Showing results for 
Search instead for 
Did you mean: 

QoS issue - ping times increase when uploading from outside


I have an MPLS link where I have QoS configured on the outside interface (Verizon MPLS), we have noticed lately that when an user from other MPLS location tries to upload a file to the location in question, ping times to all that location increment drastically (from 200ms to 1600ms), and connectivity is extremely slow to none. I have checked ckt utilization but it is not being used at this time, so utilization is not causing the issue (2mbps line). We are able to download files from a file server located in this location, from another mpls location, but the issue arises as soon as you want to upload a file to this or any other file server located in this network. I have tested this locally and there is no issue so I discarded any performance issues on the lan or servers.

My testing also included a constant ping to the inside interface of our Cisco 1941 MPLS router, which also responds with the same high times as soon as we start trying to upload a file to the location.

I am wondering if my QoS configuration might be creating this issue, otherwise I just think this is something on the ISP side that I need to look into, can anybody give some advise on the the attached QoS config and let me know if there is something I am missing?


Lei Tian
Cisco Employee


Is that a full GE circuit or sub-rate circuit? When you upload the file from another site, what's the WAN bandwidth on that site? Does the other site have higher bandwidth circuit?

Lei Tian

Sent from Cisco Technical Support iPhone App


This is a full GE circuit. I have tried from different locations with 2, 4 and 10mbps full circuit locations with the same results.


The QoS configs looks fine, and the egress QoS shouldn't cause any problem on ingress traffic. I think the packets might queued on the other sites or inside the mpls.

Lei Tian

Sent from Cisco Technical Support iPhone App

I think it is on the MPLS, I will check with the provider, thanks for your advise.

Joseph W. Doherty
Hall of Fame Expert


The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.


Generaly, whenever you generate a load, and then see a major jump in latency, it's usually congestion caused queuing latency.  Some WAN cloud providers will provide for massive queue depths, to avoid dropping your packets, but if they do, you will then see massive RTT times.

Thanks Joseph, I have opened a ticket with Verizon, but you know that it is hard sometimes to get some help unless you can proof the issue is on their side or is very notorius. Thanks for your advise.



ad "I have checked ckt utilization but it is not being used at this time")

Have you checked the utilization in both directions?

According to your problem description I'd expect a line overload incoming direction.

You are speaking about 2Mbps circuit but your router interface is running on 10 Mbps, so 50/255 Rx traffic means 100% utilisation in fact! (As the provider is shaping the traffic to 2 Mbps probably).

What's the QoS configured on the provider side of your circuit?

Is it the same as yours?

Some providers configure just some general QoS on their PE routers saying "When the packet has arrived already to the PE router, there's no reason to make additional restrictions by a complicated QoS".

What is the bandwidth on the other site which is uploading the files to your site?

Which ports are you using for file transfer? Is it falling into the default queue together with Ping traffic?

Best regards,