Shaper in network

[cisco8887]

Hi Guys,

is there a way to find out what device is shaping traffic ?

I think answer is no and you have to login to all devices to check

issue I have is upload speed is at full wire speed but download speed is limited .

I have narrowed it down and it is not the ASA and core switch .

I think it is the access switch .

I am no expert at QoS so seeing the following config on the port connected to my test pc

could below be causing it ?

What below reads to me is the legacy priority queue so anything that is part of the priority queue will be served first which can potentially starve bandwidth for other traffic

SRR share means it has 4 queues I think with 10 percent assigned to each queue, right ?

do you need to check the policy-map to work out what traffic falls into what queue?

 mls qos trust cos
 mls qos trust device cisco-phone
 priority-queue out
 queue-set 2
 srr-queue bandwidth share 10 10 60 20

many thanks

[Mark Malone]

Hi

real shaping is usually done at the wan interface where the actual MQC service policy is applied have you checked there to see if there's restrictions ?

that what you have posted is shaping but its at layer 2 hardware shaping , srr is shaped round robin queuing while other platforms can have wrr weighted round robin --- this should show you if the interface is having an issue and dropping packets , as well check is the interface clean of errors and output drops too  --sh mls qos interface gx/x statistics

that should only be effecting your access port and how it queues traffic per that port MLS can cause issues but if your using MLS you most likely have MQC applied t layer 3 somewhere at the wan and that's where the real restrictions maybe policing and shaping , that port is giving voice priority to empty that queue before servicing the other queues ,  you could remove MLS globally as a test  but I would look for the class-maps policy-maps at layer 3 first see if there is something configured , we restrict all downloading on certain apps with policing/shaping to prevent people hammering our links you could be doing the same somewhere on the routers or layer 3 switch

[cisco8887]

many thanks for this.

Is SRR a hardward shaper rather than software?

I have checked and there is no shaper/policier along the way on the WAN interface so puzzled as to what is causing the issue.

If I understand correctly,  the commands above do the following:

change the default queue set to 2 which will have 4 queues egress and 2 ingress.

it is configuring egress traffic to have 4 queues of 10, 10 , 60 and 40 percent of the bandwidth and it is in shared mode meaning they can go above the their allocated bandwidth percentage

priority queue out is setting queue out to be priority  ? which one of the 4 above queues will it be ?

[Mark Malone]

there software queues but based on what's the hardware is capable of , MQC is layer 3 software based

If I understand correctly,  the commands above do the following:

change the default queue set to 2 which will have 4 queues egress and 2 ingress.

it is configuring egress traffic to have 4 queues of 10, 10 , 60 and 40 percent of the bandwidth and it is in shared mode meaning they can go above the their allocated bandwidth percentage

Have you seen this link its all very well explained and how the queues work worth a read .......

https://supportforums.cisco.com/document/31581/egress-qos

priority queue out is setting queue out to be priority  ? which one of the 4 above queues will it be ? its always queue 1 unless changed , from memory only queue1 or 2 cane be priority