The MPLS WG Archive

["Erickson Trejo-Reyes" <eenet@electeng.leeds.ac.uk>]

Thank you both David and Curtis for your kind answers. Refering the following statement in the possible configuration:

 

> While CAC is fully supported it can essentially be ignored by setting a very high overbooking factor... 

 

> With the high overbooking, these tunnels come up anyway.  If there are preferred services, they get preferred treatment so the overbooking doesn't matter to them.  Best effort services temporarily get squeezed... therefore oversubscribing is much more preferrable to having CAC kick in and losing 100% of the traffic until things settle down.

 

By overbooking you mean that, for example, if a voice source can be treated as a VBR source with 64 KB peak bit rate and activity factor of 0.4, then the reservation should be made to a higher value than the computed effective bandwidth (and obviously higher than the average bit rate of 0.4 times 64KB)?

 

I had thought that, if an MPLS node is due to use only certain percentage of its total capacity to serve, for example, guaranteed services, it would not be too harmful to make reservations (up to the available percentage) only based on the sustained rate, with the only possible consequence of temporary squeezing the throughput of best-effort services. Comments?

 

Again, thanks in advanced,

 

 

Erickson