traffic classification mechanisms

[Robert Pezick <rpezick () squirehome org>]

This query is part of a marketing survey on the utility of today's QoS
features.   All input would be appreciated.

The question addresses the real-world utility of the basic edge traffic
aggregation/QoS mechanisms that vendors  provide these days, in
particular if and how often operators actually use them.   A common
function in today's edge equipment is the classification of packets
based on layer 2, layer 3, and layer 4 packet header fields.  In
particular, classification based on
 - layer 2: MAC addresses, ethertype, etc
 - layer 3: source IP, dest IP, ToS, protocol
 - layer 4: TCP/UDP source/destination port
The edge equipment will generally classify traffic into flows based on
these characteristics and then perform some policing and/or marking
functions on that stream.

1) Do you use these facilities?  rarely, somewhat, often?
2) Are there particular classification methods out of the standard list
that you use more often then others?

Any help is appreciated.  Thanks.

- Rob