...

'tis also very important to know the route taken for a net when analyzing the data. Discrepancies here can be huge and completely invalidate any conclusions you might make about how much traffic is traversing a given path.

For this we like combined interface stats; AS-based traffic matrices are (from our point of view) mostly useful for end-to-end measurements.

Forgot to answer this one point... Combined interface stats aren't very useful for a scenario we commonly entertain: what will happen if I move Big Customer A's ingress to ANSnet from ANS border router X to ANS border router Y? I need to know who they're talking to in order to answer that question. Typically large portions of the ANS mesh will be affected, and I need to know how. Daniel ~~~~~~