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QoS on WAN link

Deepak Khemani
Level 1
Level 1

Hi All

We are using MPLS service from SP to connect our branch location to DC. 

On 2 branch location where we have 2Mbps link (1:1 ratio, 2Mbps IN, 2Mbps OUT), I have found that my IN BW (download at site) is getting utilized fully and because of this user face slowness and paqcket drops.

How can I apply QoS to limit data of diffrent application downloadted at my branch site. Sjould I contacts ervice provider to apply qos on PE interface or it should on CE interface

I want to rate limit the maximum BW in IN direction (download at site)

Thanks

Deepak

2 Accepted Solutions

Accepted Solutions

Joseph W. Doherty
Hall of Fame
Hall of Fame

Disclaimer

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.

Posting

If all (or almost all) traffic to the branch is from the DC, and if your DC equipment supports it, you can shape at the DC for the branch's bandwidth.  If you chose, you can then also manage congestion under the shaper.  Or, if your SP can support egress QoS, you can have them activate it and use it.  My experience with MPLS providers, their QoS support is often limited but it can still be useful.  If you have much any site-to-site traffic, using provider QoS is almost a must.

You might also consider using QoS on branch egress.

PS:

I want to rate limit the maximum BW in IN direction (download at site)

Yes, it's often possible to police ingress at the branch, but at that is downstream of the actual congestion, results can be disappointing.

View solution in original post

Wantser1981_2
Level 1
Level 1

Agree with rr cuares. It will need to be agreed with the SP. Issue with inbound QOS is that the bandwidth is already consumed by the time it gets to your router. You would need the SP to provide priority to ensure your transit bandwidth is prioritised as desired. Any QoS you perfrom inbound will only aide delivery through your deivce and into your network, not at the pinch point of your bandwidth.

ISP qos will have a cost against it. Some services cannot provide it also depending on your SP. Worth an ask though to find out what can be done.

IF the sites are pulling data from each other, you can limit outbound from head office to remote site for example so that the download seen at the remote site is sqeezed outbound at source of download before it hits the SP. If say HTTP traffic is identified leaving DC to Branch and you limit it to 500Kbps, the remote site would only be able to recieve 0.5Mbps download as this is the max rate it can leave DC. this allows 0.5Mbps for other traffic.

This might give you an idea to help in the short term.


HTH

Wantser

View solution in original post

5 Replies 5

Rejohn Cuares
Level 4
Level 4

Apply both but it boils down what was the agreed term between you and your ISP. Did the ISP mentioned end-to-end QoS?

On another note, before applying QoS you first need to identify what traffic passing through your link. You can use NBAR in this case (run it for a minimum of 3 days). Then decide what traffic needs to be prioritized and allocated less/more bandwidth.

Please rate replies and mark question as "answered" if applicable.

Please rate replies and mark question as "answered" if applicable.

Joseph W. Doherty
Hall of Fame
Hall of Fame

Disclaimer

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.

Posting

If all (or almost all) traffic to the branch is from the DC, and if your DC equipment supports it, you can shape at the DC for the branch's bandwidth.  If you chose, you can then also manage congestion under the shaper.  Or, if your SP can support egress QoS, you can have them activate it and use it.  My experience with MPLS providers, their QoS support is often limited but it can still be useful.  If you have much any site-to-site traffic, using provider QoS is almost a must.

You might also consider using QoS on branch egress.

PS:

I want to rate limit the maximum BW in IN direction (download at site)

Yes, it's often possible to police ingress at the branch, but at that is downstream of the actual congestion, results can be disappointing.

Wantser1981_2
Level 1
Level 1

Agree with rr cuares. It will need to be agreed with the SP. Issue with inbound QOS is that the bandwidth is already consumed by the time it gets to your router. You would need the SP to provide priority to ensure your transit bandwidth is prioritised as desired. Any QoS you perfrom inbound will only aide delivery through your deivce and into your network, not at the pinch point of your bandwidth.

ISP qos will have a cost against it. Some services cannot provide it also depending on your SP. Worth an ask though to find out what can be done.

IF the sites are pulling data from each other, you can limit outbound from head office to remote site for example so that the download seen at the remote site is sqeezed outbound at source of download before it hits the SP. If say HTTP traffic is identified leaving DC to Branch and you limit it to 500Kbps, the remote site would only be able to recieve 0.5Mbps download as this is the max rate it can leave DC. this allows 0.5Mbps for other traffic.

This might give you an idea to help in the short term.


HTH

Wantser

Thanks Wantser1981

I think rate limiting at DC end is something I will go with.. Because at branch router if I configure any type of QoS, my link is choked to fullest by that time.

I have a 16Mbps link at DC. Suppose my DC link is 30% utilized, will rate limit work even if my DC  link is not fully utilized.

Thanks

Deepak Khemani

Disclaimer

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.

Posting

I have a 16Mbps link at DC. Suppose my DC link is 30% utilized, will rate limit work even if my DC  link is not fully utilized.

Yes.

I think rate limiting at DC end is something I will go with.. Because at branch router if I configure any type of QoS, my link is choked to fullest by that time.

Shaping, if supported, generally works a bit better (i.e. usually less adverse) than rate limiting.  Also if you shape for far side's bandwidth, you can usually prioritize shaped traffic and you can use all the bandwidth for "less important" traffic when there isn't "more important" traffic (not true when you rate limit).

You would police (or shape) per branch.

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