Hi,
Given a switch having dubious documentation ("This is the power plug. These are the network connection points. *Fini*"), what sorts of techniques might be fruitful in empirically deriving the characteristics of the switch? I'm looking for solutions that can be deployed "unattended" and for low cost (i.e., part of a deployed system instead of a special stand-alone device)
[Note that, for the time being, I am only interested in temporal characterizations. I am, also, willing to assume that all ports behave identically]E.g., as a minimum, you would want to know any *fixed* latencies involved in frame routing.
Beyond that, the policy(ies) that the switch uses for routing frames (cut-through, store-and-forward, adaptive, hybrid, etc.) and the structure and depth of its elastic store.
The goal of this exercise is to be able to quantify the range of transport delays an arbitrary frame is likely to experience when it encounters the switch.
AFAICT, there is no way to do this without also being able to characterize the NIC(s) in your "tester" (i.e., if you can't predict how rames get placed onto -- and pulled off of -- the wire on *your* end, then this is a big variable in the overall process).
Thanks!
--don