Unanswered Question
Oct 29th, 2009
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I have configured the router and modem as per the config given in the below link but it is not working. I am able to dial and successfully connect the modem but there is no display on the hypertrm.Is there anything I need to check. I am using cisco 2821 router and modem USRobotics(USR5686E).Tried with two modems and two router with all the combination but the result is same. All pls put in your inputs to resolve my problem.

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lgijssel Fri, 10/30/2009 - 01:30
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Have you used a rolled cable as described?

This is required to connect the RX and TX leads properly.

From your description, it looks as if you have a straight cable.

Best is to test first with a terminal or datatester to check the V24 interface.



NSG_POLARIS Fri, 10/30/2009 - 04:15
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Leo, I am using rolled cable only.I am not Suspecting the problem with the Router configuration.Expecting some modem configuration.If any one using USRobotics modem pls share the modem init string which is working.

Collin Clark Mon, 11/02/2009 - 12:42
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You should not need the initialization string. Make sure you have the correct cable (usually marked 'modem' on the DB25 end). Also make sure you dial and connect to the modem at baud rate 9600 with 8/None/1.

Phillip Remaker Mon, 11/09/2009 - 20:23
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Hello! Are you on the AUX or the Console port with the modem? What speed is the port to which the modem is attached?

A few quirks to be aware of:

- The speed of the modem interface has to match the speed of the serial interface of the router. If you send AT commands to the modem from a PC, the modem will lock to the speed of the interface of the PC - so when you move it, it may not re-adapt. The best way to configure the modem is by reverse telnet (if it is on AUX) because that assures that the speed is matched.

- The flowcontrol has to match the port. The console port does may assert "ready" signals, best to check with a breakout box - but if you can disable flowcontrol that is a good check.

Are there any lights on the modem? Does the DTR light up when you plug in the cable to the console port?


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