PRI Problem

Home » Asterisk Users » PRI Problem
Asterisk Users No Comments

On Tue, Aug 16, 2011 at 10:48 AM, Shaun Ruffell wrote:
> On Tue, Aug 16, 2011 at 10:31:54AM -0400, Eric Merkel wrote:
>> I am having a problem with a new PRI turn-up on dahdi 2.5.0 and
>> asterisk 1.8.5 that I have not seen before. The PRI is setup as B8ZS,
>> ESF and the span shows up and ok. This PRI is merely a crossover T1
>> going into an old DC0 class 5 switch.
>
> I’m not familiar with this switch however…
>
>> I am getting the following errors over and over again
>>
>> [Aug 16 10:26:10] NOTICE[8002]: chan_dahdi.c:3043
>> my_handle_dchan_exception: PRI got event: HDLC Bad FCS (8) on
>> D-channel of span 1
>> [Aug 16 10:26:10] NOTICE[8002]: chan_dahdi.c:3043
>> my_handle_dchan_exception: PRI got event: HDLC Abort (6) on D-channel
>> of span 1
>
> Do these errors start right away or does it take a little bit of time
> before they start appearing?
>

The error pretty much right away.

>> I am also showing CRC4 errors on span as well.
>>
>> # asterisk -rx “dahdi show status”
>> Description                              Alarms  IRQ    bpviol CRC4
>> Fra Codi Options  LBO
>> T2XXP (PCI) Card 0 Span 1                OK      1      0      2938622
>> ESF B8ZS          0 db (CSU)/0-133 feet (DSX-1)
>>
>> I am leaning towards a misconfiguration on the span on the switch side
>> but here is my setup. Can anyone point me in the right direction?
>>
>> # dahdi_hardware
>> pci:0000:06:08.0     wct4xxp+     d161:1220 Wildcard TE220 (5th Gen)
>>
>> /etc/dahdi/system.conf
>> # Span 1: TE2/0/1 “T2XXP (PCI) Card 0 Span 1” (MASTER) B8ZS/ESF ClockSource
>> span=1,1,0,esf,b8zs
>> # termtype: unknown
>> bchan=1-23
>> dchan=24
>> echocanceller=mg2,1-23
>
> You have this configured for the switch to provide you timing. Is the
> switch really expecting to provide timing to the TE220?
>

I guess I was just assuming the switch would provide the timing as the
telco normally provides this. Would you recommend just turning the
timing off?

>> /etc/asterisk/chan_dahdi
>> [channels]
>> language=en
>> context=Incoming-Pri
>> switchtype=dms100
>> signalling=pri_cpe
>> group=1
>> channel => 1-23
>>
>> Thanks,
>> Eric Merkel
>
> —
> Shaun Ruffell
> Digium, Inc. | Linux Kernel Developer
> 445 Jan Davis Drive NW – Huntsville, AL 35806 – USA
> Check us out at: www.digium.com & www.asterisk.org
>
> —

Thanks,
Eric