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Thu Jan 15 22:29:28 CST 2009


could be "hot". Is there any chance this would cause the card to fail after
a while? It appears this site just had 4 port Digium card fail today.

> Also, I am trying to cross connect with another Asterisk system with
> > the normal LBO setting (i.e. span=1,1,0,esf,b8zs) but as of yet the
> > systems aren't seeing each other at all. Could the side with the high
> > LBO be confusing the other side somehow?
>
> Shouldn't be... you did use a T1-crossover cable to cross-connect the
> two Asterisk boxes, right?  I've got a little T1 cross-connect diagram
> at http://www.asteriskdocs.org/cables/ if you need a reference.
>

Yes, it's a T1 cross over and this problem was resolved after plugging into
a working Digium card on the other end.

Brandon B.

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<div class=3D"gmail_quote">On Fri, Feb 27, 2009 at 7:49 PM, Jared Smith <sp=
an dir=3D"ltr">&lt;<a href=3D"mailto:jsmith at digium.com" target=3D"_blank">j=
smith at digium.com</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote"=
 style=3D"border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.=
8ex; padding-left: 1ex;">

<div>On Fri, 2009-02-27 at 14:07 -0700, Brandon B. wrote:<br>
&gt; As of yet, I am unwilling to change the LBO to 0 to where it probably<=
br>
&gt; should be because the system is working and I&#39;m not sure exactly w=
hat<br>
&gt; the LBO does. I&#39;m aware some changes were made to deal with low au=
dio<br>
&gt; levels.<br>
<br>
</div>LBO stands for Line Built Out... it&#39;s essentially a measurement o=
f the<br>
distance between your demarcation point (d-marc/smart jack/NIU) and your<br=
>
Asterisk box. =A0As you can see from a sample system.conf (from DAHDI) or<b=
r>
zaptel.conf (from Zaptel), it&#39;s an integer value from the following<br>
table:<br>
<br>
0: 0 db (CSU) / 0-133 feet (DSX-1)<br>
1: 133-266 feet (DSX-1)<br>
2: 266-399 feet (DSX-1)<br>
3: 399-533 feet (DSX-1)<br>
4: 533-655 feet (DSX-1)<br>
5: -7.5db (CSU)<br>
6: -15db (CSU)<br>
7: -22.5db (CSU)<br>
<br>
As I understand it, the LBO is effectively an attenuation value, with a<br>
higher number meaning less attenuation. =A0This way, you don&#39;t get too =
hot<br>
of a signal with a short cable, or two low of a signal on long cable.<br>
<br>
Just how far is your Asterisk box from the demarcation point?</blockquote><=
div><br>This system is connected to a CSU in the same room that provides th=
e physical T1 line. I&#39;ve always set the LBO setting at 0 for this=A0 be=
cause I&#39;ve never had a long line to deal with. Since 0 works for me, I&=
#39;m going to assume it&#39;s the correct setting with the demarc point (i=
.e. the Paradyne CSU) in the same room -- right? It&#39;s slightly confusin=
g with settings 5,6,7 labelled CSU and no description as to when to use tho=
se levels. Could you provide any suggestion for when levels 5,6,7 would be =
appropriate?<br>

<br>From what you say an LBO setting of 5 would boost the signal level, whi=
ch could be &quot;hot&quot;. Is there any chance this would cause the card =
to fail after a while? It appears this site just had 4 port Digium card fai=
l today.<br>
<br>
</div><blockquote class=3D"gmail_quote" style=3D"border-left: 1px solid rgb=
(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>&gt; A=
lso, I am trying to cross connect with another Asterisk system with<br>

&gt; the normal LBO setting (i.e. span=3D1,1,0,esf,b8zs) but as of yet the<=
br>
&gt; systems aren&#39;t seeing each other at all. Could the side with the h=
igh<br>
&gt; LBO be confusing the other side somehow?<br>
<br>
</div>Shouldn&#39;t be... you did use a T1-crossover cable to cross-connect=
 the<br>
two Asterisk boxes, right? =A0I&#39;ve got a little T1 cross-connect diagra=
m<br>
at <a href=3D"http://www.asteriskdocs.org/cables/" target=3D"_blank">http:/=
/www.asteriskdocs.org/cables/</a> if you need a reference.<br>
</blockquote><div><br>Yes, it&#39;s a T1 cross over and this problem was re=
solved after plugging into a working Digium card on the other end.<br>=A0</=
div>Brandon B.<br></div><br>

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