[asterisk-users] ISDN PRI configuration

[Kevin P. Fleming]

On 12/07/2011 04:15 PM, Steve Edwards wrote:
> On Wed, 7 Dec 2011, Vieri wrote:
>
>> A telco has recently installed a new line in our building and I need
>> to connect it to my Asterisk server with a Digium PRI card.
>>
>> It's not the first time I set up and configure a PRI link but I'm
>> failing to make this one work.
>>
>> chan_dahdi.c: No D-channels available! Using Primary channel 16 as
>> D-channel anyway!
>
> We usually get D channels on the first channel of the first T1 in an
> NFAS group and the last channel of the last t1.
>
> However, telcos don't always get the order right. I've spent hours
> trying configurations and varying the D channel. Sometimes it's just
> that they number things in a different order than we were expecting.
> Sometimes, it almost appears that they use a dartboard :)

Vieri: You aren't even far enough along to worry about D-channel 
assignments or anything like that. Your span is in RED alarm; that means 
it can't see the far end at all. Until you get that cured (layer 1 - 
physical layer) nothing above it is going to work.

Since they mentioned HDB3 and CRC4, you most definitely have an E1 span, 
and you will need to specify 'CCS' as well because you are using ISDN 
signaling. If the line coding/framing settings are wrong that *could* 
result in a RED alarm, but doesn't always.

So, you need to start by getting the span to come out of RED alarm (to 
go 'green'). This could be a cabling problem, a hardware problem, or it 
could something as simple as the fact that the telco hasn't actually 
'turned up' the span yet, because they don't usually do that until you 
have your equipment plugged in and you call them to tell them that you 
are ready for the span to be turned up.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
Jabber: kfleming at digium.com | SIP: kpfleming at digium.com | Skype: kpfleming
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at www.digium.com & www.asterisk.org