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