TE isn't just for congestion avoidance/mitigation. It's also for choosing the best path, based on the costs and characteristics of the traffic, as well as the load on the network. So delay-intolerant (voice, video) traffic gets preference on the lowest latency path, and pushes delay-tolerant flows to alternate higher-latency (possibly longer) unused paths. MPLS constraint-based routing allows this, as does ATM. PBR w/ IP routing would be extremely complicated to do this. Same rules can be applied to homogeneous traffic, where I can manage at a finer granularity than per-desination-CIDR-block. I can move traffic around my network internally as well as to peers, to get full utilization out of my network without introducing congestion. This presumes a network with multiple paths to a given destination, with approximately equal performance and cost. Pete. On Tue, 29 May 2001, Ukyo Kuonji wrote:

How is TE part of QoS? Maybe we are talking a different type of TE. To me, TE is the part that the traffic takes, not really what queue it sits in to transmit.

I could see a arguement for QoS being part of TE, but... (Assuming that you TE your netword so there is no conjestion.)

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Everything that you said is correct. However, you missed one important part of QoS, which is TE. TE is about avoiding congestion in the first place by more efficiently using all of the bandwidth you already have in the network. To that extent, it is a substitute for adding more pipe.