Branch Office QoS Questions

[dtran]

Hello all !!! Hope everyone is doing well !!!!

I've got a couple QoS questions and hope someone can help clarify.

I have MPLS T1 at the branch office with QoS enabled (see QoS policy below). I allocated 40% of the T1 to the strict priority queue for voice traffic and 30% to SAP traffic and 5% for voice signaling. But for some reason users at the branch office always experience slowness whenever there is a large file transfer or download traffic going on across the WAN and it affects all applications. I am under the impression that with QoS policy that I have in place voice traffic will always get 40% of the link and SAP will always get 30% of the link then why a large download across the WAN would clog up the whole T1 link.

Thanks all in advance !!! I appreciate any inputs / suggestions !!!

D.

policy-map Voice-Over-Wan
class Critical - Voice traffic
  priority percent 40
  set dscp ef
class Flash-Override - ERP (SAP) traffic
  bandwidth percent 30
class DD-Remote-to-DR
   police rate 512000 bps
     conform-action transmit
     exceed-action drop
class voice-signaling
  bandwidth percent 5
class class-default
  fair-queue

[Edison Ortiz]

Can you post the class-maps as well and any ACLs associated to the class-maps?

Can you post show policy-map interface outputs?

What traffic is being slowed? SAP? DD-Remote-DR? Default?

[dtran]

Hello Edison !! I very much appreciate your help !!!!

Please see the attached file. I've included all associated ACL, Route-map in the file. The application that gets affected the most is SAP and it's a critical app. I don't know what I am missing in my QoS config but whenever I get called on SAP slowness, it's usually the WAN traffic load that causes the slowness.

Thanks Edison !!! I am looking forward to hear back from you !!!

Danny

[Edison Ortiz]

I don't see any drops on your interface policy-map the allocation is sufficient for the application unless not all flows are being classified properly?

Even if they fall under the class class-default, I don't see many drops there either.

Today's application may demand bandwidth greater than a T1 - how many SAP sessions are made?

How big is the location?

Do you see a lot of errors or drops on the physical interface?

I noticed you are using HSRP on the LAN interface, is the other router accepting return traffic or just sitting idle?

[dtran]

Hi Edison !! I appreciate the response !!!

The "show policy-map interface" command output that I sent earlier was capture during normal traffic load, that was most likely why you didn't any drops. Attached is the capture that I just took this morning during high traffic volume, the congestion was so bad that it affected all applications (SAP, Phone). Please have a look at the attached file and let me know what you find.

Thanks Edison !!

D.

[Edison Ortiz]

I don't see any issues from the output - how about the other end of this connection?

Does it have QoS? if so, can we see the output from that router?

[dtran]

Hi Edison !!

QoS is enabled throughout the enterprise. The issue is at the remote site and the slowness is caused by high volume in rxload traffic.

Thanks Edison !!

D.

[gerald.suiza · Accepted solution]

Hi, if you see the problem as rx load on the branch office then looking at the outbound policy may not show you the problem. you will need to get the output of the policy map applied on the PE interface facing your branch office. remember QoS should be and is always 2 way traffic in an enterprise for it to be effective.

HTH

[dtran]

Thanks Gerald !!! very much appreciate your inputs !!!

D.