Re: Simulating network latency in a testbed

Jeff,

I agree with Lawrence. I use a link simulator in my lab, but have found it most suitable for demonstrating to the developer how the application will "feel" to the desktop. By performing a protocol analysis and evaluating the results, you can also look for specific remedies for an application's sensitivity to latency.

The tool I'm looking for is a defensible measure of network latency. Today I use ping (varying sizes). Since, most of the time, this is a low priority protocol my results are easily challenged. Ideally, I'd love to develop or find a mathmatical model that I can use and defend.

chet johnson
chejohns_at_ix.netcom.com

Lawrence L. Baldwin wrote:
>
> Jeff Paige wrote:
> >
> > I am trying to do an analysis of network latency requirements for a
> > set of Oracle-based client/server applications which will run over
> > national and international WAN circuits (mostly frame-relay). Since we
> > Jeff Paige
> > Eaton Corporation
> What you probably want is a link simulator...try searching on that.
>
> I've worked with T1 and T3 simulators that allow you to vary link speed
> and link latency (in either direction). Unfortunately, it's been a
> while and I can't remember any vendor names.
>
> Another option is doing a packet level transaction benchmark in a LAN
> environment (this is the approach we use). Basically, you capture each
> transaction using a standard LAN protocol analyzer. Then you take the
> protocol trace and isolate how much of the delay is due to LAN latency
> and speed. Finally, you can extrapolate these results using typically
> WAN link speeds, link propagation delays, and estimated congestion
> delays.
>
> --
> -----
> Lawrence Baldwin baldwinl_at_mindspring.com
> System Management Technologies, Inc.
> --Internet Protocol Analysis Services
> web: http://www.netkb.com voice: 770-226-0590
  Received on Sun Feb 02 1997 - 00:00:00 CST