WIC-1DSU-56K4 lockup

Discussion in 'Cisco' started by James, Jun 15, 2004.

  1. James

    James Guest


    I have 20+ sites with cisco 1721's and internal dsu/csu, WIC-1DSU-56K4.

    3 of these sites are experiencing intermittant lockup, mostly when
    lighting storms are in the area.

    When we arrive the TD and CD lights are lit green. Sometimes the RD
    is lit green and sometimes it is not let at all. I jack into the
    router, via console, and everything is fine with the router.
    The serial1 interface, where is where the WIC-1DSU-56K4 is installed,
    says serial line up line protocol down. The carrier (Verizon) says
    their equipment is fine. We cycle power and the router is fine. The
    circuit and our telemetry equipment start wroking fine after a reboot.
    None of the other ethernet or communications equipment is affected, or
    has power been lost nor are there ANY power feed problems. The cisco
    internal dsu/csu is locked up. Plain and simple. The carrier can loop
    up their smart jack.

    Now, can I install/configure a watchdog timer (embedded RTOS term) or
    similar software device to log and discern the downtime and when it
    reaches 15 minute, reboot the router after 15 minutes?

    YES I know I should not have to do this, but, until we figure out the
    source of the problem(s) we need a reboot bandaid. Rolling a truck in
    the middle of the night, just to cycle power, is getting expensive.

    Otherwise I've got to set up external equipment to trigger a relay,
    out of band, and thus reboot these hung routers........

    The config is dirt simple, to the point of minimalistic. It only
    occurs at 3 of 17 locations and configs are identical. IOS is version
    12.2 or 12.3, does not seem to make a difference. One would not expect
    IOS version to make a differce, as 11.1 would work with what we are

    It's a closed isolated network, so security is not at issue either.

    The bad news for us is that surveying the net reveals lots of these
    cards as refurbished, but very few as used.....which indicates a
    problem with these boards and a higher frequency of repair....


    James, Jun 15, 2004
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