There is a Java version of xplot available now called jPlot. It works in largely the same way. http://www.tcptrace.org/jPlot/ Regards, Tim -----Original Message----- From: Sam Stickland [mailto:sam_mailinglists@spacething.org] Sent: Thursday, July 17, 2008 11:53 AM To: Matt Cable Cc: nanog@nanog.org Subject: Re: Analysing traces for performance bottlenecks Matt Cable wrote:
Kevin Oberman <oberman <at> es.net> writes
tcptrace is old and pretty basic, but it can provide a LOT if information. Combined with xplot, the graphs often point to the exact nature of a TCP problem, but you need a really good understanding of TCP to figure anything out.
Wireshark also provides tcptrace-like graphs ("Statistics -> TCP Stream Graph -> Time Sequence Graph (tcptrace)"). They're not quite as pretty, but are just as effective at tracking down all sorts of TCP problems, provided, as Kevin said, you have a really good understanding of how TCP behaves
Thanks for all the replies so far. While the TCP graphs are useful they are very difficult to read in Wireshark - they really need to be displayed in xplot, but this requires an X11 setup? I've found NDT: http://e2epi.internet2.edu/ndt/ This uses a java applet hosted on a web100 patched linux server to record network diagnostics from connecting clients. A typical report might look like this: Web100 reports the Round trip time = 122.15 msec; the Packet size = 1260 Bytes; and No packet loss was observed. C2S throughput test: Packet queuing detected: 1.09% S2C throughput test: Packet queuing detected: 1.32% This connection is receiver limited 84.33% of the time. Increasing the the client's receive buffer (63.0 KB) will improve performance This connection is sender limited 1.70% of the time. Increasing the NDT server's send buffer (127.0 KB) will improve performance This connection is network limited 13.96% of the time. The theoretical network limit is 7869.69 Mbps The NDT server has a 127.0 KByte buffer which limits the throughput to 16.37 Mbps Your PC/Workstation has a 63.0 KByte buffer which limits the throughput to 4.09 Mbps The network based flow control limits the throughput to 8.73 Mbps Client Data reports link is 'OC-48', Client Acks report link is 'OC-12' Server Data reports link is 'OC-48', Server Acks report link is 'T3' Something that could provide a similar, automated analysis of a TCP stream capture is what I'm after, although I doubt a standard packet capture will be able to provided as many metric as web100 stack can. Sam ***************************************************************** This message has originated from R. L. Polk & Co., 26955 Northwestern Highway, Southfield, MI 48033. R. L. Polk & Co. sends various types of email communications. If this email message concerns the potential licensing of a Polk product or service, and you do not wish to receive further emails regarding Polk products, forward this email to Do_Not_Send@polk.com with the word "remove" in the subject line. The email and any files transmitted with it are confidential and intended solely for the individual or entity to whom they are addressed. If you have received this email in error, please delete this message and notify the Polk System Administrator at postmaster@polk.com. *****************************************************************