QOS - how to restrict the bandwidth to branch office

[ciscoroyzhang]

                   Hi there,  in our HQ,  we have 10M leased line to AT&T cloudes,   which connect us to some brand office and  all branch offices has 2M link to AT&T.   On our  HQ,  router connect AT&T via gigbit link and  we shape the outbound traffic to 10M to reflect the guaranteed bandwidth from AT&T. Now my question is:  in HQ router is there any  menthod I can apply to specify 2M to each branch office?  Cheers...

[Joseph W. Doherty]

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Posting

Yes there is a method.  Shape traffic to each branch at 2 Mbps.

[ciscoroyzhang]

Hi Joseph,   thanks for the reply.  we have applied share to the egress interface connect to AT&T to 10M, can you advice how shape the traffic separatly to the different sites within a interface?  

[Joseph W. Doherty]

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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.

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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

At the physical interface, you might be able to apply a CBWFQ policy with a class to match destination addresses for each branch.  Each class than shapes for the corresponding branch's bandwidth.

e.g.

policy-map sample

class branch1

shape average 2000000

class branch2

shape average 2000000

class branch#

shape average 2000000

If you're using tunnels, you might shape each tunnel.

[ciscoroyzhang]

Hi Joseph, thanks for the reply.

As matter of fact, we had deployed same way with  GRE tunnels in an aggregation router which connected to a half dozen sites, it was working OK.  

But, I have not thought about this way to apply normal ethernet interface, theoretically it should work if each ACL created for every sites and associated with different class-map. I will give a test and let you know.

Now just curious, let say, from a data center there are 2M lease line to the WAN, and you have 3 sites each has 1M link each to you datacenter. How are you going to shape the bandwidth? If you shape for 1m each which is total 3M, what will happen to the packet, if total outbound traffic from datacenter to branches reach 2M. which sites traffic will be dropped first?    cheers

[Joseph W. Doherty]

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

Now just curious, let say, from a data center there are 2M lease line to the WAN, and you have 3 sites each has 1M link each to you datacenter. How are you going to shape the bandwidth? If you shape for 1m each which is total 3M, what will happen to the packet, if total outbound traffic from datacenter to branches reach 2M. which sites traffic will be dropped first?    cheers 

Ideally you would also want to shape the physical interface for 3 Mbps, and prioritize traffic to the branches.  I.e. nested shapers.  Unfortunately, I don't believe all Cisco QoS implementations would support.

More of a problem would be the reverse traffic flows, i.e. the branches aggregate is more than the hub can accept.  In that case, you would want QoS on the other side of the ingress link.  Also unfortunately, most providers won't support such QoS on many cloud technologies.