[Asterisk-Users] Channel Bank Frustrations

[George Pajari]

I'm trying to get a Carrier Access Corp. Channel Bank I working with a
Digium T100P without success.

What is stranger is that the status lights on the channel bank and T100P
seem to change almost each time I power cycle the channel bank or reset the
T100P.

The channel bank has three status lights: T1, Framing, Status. T1 is green,
Status is yellow, and Framing is usually red but sometime green.

The T100P is sometimes red, sometimes green.

The zaptel configuration is:
    span=1,0,0,esf,b8zs

The channel bank settings are:
    Clock source: On or Off, seems not to make a difference
    Framing: ESF
    Line Code: B8ZS
    CSU: On or Off, seems not to make a difference

Once I managed to get all three status lights on the channel bank green but
the T100P was red.

On the few cases the T100P gives a green status, zttool shows the RxB bits
randomly flipping one and off.

I have tried different T100P cards in different servers so that has been
eliminated as a cause.

I have made up several T1 loopback cables so I don't think it is a flaky
cable.

The remaining possibilities are:
 a) a bad channel bank (although it passes the self test)
 b) a bad zaptel configuration

After several hours of trying different settings and DIP switches I am
increasingly frustrated in trying to determine the cause of the problem. It
has been especially difficult since power cycling the channel bank can
result in a change to the status lights without any change to the settings
or configuration.

Any suggestions on what might be causing the problem or what to try next?
We're trying to go live this week and this problem is critical.

Thanks for any help/suggestions

g.

P.S. - What, exactly, is the meaning of the second argument to the zaptel
span parameter ("timing source") and how does it relate to the clock switch
on the channel bank as I have tried all four combinations without obvious
consistent affect?