Position Statement for
NSF Workshop on Internet Statistics Measurement and Analysis
Our primary concern is determing what how our switching and internetworking
equipment should evolve: both this generation of equipment and the succeeding
generations. In particular one of the key issues we face is the mapping of a
connectionless internetworking flow onto a connection-oriented network. Both
the network element capacities (connections per second, maximum active
connections, etc.) and the network element design (e.g. cache vs. full table
vs ?) are heavily influenced by the environment in which the product will be
used.
Although the notion of information gathering for network engineering is well
understood (and well deployed in certain other networks, e.g. the phone
network), there are a few basic questions about "what" should be measured:
- How should we "model" traffic in the face a continuing evolution of traffic
sources: HTTP traffic must have had some impact on flow size and RealAudio and
Xing would also seem to be likely candidates to make significant changes in
characteristics. Is it even reasonable to expect a small set of models, let
alone a single set of models,
- Today we seem to frequently assume we need to measure "flow length", "flow
creation rate", "numbers of active flows": what are we missing ?
- How can we deploy mechanisms that allow us to quickly determine, in a
global yet quantitative sense, whether or not the traffic flow "of the hour"
is similar to what the "consensus estimate" is,
To ensure that customers can still afford equipment, there are a couple of
questions aimed directly at providing a fully-instrumented solution while
containing costs:
- Is there anything to be gained by moving to a "statistical" sampling of
traffic as opposed to a "full sample" approach: at least one Ethernet hub
vendor believed there was in the LAN switching arena. Would anyone ever
accept a bill that was based on statistical sampling ?
- Can we distinguish between "long term statistics" that are "always"
collected for network engineering reasons and "special study statistics" that
are used to isolate the cause of performance problems.
To a certain extent, answering these questions may be a simple matter of
moving the "state of the art" into the "state of practice".