NM-8AM not negotiating dialin calls

[mosesals]

Hi guys,

We have a CISCO 2610XM router w/ NM-8AM module serving our remote mobile dialup users.

The server works fine until recently wherein the modem seems not to answer anymore the incoming calls (no handshake). Sometimes the modem answers but only with a different noise than a modem handshaking.

The lines connected in the NM-8AM modems works fine when attached to an external modem (hayes) and faxes. The strange thing is that when I connected another set of analog lines (from another building) to the NM-8AM modems, they work. Now I have a hard time convincing the telco that it's a line problem.

I've attached here some info on my config and the modem config/status/debug details for your reference.

I hope you can advise me on what to do.

Thank you very much.

[tepatel]

Its little hard to troubleshoot these type of inconsistant issues where one set of analog line works fine with nm-8am while another set of lines doesn't. Try following.

Reload the box, if possible. Then use one known good working analog line, one-by-one in each nm-8am and see if that works fine.

Now also you can reverse telnet to those modems (one-by-one) from nm-8am and try dialin or dialout to a PC with modem and hyperterminal session and see how that behaves. With reverse telnet session, you will see RING and CONNECT message.

If no luck at all, try the connection at lower speed..may be 9600 baud.

[mosesals]

you bet... i'm really getting headaches here. :)

have tried your suggestion, unfortunately without success. below are the messages. still "no carrier" even when dialing out from the router's modems.

will setting the guard tone help? what is the guard tone for?

we're now getting disperate.

tnx a lot.

--------------------

at

OK

atdt5809789

NO CARRIER

atdt5809789

NO CARRIER

atz

OK

atdt5809789

NO CARRIER

atdt5809789

NO CARRIER

---------------------

mnlac000#

19:27:43: Modem 1/0 Mcom: in modem state 'Dialing/Answering'

19:28:47: Modem 1/0 Mcom: in modem state 'Disconnecting'

19:28:47: %MODEM_HIST-3-END_CALL: MCOM Modem 1/0

Connect Protocol - Unkn, Compression - Unkn, Connected Standard - Unkn

Tx/Rx bit rate - 0/0

Call Time - 00:00:00, Disconnect Reason (0x2) - No carrier

0/0 retrains initiated/accepted, 0/0 speedshifts initiated/accepted

0 chars tx, 196 chars rx

19:28:47: Modem 1/0 Mcom: DISCONNECT, duration = 00:00:00, reason (0x2) No carri

er

19:28:48: Modem 1/0 Mcom: in modem state 'Idle'

19:29:59: TTY67: timer type 1 expired

19:29:59: TTY67: Exec timer (continued)

[makchitale]

Can you please try out the following?

1. Reverse telnet into one modem on the NM-AM & see if we can make a call out (using the same old lines)

2. Is the chassis grounded properly?

3. Remove “modem autoconfig discovery” from under the lines.

4. If possible move the NM-AM card to another chassis (the 2610xm has only one slot) & see if that works?

Results of the above will gives us further steps for troubleshooting this issue.

Thanks, Mak

[mosesals]

hi,

tnx for the advise.

1. can also get a connection using reverse telnet. same reason for disconnection, "no carrier".

2. unfortunately, the chassis is not connected to earth ground, although the power source is. we'll try to have earth grounding on the chassis.

3. removing "modem autodiscovery" did give any change in the error encounterd.

4. unfortunately, the 2600xm series is on a per order basis here, and we don't have another router of same type, and we don't have the SMARTNET service of cisco also. this means we have to wait for 30-45 days before we can get a new unit for isolation purposes. our supplier also is not very cooperative since the unit is working when tested in their area.

i hope it's only the grounding that matters here.

tnx.

[mosesals]

hi,

we have already installed earth grounding on the router chasis. unfortunately, it didn't help. we still have the same problem.

i've already asked supplier to arrange for a replace ment of the entire machine. now, i have to wait for it.

would anybody here have heard of this kind of line problem? can we insist on telco that the problem really is a line problem?

tnx.