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Cisco ATA 191 not registering


Hi All,


Good Day. 


I need some advice on the following issue. 



Cisco ATA is unable to register to CUCM and when checked on the switchport of the ATA, cdp information is also not available. 

HTTPS access to the ATA had also failed. We had to reboot the ATA to restore registration and access. This is happening frequently and i was unable to locate any bug that could cause this issue. 

Please do let me know on what could the problem be and please be noted that this is happening to multiple ATA's. 



ATA: 191 (ATA191.12-0-1SR2-3)

Services: SIP





12 Replies 12

Please connect any analog phone and try to get ip of ATA via IVR AND MAKE SURE MAC IS WHITELISTED AND PORT SHOULD BE IN VOICE VLAN.

As per my understanding you can follow bleo steps to troubleshoot the issue.

1 - first you can try to reset the ATA and assign IP gain and check the CDP.

2- Also you can check the switch port configurations / data and voice vlans
are correct.(if using data vlan also)

3- when you plug the ATA to the switch is that swithc port become connected
if yes and cdp cannot discover please reset the switch port
configuration, shut down port and add the same config and unshut the port.

if no please try by changing the patch code.

4- also you can change the switch port and try if it is possible.

As i know before the ATA get registered with the CUCM it should learn to
the connected switch. also please check whether mac address can learn from
the particular switch port.



I have rebooted the ATA and it re-registers. 

The problem is after a few days it starts happening again. 

I can see this happening to a fleet of device. 






We own 14 of the Cisco ATA 191 and find they all have the problem with dropping off.  It requires unplugging and waiting sometimes up to 20 or more minutes for it to register again.  They may work for a few days, weeks or even months, but then will eventually stop working again.  We have updated the firmware on the ATA and are on the latest call manager (currently 


The unreliability of these is horrible.


I have 6 ATA 191, they all deregister,we used them for 1 month, and they deregistered 60 times................this thing confuses me and the customer a lot....

I have the same problem with ATAs dropping off and taking forever to register once rebooted after dropping off.  And now latest batch of ATA 191 wont register period.  Cisco needs to get their act together when it comes to analog and these crap devices and actually support them.  if i am told to load more firmware and reboot my cluster again I will scream.



The issue is still appearing and i cannot seem to fix this. 

Anyone is able to advise if you have managed to address this issue. 

We have the same issue and have opened a TAC case already. It took a while to prepare a central server to be able to receive PRT reports. Finally we got such a dump and the advice from the TAC engineer was to disable the second line if not used!


This can be changed in the product specific options in the ATA device in CUCM. I'm not sure, if this will fix the issue finally, but I could see many failed requests to fetch the config file for the second line via tftp (every few minutes). It may be a good idea to disable the second line to reduce the overhead and the amount of logging on the box. Not sure why the default setting is enabled, if this is causing all the trouble.

Thank you Jan,

      Same problem like everyone else. Update firmware to the latest version does not help. Have to reboot the ATAs all the time. Follow your instruction, disabled line #2. No problem since then. It was like a month ago and still good now. No more unregistering!


Luc Giguere

We also have the same issue and we have 58 ATA. after upgrade to CUCM 12.5 no ATA191 were registered.. he only way to have them registered was to unplug hte power cord , wait and plig it back.

Pain in the ass for 58 scholls of our schoolboard.


Luc Giguere

Just upgrade from CUCM 11.0.1 to CUCM 12.5 and the ols ATA187 are Up and Running but all the brand new 58 ATA191 did not registered after the update but where working nice before the update.


Cisco must adress this issue !!!!



Agree - needs to be addressed. We have about 370 ATA191's and forever a pain of these dropping off.


Only pattern I have seen is when our gateways primary interface flips to it's back up dialer interface (SRST), they never seem to return happily when the primary interface restores. 


Would love to be able to disable second line to see if works however in a lot of case we are actually using the second line - so no point.


I just get the feeling Cisco don't really care to be honest. Long time since and fixes via firmware. Disappointing to say the least.

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