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Modem handshake US Robotics

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dughard

Technical User
Apr 8, 2004
74
GB
I have an issue with accessing a PBX (CS1K) via a US Rootics modem.
The modem answers ,but no tones are exchanged.The access to the modem is via a DDI extn down a EURO ISDN pipe.
If I access the modem from an internal extn it answers and handshakes every time.
I have tried replacing the modem with a new one,same result.
 
If I read your question correctly, you are dialing in from outside the PBX and you are not receiving modem answer tones?

Can you tell if the modem has answered your call from the outside?

If you stand next to the modem and call from your mobile, does the modem answer and try to handshake?

If so, can you hear the carrier tones at the modem, but not on your mobile?

Can you borrow the fax line and plug that into the modem? Does that line work?

It sounds like a configuration issue with the PBX not routing the incoming DID (DDI?) call to the actual modem port.


pansophic
 
Panasonic,the modem answers every time.

If I use a direct exchange line I get tones exchanged and can access the PBX software .

If I use a DDI extn off of the PBX,the modem answers, but no tones exchanged and hence no comms with the PBX
 
This may be completely off track but I throw it in FWIW...

Is you PBX a digital phone switch? I recall years ago when I had some dealings with a Meridian digital system that a special port (and hardware) needed to be provided if a user wanted to have a dialup modem connected. The digital system would not pass the analogue tones for the modem.

ROGER - G0AOZ.
 
Does a fax work on that line? Everything is pointing to a configuration issue with the line, not the modem. The configuration could be software or hardware as G0AOZ suggests. If a fax will work on the line, a modem should work as well.

There are some obvious VoIP implementations were that is not true (fax can be decoded at the ATA and sent as data until it hits a circuit-switched gateway).

At any rate, because this so obviously points to a line issue and not a modem issue, you may have better luck posting in the Nortel CS1000 forum.


pansophic
 
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