CISCO ATA 191

The Cisco ATA 191 is an analogue telephone adaptor that is used by many providers to convert IP SIP trunks to an analogue exchange line on the customers premises.

In general these work very well but as with modern telephony kit they sometimes require a tweak to get them working properly.

Issues

End devices not ringing
The main issue with these devices in the UK is that the device not ringing.  This can happen with telephones and PABX systems like Panasonic's.

The issue appears to be that these ATA's are defaulted to ring at 40vac and not the old fashioned 80vac.  The fix is to up the voltage using an internal setting within the device.

Changing the ringing voltage
To change this setting one has to gain access the ATA's web interface. This is done by connecting a computer on the same network as the ATA and using a web browser.

  1. Plug a telephone into the line 1 port on the back of the ATA.
  2. Dial **** from the telephone.
  3. Dial 110# from the telephone.
  4. The ATA will respond with a voice message advising of the devices IP address.  Note the numbers.
  5. Enter the IP address into a web browser on a computer connected to the same network.  In the address bar type the numbers, with full stops every 3 digits followed by Return e.g. XXX.XXX.XXX.XXX
  6. A web page appears and you must login.  The default logins are admin / admin or cisco / cisco.
  7. Once logged in, navigate to the Voice or Line 1 settings and locate the Ring Voltage option.
  8. Change the Ring Voltage Option from a balanced to a higher, unbalanced setting.
  9. If you cannot find these options, then your VoIP provider has most likely locked them, and you will need to contact the providers support team to have them make the change for you or advise of the user name and password.

 

Passwords
It appears that if the password is changed on the web interface it should be a minimum of 8 characters.

 

Startup Process Verification
After your ATA has power connected to it, it begins the startup process by cycling through these steps:-
  1. The Power LED flashes during the startup process.

  2. The Problem Report Tool (PRT) LED lights solid amber during initial bootup. The LED then flashes amber and then green while the application and kernel are booting.

    If the PRT LED lights red during bootup, then either the MIC certificate failed, or the ATA failed to obtain a network address.

  3. The LED for Phone 1 flashes while the Phone1 port boots, followed by the LED for Phone 2.

    After the Phone1 and Phone2 ports register with Cisco Unified CM successfully, the corresponding LEDs are lit with solid green. If a phone port fails to register, the LED rapidly flashes in green three times, then repeats.

  4. When the ATA has successfully booted, the Power LED lights solid green and the PRT LED turns off. The Network LED flashes as traffic is detected.

When you go off-hook on the phone, the phone LED begins to flash, and you hear the dial tone. The ATA has completed the startup process.

 

 

If any others issues are found with this ATA please advise.
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Last revised: February 07, 2026
FM