From: chet johnson Subject: Re: Simulating network latency in a testbed Date: 1997/02/02 Message-ID: <32F53B14.59E@ix.netcom.com>#1/1 references: <32F21879.6E6F@vines.etn.com> <32F2601A.2D8E@mindspring.com> content-type: text/plain; charset=us-ascii organization: Netcom x-netcom-date: Sun Feb 02 7:09:29 PM CST 1997 mime-version: 1.0 reply-to: chejohns@ix.netcom.com newsgroups: comp.dcom.net-analysis,comp.dcom.frame-relay,comp.protocols.tcp-ip,comp.databases.oracle.misc x-mailer: Mozilla 3.01Gold (Win95; I) 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@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@mindspring.com > System Management Technologies, Inc. > --Internet Protocol Analysis Services > web: http://www.netkb.com voice: 770-226-0590