QoS on metro ethernet links

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Jun 24th, 2007
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We recently got a metro ethernet link (45Mbps) between 2 of our offices.

Currently we do not have any QoS services from the provider on this link.

I want to implement QoS over this link. Should i treat this as a normal P2P link and do the QoS or should i also need to ask the SP to do some sort of QoS in their MEN.

Does it really matter to have the SP do QoS as well

Note:- I will be using the link purely as a L3 P2P link

Thanks in advance


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swaroop.potdar Sun, 06/24/2007 - 20:28
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You would need the QOS on the MAN connect as well. Even though you are running a L3 P2P link you are traversing multiple L2 hops.

And where there may be contention by others traffic contending for the resources.

I believe in most cases your SP's 4 to 5 Classes would be good enough. Still you may want to understand his classes and also may want to negotiate the SLA terms.

Once this is taken care you can simply ask him to trust the incoming DSCP on the attachment circuit at his UPE.

You may also have to configure incoming DSCP trust on your Metro-CPE link which connects to you internal core routers.



Pavel Bykov Mon, 06/25/2007 - 04:43
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If you have bought a T3 end to end, with serial connections from both sides, you will not need SP QoS.

We have similar service - Structured E3s on one side, and partial structured E1s on others. Also we have unstructured E1s end-to-end. Provider just sends the signal through their MUX/DEMUXes. All the timing characteristics are governed by the standard and you cannot QoS them. The time when signal arrives is given by the clock.

If you have some other service, like MPLS, than you'd need QoS from SP.


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