QOS on Gig port, rate limited to 100Mb

[Pete Bauer]

We're have a handful of remote sites using 2960X's and running auto qos.  They connect back to us over a provider / Ethernet service through a local company.

The CPE switch they have us plugging into is a Gig interface and our switch has a Gig interface, however we're paying for 100Mb service which they throttle somewhere on their network.

Should I be adjusting the qos commands for the uplink because it only has 100Mb/s throughput?   I'd assume the queues are setup thinking this port has 1000Mb/s connectivity when in reality it's only 100Mb.

I thought about hard coding the speed to 100Mb but I'm concerned about speed mismatch as I believe the provider side is hard coded.

Should I add srr-queue bandwidth limit 10 to the gig uplink?

Any input would be great.

Thanks

[paul driver]

Hello

You should traffic shape to the negotiated CIR of your ISP to avoid any egress blocking from your ISP between your sites.

example:
Shaping your wan link to 100mb,  provide LLQ for voice traffic and  for traffic which cannot be characterize which will use the class class-default queue  provide some fairness using WFQ

access-list 110 permit udp any any range 16384 32000
access-list 110 permit tcp any any eq 1720

class-map match-all voice
match access-group 110

Policy-map Voice_child
class voice
priority percent 5
class class-default
fair queue 

policy-map WAN_Parent

class class-default

shape average 10240000

service-policy Voice_child

int x/x (wan)

service-policy output WAN_Parent

[Georg Pauwen]

Hello,

typically, the interface command 'bandwidth' (100000 in your case - 100000 kilobits = 100 Megabits) would be used by auto qos to adjust the generated values...not sure if this works the same on the 2960x.

[paul driver]

Hello

just realised you are on about 2969x qos connecting to the isp and not a rtr 

To limit the a interface in a shared capacity over the 4 egress queues of a switchport you can use 

interface x/x

description gig interface

srr-queue bandwidth limit 10

(Which is 1/10th of 10000mb = 100mb)

[Joseph W. Doherty]

"I'd assume the queues are setup thinking this port has 1000Mb/s connectivity when in reality it's only 100Mb."

Generally, yes, that's correct.

"I thought about hard coding the speed to 100Mb but I'm concerned about speed mismatch as I believe the provider side is hard coded."

You might try to find out if that's indeed the case. QoS generally works best when port is running at end-to-end (bottleneck) speed. Otherwise you'll want to "shape", which doesn't exactly mimic an interface of the same bandwidth.

"Should I add srr-queue bandwidth limit 10 to the gig uplink?"

Well that's an "it depends" question. First, you've a QoS setup? If so, then yes, it would be needed to "trigger" your port QoS for 100 Mbps. Unfortunately, that command often isn't exact on many platforms, you might find a note about that in your manual. If it's not exact, it may throttle slower or faster than desired.

BTW, you mention remote sites, i.e. plural. It is possible for multiple sites to send to the same other site? I.e. is egress (from provider) congestion possible? If so, ideally you want your provider to also support QoS.