pchar: Child of pathchar

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pchar Child of pathchar

• (from notes on presentation
• by Bruce Mah)
• Alan Verlo, EVL

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pathchar

• Developed by Van Jacobsen, LBL (1997)
• Determine per-hop network path characteristics
• Bandwidth, propagation delay, queue time, drop
  rate
• Sends series of packets with random payload sizes
  over time to each hop in a path to determine
  bandwidth
• Attempts to assess real-world network conditions
• Alpha version (1997) is most current release
• Slides of algorithms used
  ftp.ee.lbl.gov/pathchar/msri-talk.tar.gz

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pchar

• Developed by Bruce Mah (Sandia, CA)
  ltbmah_at_ca.sandia.govgt
• Independent implementation
• Varies IP ttl to control how far into network the
  packets go, gives links traversed
• Vary packet sizes (bandwidth latency)
• Many repetitions (loss queuing)
• 32 packets for each packet size, about 40 sizes
• 1400 packets total for each hop

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pchar

• Minimums of each packet size for each hop may
  give characteristics of each hop w/o queuing
  delay
• Space between min and max curves may show
  characteristics between hops

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pchar

• To get
• www.ca.sandia.gov/bmah/Software/pchar
• FreeBSD, Solaris, Linux, Irix