10mbps on 100mps Bearer BT IP Clear - Shape?

[Jason Nash]

Hi All,

We have a BT IP Clear circuit (wires only MPLS) which has been ordered with 10mbps of bandwidth, it has been provided as a 100mbps ethernet circuit. Would you normally need to apply shaping to the outbound interface in order to prevent the traffic exceeding 10mbps in this situation? I assume although the circuit is provided as 100mbps the provider will have some policing in place to limit this to the 10mps. Can I rely on their network to control this or will they just drop traffic exceeding the 10mbps of ordered bandwidth.

If shaping is required what is the best command to use, I am currently using shape average but I am not sure if this is needed or the best way of doing this.

We are currently seeing pings on this circuit of around 10ms, is this to be expected for this type of circuit? We have other site to site 10mbps Ethernet links between our own sites and on these we see pings of around 1ms.

Does anyone have any experience of these circuits, can you advise?

Jason

[smitesh kharecha]

Hi Jason,

Too many question...

Yes, if you exceed 10 Mbps, exceeding traffic CAN / WILL be dropped by provider.

Regarding ping response time, you need to check your SLA document and also from where to where you are seeing that latency.

Regards,

Smitesh

[Joseph W. Doherty]

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Posting

If the provider polices their bandwidth rate, then shaping is a really good idea.  Even if they shape their rate, you may still want to shape yourself as to have control over how packets are prioritized.

BTW, when you shape, if your shaper doesn't account for L2 overhead, you may want to shape the L3 rate down by the expected L2 overhead.

As to you ping times between sites, is there any major difference in physical distances between sites?

What's the logical topology between sites, p2p or multipoint?  If the latter, is egress congestion possible?

[Jason Nash]

Thanks Joseph.

This is really useful. What is the best way to shape, is a policy map using shape average using a service policy output on the interface the best way to do this? I currently have the bandwidth command on the interface set to bandwidth 10000.

Not too concerned about the ping, I just wanted to ensure what we were seeing with this was to be expected as we had not used the BT MPLS network before. Previous we have just worked with point to point lan extensions between sites.

We have a 10mbps on (100mbps bearer) Ethernet extension link into BTs MPLS network; we then have remote sites connected into the MPLS cloud via ADSL links.

Jason

Jason Nash

Network Engineer

Somer Housing Group

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[Joseph W. Doherty · Accepted solution]

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

Yes, that's what I would normally use, i.e. a policy map with a shaper.  (Allows you to add other QoS features, if needed).  (NB: BTW, Cisco shapers normally dequeue using WFQ or FQ.)

If your WAN topology now is multipoint, you might have congestion coming out of the cloud.  Usual solution for this is the MPLS provider supports some kind of QoS model.

For your ADSL links you probably should shape them too for their upstream bandwidths.