[Asterisk-Dev] Hooking E100P straight to telco exchange without modems.

Vinod Sankar vinod at netyantra.com
Mon Sep 15 12:19:12 MST 2003


I tried to connect a server with an E100P card directly to an E1 line from local 
Telco exchange, at their premises (informal testing) without any modems in between.
I have used E100P successfully from my company where an E1 line from the Telco is 
terminated on a RAD modem, and the modem out (RJ45) goes to the E100P card. However,
while hooking up the card directly to the telco exchange, the line does not come up.
The network sends a DM to the SABME from the card and the D channel is set to 'down'.
I can't ask too many questions there since this is an informal opportunity i got
to test, via a friend. I just wanted to know if anyone had any ideas before i
give up. Following are some observation/thoughts.

- I'm trying to run voice (not data) over this link, using libpri of asterisk.
- The same line when hooked to an ISDN modem in a cisco router shows (in router terminal) 
status as up.
- I may need a cross-cable, but would this cause such an error ? (I'd guess SABME wouldn't
at all be recognized by network since signalling will be on wrong pairs)
- There is a very very small chance that at the exchange side there is a modem,
but not on my side. I verbally checked this many times, but has no way of physically
verifying this. Would this cause such an error ?
- Would i require to put 2 modems back to back between E100P and the exchange even if
they are in the same building ?
- Would changing the extended superframe configuration make a difference ? (I'm not
certain that the line is framed or unframed)
- When the zaptel.init is run to 'start' the card, the link turns green reluctantly, but 
keeps getting frequent, periodic yellow alarms. When libpri comes up the link goes into
permanent yellow alarm and the log shows "Got DM from Peer, D-Channel is down".

would really be grateful to any pointers.


More information about the asterisk-dev mailing list