[asterisk-users] Help With Physical Layer

[Duncan Turnbull]

------ Original Message ------
From: "Tony Kasule" <timotsmith at gmail.com>
To: "Asterisk Users Mailing List - Non-Commercial Discussion" 
<asterisk-users at lists.digium.com>
Sent: 30/06/2015 8:34:47 p.m.
Subject: Re: [asterisk-users] Help With Physical Layer

>Hello,
>
>Anyone to help me with this issue? It has never worked :(

Hi Tony

I'm not familiar with the card you but 120 ohm is usually twisted pair, 
and 75 ohm is coax (usually). If it is changeable its usually done with 
jumpers on the card. I have used RAD modems before and their cable will 
have a specific pinout that you need to match. I doubt your digium card 
by default matches the pins, but maybe, and perhaps maybe your alcatel 
did. There will be a tx pair and an rx pair and you need to make sure 
they connect to the rx and tx pairs on the digium preferably with the 
same polarity. If you are getting no signal I would think its that. You 
can use a multimeter to check for voltage on the pins.

Once you get that sorted another catch maybe timing. You will need to 
take E1 timing from one or other of the Telco's, with one as the primary 
source. If they for some reason aren't synced you will get errors every 
so often

Good luck


Cheers Duncan
>
>On Wed, May 20, 2015 at 11:34 AM, Tony Kasule <timotsmith at gmail.com> 
>wrote:
>>Hello users,
>>
>>I have a Digium Te235 and asterisk 13  which have worked well with 1 
>>carrier but we have failed to add a 2nd carrier. The second telco 
>>brings their E1 line over finer, terminated in a RAD modem and they 
>>give me ethernet to the E1 card. It's the first time i am having 
>>install such a solution, which ideally would be not a big problem.
>>
>>However, The  physical layer has failed to come up! I have tried the 
>>same setup in an Alcatel OmniOCX and it works well. I can confirm that 
>>the port is also well configured because when I interchange the cables 
>>(with the exiting cable from the other telco), the alarm clears 
>>emmediately for the 1st telco and becomes RED for the 2nd telco. A 
>>loop also clears the alarm on both ports.
>>
>>The telco has told me to make sure that Line Impedance is 120 ohms but 
>>There's no where to set that and when I was reading, I was told that 
>>E1 is already 120 ohms so no need to change anything.
>>
>>Has anyone here experienced this?  What other things can I try?
>>
>>Thank you!
>>
>>Regards,
>>Tim
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20150630/7612fbae/attachment.html>