Re: PLL Errors on 2501 -> PM3

Dick St.Peters (stpeters@NetHeaven.com)
Wed, 16 Jul 1997 19:15:25 -0400

Kyle Platts writes:

> You have a timing problem. The PM3 can only take clock from the
> loop, so the Adtran must be set up to provide clock to the span.
> The telco passes timing through the network.=20
>
> Verify that the Adtran is set to Internal clocking under config -
> network (ni) - clock source

Kyle, I have two T1s with the same setup as Kelley Lingerfelt:
cisco2501+Adtran TSU on one end, PM3 on the other.

Setting the Adtran NI clocks to INTERNAL gives PLL alarms and, on the
ciscos, CRC errors, at a rate of 3-4/min. Changing the Adtran NI
clocking to NETWORK makes the alarms and CRC errors go away.

Also, I've run a NYNEX T1 Adtran to Adtran (and 2501 to 2501) with
both ends taking clock from the network, with no alarms and no errors
for as long as 16 months. I can't swear to it, but I think it was
Adtran support that first told me to run a NYNEX line this way.

--
Dick St.Peters, stpeters@NetHeaven.com 
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