[asterisk-users] ISDN PRI configuration

Kevin P. Fleming kpfleming at digium.com
Wed Dec 7 16:54:40 CST 2011


On 12/07/2011 04:51 PM, Vieri wrote:
>
>
> --- On Wed, 12/7/11, Kevin P. Fleming<kpfleming at digium.com>  wrote:
>
>> 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.
>
> They "should" have turned it up, or at least that's what one of the tech guys told me.
> But I guess I'll have to check with them again.
>
> The cable should be ok (standard ethernet cable) but I didn't actually install it myself (I'm in a remote location) so I'll have to check that too.

Standard Ethernet cables do not always work for T-1/E-1 spans. They do 
work a rather large percentage of the time, but not always. Distance 
between the NIU and the T-1/E-1 card can be a factor, among other things.

Many Digium products include span loopback devices, that you can plug a 
cable into and generate a hard loopback towards the card. If there is 
one of those on-site, have someone unplug the cable from the NIU and 
plug it into the loopback device instead; if the span goes green, then 
at least your cabling/wiring are OK.

-- 
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



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