Cisco MC3810 T1 clocking problem

Discussion in 'Cisco' started by Ed M, Oct 31, 2003.

  1. Ed M

    Ed M Guest

    We have several MC3810's in use in our system. Both voice and fax work well
    on all of them except for one that is attached to a Mitel SX2000 PBX (the
    others are all on Mitel SX200's.) On that one faxes often fail during
    transmission and if they succeed they always shift down to only 2400 baud.
    I suspect that we have a clocking problem but I don't know how to solve it.
    The T1 controller has automatically switched to "loop-timed" even though
    I've configured it to "clock source line" There is no mention in Cisco
    documenation about why a T1 Controller would decide to automatically switch
    to Loop-timed.
    Does anyone know?

    Here's a SHOW CONTROLLER T1 1:

    T1 1 is up.
    Applique type is Channelized T1
    Cablelength is long gain36 0db
    No alarms detected.
    alarm-trigger is not set
    Slot 4 CSU Serial #09480883 Model TEB HWVersion 6.00 RX level = 0DB
    Configured clock mode swapped to Loop-timed by priority clocking!!
    Framing is SF, Line Code is AMI, Clock Source is Line.
    Ed M, Oct 31, 2003
    #1
    1. Advertising

  2. Ed M

    Fred Newton Guest

    If the Line coding is AMI should the framing not be D4?


    "Ed M" <> wrote in message
    news:nFtob.7750$...
    > We have several MC3810's in use in our system. Both voice and fax work

    well
    > on all of them except for one that is attached to a Mitel SX2000 PBX (the
    > others are all on Mitel SX200's.) On that one faxes often fail during
    > transmission and if they succeed they always shift down to only 2400 baud.
    > I suspect that we have a clocking problem but I don't know how to solve

    it.
    > The T1 controller has automatically switched to "loop-timed" even though
    > I've configured it to "clock source line" There is no mention in Cisco
    > documenation about why a T1 Controller would decide to automatically

    switch
    > to Loop-timed.
    > Does anyone know?
    >
    > Here's a SHOW CONTROLLER T1 1:
    >
    > T1 1 is up.
    > Applique type is Channelized T1
    > Cablelength is long gain36 0db
    > No alarms detected.
    > alarm-trigger is not set
    > Slot 4 CSU Serial #09480883 Model TEB HWVersion 6.00 RX level = 0DB
    > Configured clock mode swapped to Loop-timed by priority clocking!!
    > Framing is SF, Line Code is AMI, Clock Source is Line.
    >
    >
    Fred Newton, Nov 1, 2003
    #2
    1. Advertising

  3. Ed M

    Fred Newton Guest

    Further to that the timeslots would be 56K and not 64K as with B8ZS ESF.

    "Fred Newton" <> wrote in message
    news:EJWob.251536$pl3.61973@pd7tw3no...
    > If the Line coding is AMI should the framing not be D4?
    >
    >
    > "Ed M" <> wrote in message
    > news:nFtob.7750$...
    > > We have several MC3810's in use in our system. Both voice and fax work

    > well
    > > on all of them except for one that is attached to a Mitel SX2000 PBX

    (the
    > > others are all on Mitel SX200's.) On that one faxes often fail during
    > > transmission and if they succeed they always shift down to only 2400

    baud.
    > > I suspect that we have a clocking problem but I don't know how to solve

    > it.
    > > The T1 controller has automatically switched to "loop-timed" even though
    > > I've configured it to "clock source line" There is no mention in Cisco
    > > documenation about why a T1 Controller would decide to automatically

    > switch
    > > to Loop-timed.
    > > Does anyone know?
    > >
    > > Here's a SHOW CONTROLLER T1 1:
    > >
    > > T1 1 is up.
    > > Applique type is Channelized T1
    > > Cablelength is long gain36 0db
    > > No alarms detected.
    > > alarm-trigger is not set
    > > Slot 4 CSU Serial #09480883 Model TEB HWVersion 6.00 RX level = 0DB
    > > Configured clock mode swapped to Loop-timed by priority clocking!!
    > > Framing is SF, Line Code is AMI, Clock Source is Line.
    > >
    > >

    >
    >
    Fred Newton, Nov 2, 2003
    #3
  4. Ed M

    Ed M Guest

    I tried setting the framing to both B8ZS and D4 but it made no difference.
    I've just solved the problem by trying several IOS images and finally found
    a very old one that works. Apparently something broke in more recent ones.
    Strange

    "Fred Newton" <> wrote in message
    news:KqZob.253234$6C4.232876@pd7tw1no...
    > Further to that the timeslots would be 56K and not 64K as with B8ZS ESF.
    >
    > "Fred Newton" <> wrote in message
    > news:EJWob.251536$pl3.61973@pd7tw3no...
    > > If the Line coding is AMI should the framing not be D4?
    > >
    > >
    > > "Ed M" <> wrote in message
    > > news:nFtob.7750$...
    > > > We have several MC3810's in use in our system. Both voice and fax

    work
    > > well
    > > > on all of them except for one that is attached to a Mitel SX2000 PBX

    > (the
    > > > others are all on Mitel SX200's.) On that one faxes often fail during
    > > > transmission and if they succeed they always shift down to only 2400

    > baud.
    > > > I suspect that we have a clocking problem but I don't know how to

    solve
    > > it.
    > > > The T1 controller has automatically switched to "loop-timed" even

    though
    > > > I've configured it to "clock source line" There is no mention in

    Cisco
    > > > documenation about why a T1 Controller would decide to automatically

    > > switch
    > > > to Loop-timed.
    > > > Does anyone know?
    > > >
    > > > Here's a SHOW CONTROLLER T1 1:
    > > >
    > > > T1 1 is up.
    > > > Applique type is Channelized T1
    > > > Cablelength is long gain36 0db
    > > > No alarms detected.
    > > > alarm-trigger is not set
    > > > Slot 4 CSU Serial #09480883 Model TEB HWVersion 6.00 RX level = 0DB
    > > > Configured clock mode swapped to Loop-timed by priority clocking!!
    > > > Framing is SF, Line Code is AMI, Clock Source is Line.
    > > >
    > > >

    > >
    > >

    >
    >
    Ed M, Nov 4, 2003
    #4
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. JFerri
    Replies:
    1
    Views:
    530
    FireSword
    Nov 19, 2003
  2. Henry Yen

    Re: VWIC-2MFT-T1 card and clocking

    Henry Yen, Apr 15, 2004, in forum: Cisco
    Replies:
    0
    Views:
    3,000
    Henry Yen
    Apr 15, 2004
  3. Replies:
    2
    Views:
    4,859
  4. joevan

    clocking computer

    joevan, Aug 5, 2004, in forum: Computer Support
    Replies:
    8
    Views:
    857
    joevan
    Aug 7, 2004
  5. dgv69

    problem with cisco mc3810

    dgv69, Oct 21, 2008, in forum: Hardware
    Replies:
    0
    Views:
    1,029
    dgv69
    Oct 21, 2008
Loading...

Share This Page