MPLS Class of Service

Unanswered Question
Mar 31st, 2008

Cn someone shed some light on a question I have pertaining to MPLS COS. My question is if I assign an application such as SAP to the I/P Interactive Data class with a guarentee 30% of bandwidth. (Type 2 Service) In my Type 2 service I have two class asssignements such as IP LAN to LAN and the least IP Access. Now I assign 40% to the LAN to LAN and the remaining goes into IP access. Now if I burst out of my 30% of bandwidth availibility for SAP, what happens to the SAP if I have no room (bandwidth) in any of my other classes. Does the traffic (SAP) get bandwidth from the IP Access class which is the lowest or does it just slow down SAP?

Thanks In Advance

I have this problem too.
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n.nandrekar Wed, 04/02/2008 - 11:15


If I understand the question right, you have the interactive data class (SAP) with 30% guarantee in addition to the 2 other classes viz. IP LAN-to-LAN (40% guarantee) and IP ACCESS (remaining). If this is the case, then whenever the SAP traffic is bursting above 30%, it will use the bandwidth available in any of the other classes. if the other classes are completely using the entire bandwidth, then the SAP traffic will be limited to 30% and rest will be tail-dropped in the queue.

So when there is free bandwidth available in any of the classes it can be used by any class that requires it. There is no tracking of "from which class" the bandwidth is used. Imagine like the free bandwidth from all the classes is present as a lot and it is used by classes that need it.




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