Packet retransmits and bad check sum on ethereal capture

Discussion in 'Cisco' started by Newbie72, Mar 9, 2006.

  1. Newbie72

    Newbie72 Guest

    I work in a hospital and we are deploying a new radiology technology
    that will allow the doctors and xray techs to view xray, catscan, mri,
    and ultra sound images digitaly instead of using the old xray films
    that most of us have seen. Here is my problem. All the workstations
    that are in the radiology wing of the hospital are somewhere in the
    neighborhood of 220-270ft of ceiling tile away from the closest switch.

    When images are attempted to be viewed over the network there is a
    delay in viewing them on the workstations in the the radiology dept. I
    captured a bunch of data using ethereal and there was a significant
    amount of rebroadcast traffic as well as bad checksums in the capture.

    Light duty traffic such as web browser and light application work fine.
    I am thinking the reason is because of the long runs in the cable

    The switch is a 24 port cisco 3550 running 100MB full on all ports with
    about half of them open.

    Output of sho proc shows the switch might as well be sleeping. It is
    idle. Memory utilization on the switch is also low.

    Am I on the right path here? Any suggestions on how to fix it?

    Thank you for all your help in advance.

    Steve Johnson
    Brooks Memorial Hospital
    Newbie72, Mar 9, 2006
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  2. Newbie72

    Merv Guest

    What type of cabling is used CAT 5?

    If so try one test run of CAT 6 cabling with the same length of cabling
    to see if problem is migitated

    In a radiology department there may be lots of interference.
    Merv, Mar 9, 2006
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  3. Newbie72

    Newbie72 Guest

    It is all Cat 5/5e. I got a cable analyzer and the longest length
    tested on the analyzer to be 212M long. Our maintenance folks that run
    the cable seem to think those numbers are not accurate. thos tested it
    with a different fluke meter and it tested 340ft at the longest run.
    Newbie72, Mar 9, 2006
  4. Newbie72

    Merv Guest

    The spec for Cat5/Cat5E is 100 metres

    Get another switch (10/100/1000) and place it as close as possible to
    the radiology dept and then run CAT 6 to the workstations
    Merv, Mar 9, 2006
  5. Newbie72

    Newbie72 Guest

    After comparing the tests of the 2 analyzers I have determined the
    first analyzer we used tested distance to and from the closet and the
    longest run is actually around 340ft or 104.61..... meters. Some of the
    drops are actually within distance but still getting low link level
    readings on the analyzers with tcp retransmits and bad check sum
    packets galore on a packet sniff. I am going to test by isolating the
    runs and plugging the machines they use in radiology directly into the
    switch today.

    Newbie72, Mar 10, 2006
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