The MPLS WG Archive

[Fred Baker <fred@cisco.com>]

At 03:00 PM 9/26/00 -0400, Martin Picard wrote:
>   Service Providers tend to say that their backbone will never be
>   congested and if it ever gets there, then, bandwidth will be increased
>   and therefore no Congestion Management or Congestion Avoidance
>   mechanisms are necessary.

I know of a number of service providers, including BT etc, who are 
deploying services using QoS technologies. Whether or not the specific ones 
I am talking with are using MPLS in the same application, I can't say; I 
don't know, and I think some are and some aren't.

The above statement is indeed what most of the SPs say, but it misses a 
rather important fact. They are engineering their core to have enough 
bandwidth that they experience a low drop rate. That means that QoS 
perceived by their customers is not limited by their core. But it remains 
limited by the link between the edge network and the SP, which is supplied 
by the customer, and the delay and drop rates at the service provider end 
of that link are invisible to him. As often as not, it is specifically this 
link that will benefit from QoS technologies.