Center.

Will auto qos work with no other config ? Its a cisco 3560.

Do I need to set the COS value to 5 to every port? And what about the port that leads to main Switch?

Do I ned to do piority queue out? There are so many ways to configure QoS so a little help would be appreciate.

I know that Auto Qos won't work if

1- Ip Routing and Ip Cef must be enabled

2-Port must be switchport access

3-Bandwidth on each port must be set

Below the config of one of the ports.

interface FastEthernet0/3
 description grandstream_phones
 switchport mode access
 bandwidth 100000
 speed 100
 srr-queue bandwidth share 10 10 60 20
 srr-queue bandwidth shape  10  0  0  0
 priority-queue out
 mls qos cos 5
 mls qos trust cos
 auto qos voip trust
 spanning-tree portfast
end

#sh mls qos int fa0/2
FastEthernet0/2
trust state: trust cos
trust mode: trust cos
trust enabled flag: ena
COS override: dis
default COS: 5
DSCP Mutation Map: Default DSCP Mutation Map
Trust device: none
qos mode: port-based

Can someone explain to me the output of

Trust Device: none <--- Why none?

FastEthernet0/3

  dscp: incoming  
-------------------------------

  0 -  4 :          88            0            0            0            0  
  5 -  9 :           0            0            0            0            0  
 10 - 14 :           0            0            0            0            0  
 15 - 19 :           0            0            0            0            0  
 20 - 24 :           0            0            0            0            0  
 25 - 29 :           0           84            0            0            0  
 30 - 34 :           0            0            0            0            0  
 35 - 39 :           0            0            0            0            0  
 40 - 44 :           0            0            0            0            0  
 45 - 49 :           0            0            0            0            0  
 50 - 54 :           0            0            0            0            0  
 55 - 59 :           0            0            0            0            0  
 60 - 64 :           0            0            0            0  
  dscp: outgoing
-------------------------------

  0 -  4 :        6745            0            0            0            0  
  5 -  9 :           0            0            0            0            0  
 10 - 14 :           0            0            0            0            0  
 15 - 19 :           0            0            0            0            0  
 20 - 24 :           0            0            0            0            1  
 25 - 29 :           0            0            0            0            0  
 30 - 34 :           0            0            0            0            0  
 35 - 39 :           0            0            0            0            0  
 40 - 44 :           0            0            0            0            0  
 45 - 49 :           0            7            0            0            0  
 50 - 54 :           0            0            0            0            0  
 55 - 59 :           0          107            0            0            0  
 60 - 64 :           0            0            0            0  
  cos: incoming  
-------------------------------

  0 -  4 :         229            0            0            0            0  
  5 -  7 :          32            0            0  
  cos: outgoing
-------------------------------

  0 -  4 :       25436            0            0            0            0  
  5 -  7 :           8            0            0  
Policer: Inprofile:            0 OutofProfile:            0

On the stats the CoS incoming and outgoing 5-7 have some values....but so from 0-4.

I don't understand why 0-4 have increment values since there is only Voip Phones on them.

[Mark Malone]

If only phones are on the network there is probably no need then for qos as the switch ports are not going to be under any pressure , better off using DSCP if available than cos , mls qos trust dscp , as that covers the l3 as a phones marks at l2 and l3 , cos being the l2 , if DSCP all the way through no need to re-map from cos ., if cos only supported use mls qos trust cos at the access port and uplink if you really want to enable it and you can turn it on globally as well with mls qos , if there cisco phones attached you can also use mls qos trust device cisco-phone , the reason to use DSCP is it wont be stripped by upstream trunk so if available just set trust dscp on access and uplink

[paul driver]

Hello

Also just like to add that you are also shape prioritising the queue 1 of each port to10mb with this config which will overide the other 3 queues and possible stave them if there isnt enough BW to be shared between them.

interface 

speed 100
srr-queue bandwidth shape  10  0  0  0
priority-queue out

res

Paul