ANNOUNCE: FlowScan-1.005 released

From: Dave Plonka (
Date: Thu Oct 19 2000 - 13:52:00 PDT

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    cflowd users,

        I'm pleased to announce the release of FlowScan-1.005. FlowScan
        is a tool to monitor and graph flow information from Cisco
        routers in near real-time.

        Amonst many other things, FlowScan optionally measures and
        graphs traffic for applications such as Napster. A sample of
        what FlowScan can do is at:


    Changes in FlowScan-1.005 (since FlowScan-1.003)
        * A major performance enhancement was done resulting in FlowScan
            being about twice as fast as earlier releases. For instance,
            on a 600 MHz PIII, FlowScan can process about 3400 flows-
            per-second vs. 1700 previously. This was managed by changing
            the CampusIO and SubNetIO report modules to use the Patricia
            Tries algorithm for all IP address-based lookups. The
            Net::Patricia perl module is now required.

        * The "" template Makefile was improved to introduce some
            new "io" graphs, which show outbound traffic above the axis
            and inbound traffic below. These graphs are based on
            examples by <>. Also, the option to
            produce PNG or GIF files was added to the ""

        * The `UDPServices' option was added to CampusIO. This directive
            allows one to specify which UDP traffic should be measured,
            similarly to the CampusIO `TCPServices' option.

        * A new features was added to CampusIO which causes it to write
            flows for "other" applications (i.e. unidentified apps) to
            time-stamped raw flow files in a directory called
            "saved/other" if that directory exists. This simply makes it
            easier to study which flows are not being identified by
            service or application.

        * A routine was added to CampusIO that periodically purges old
            Real media servers from the hash cache used to identify Real
            media traffic. Previously this cache would grow without

        * Tested cflowd patch with cflowd-2-1-a9.

        FlowScan is licensed under the GNU General Public License, and
        is available to you at:


    Mailing Lists
            There are two mailing lists having to do with FlowScan:

        * flowscan
            a general mailing list for FlowScan users.

        * flowscan-announce
            a low-volume, restricted post mailing list to keep FlowScan
            users informed of news regarding FlowScan.

        The lists' respective archives are available at:




        Announcements will be "cross-posted" to both lists, so there's
        no need to join both.

        These lists are hosted by the Division of Information
        Technology's Network Engineering Technology group at the
        University of Wisconsin - Madison. To subscribe to either of
        them, send email to:


        containing either:

           subscribe flowscan


           subscribe flowscan-announce

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        If you're interested in Napster specifically, note the graph
        labeled "Well Known Services Mb/s" here:


        or, directly, here:


        I have written a general document about the Napster portion of
        the measurement at:


        Some related research on Napster flows is at:


           Alexander Kunz <>
           Kevin Gannon <>
           John Payne <>

        I'd like to thank the FlowScan beta testers (since September
        1999), early users, and participants in the FlowScan mailing
        list for their efforts and feedback.

        Also, thanks to Daniel McRobb, Tobi Oetiker, and CAIDA for
        providing the main tools upon which FlowScan is built, namely
        "cflowd" and "RRDTOOL".

    Copyright and Disclaimer
            Note that this document is provided `as is'. The information
            in it is not warranted to be correct. Use it at your own

               Copyright (c) 2000 Dave Plonka <>.
               All rights reserved.

            This document may be reproduced and distributed in its
            entirety (including this authorship, copyright, and
            permission notice), provided that no charge is made for the
            document itself.

    --  ARS:N9HZF  Madison, WI
    cflowd mailing list

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