=?iso-8859-1?q?Gerard=20Torin?= wrote: > > Hi Dom, we did test with TFY aplication, generating a burst > traffic of 3000 bytes UDP.
Where is the testing being done? Is it through a path that actually handles a 3000-byte packet without IP fragmentation? ATM might default to a high MTU, but if you're starting on Ethernet, then you can't use such a large MTU. So that means that you're doing IP fragmentation. That takes time and causes even more overhead from headers. UDP has an 8-byte header. IP has a 20 byte header. Ethernet supports an MTU of 1500 bytes. So, first figure out what your tool means by 3000-byte packet. Does it count headers? But probaby you want to test with 1472 at most, assuming you're starting on an Ethernet link. If you're starting on ATM, find out the MTU for the ATM interface. So, add to my list of things that affect throughput (not bandwidth): IP fragmentation and reassembly. Thanks, Priscilla > This aplication stressed the link, > but I don`t undestard why not reach the maximun bandwith > permited: 34Mbps. What do you think about this test? Is right? > > Dom wrote: > -----Original Message----- > >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of > Gerard Torin > >Sent: 05 July 2003 19:06 > >To: [EMAIL PROTECTED] > >Subject: ATM Bandwith [7:71937] > > > >Hi guys, > > >Anybody know how is built the ATM4S Bandwith?. For example, In > ATM`s > link of 34Mbps, Is true that 4Mbps is just only > >header?, I ask that, because actually my company has it. But > we don4t > reach the maximun bandwith of 34Mbps. Yesterday, we > >did stress test in the link and just only reach 30Mbps. > > >I thanks any comment. > > > Please supply more details. How did you test and with what size > packets? > Cell tax (the overhead of breaking your data down in 53byte > chunks) > might account for hat you are observing. > > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > Yahoo! Messenger > Nueva versión: Super Webcam, voz, caritas animadas, y > más #161;Gratis! > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=72002&t=71937 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
