Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

NM-16A internal modem

my NM-16A in cisco3661 can not answer call,but U.S.robotics modem can .when I use reverse telnet to the modem, it shows no dial tone, i also use x3 to ignore the dial tone, it shows no carrier. Are some ways to solve this?


Re: NM-16A internal modem

You mean when you insert the same phone line into an USR modem it can answer the call...means the phone line is ok.

1)When you reverse telnet into the modem, can you dial out using ATDT?

2)After reverese telnetting into the modem, issue the following: AT&fs0=1

3)Try another modem you see the same issue? Or even inserting into another chassis slot (if possible)

4)Ensure the chassis is grounded properly.


New Member

Re: NM-16A internal modem

Thanks, Mak.

1.When using reverse telnet to modem, I can't dial out, it indicates NO DIALTONE.

2.I have issued AT&FS0=1,no success.

3.I have issued ATS6=5 to wait for dialtone,no success.

4.I have issued ATX3 to ignore the dialtone, it indicate NO CARRIER.



Re: NM-16A internal modem

One very important point when it comes to the modular routers, please ensure you are using the correct line number when reverse telnetting into the modems....I have seen confusion in the past on the same...expecially when testing we might be reverse telnetted on another modem versus the line being connected to another modem (this is just to make sure that the AT commands were added to the modem on which the test was carried out),

To map the interface number to a line number, multiply the slot number by 32, add the unit number, and add 1:

line number = ( * 32) + + 1

Ensure you are on the latest modem firware:

We could be having a bad hardware as well, does this happen on all the modem ports?

Thanks, Mak.

CreatePlease to create content