phones get unregister and stays at registering status.

[jaheshkhan]

One of my client have strange issue. I have limited access to their infrastructure so couldnt investigate much on this.

The have BE6000s server 2921 based ... only cucm cuc and imp server is  there.

they have the issue of their phone that are already got registered and goes to registering status. Only 8841 phones having this issue. their 7945 phones not having any issue. 

when i checked i found taht none of the phone shows active and standby server..

In this case what they normally does restart the whole esxi server.. actually no need to do. but still. then all 8841 phones gets register back. then again after one day or one week or 2 weeks this issue repeats.

8841 phones i can see upgrade failed status message.

i tried to access the server directly with laptop. all esxi , cucm, all are accessible.

is this routing issue? voice vlan issue? port where server connected issue without proper mode like access or vlan?

if this is routing issue then why all phones get connected while cucm or esxi got restarted? or esxi side vlan set up issue? port group vlan issue?

what could be the reason? 

i have very limited access to switches, cucm etc. no credential provided to me yet.  i requested for it.

[piyush aghera]

Please collect phone console and RTMT logs when the phones unregister / restarts, possibly DHCP lease getting released ?  

[jaheshkhan]

why only for phones have this issue if it is DHCP release issue. why not other dhcp devices??? if its dhcp issue then why its working while restarting the cucm server?

[jaheshkhan]

Is this because of DHCP scope? if static IP of CUCM is in the range of DHCP scope there is chance of this issue right?

[piyush aghera]

Best way I believe is to collect phone console and RTMT logs to find out any error / misconfiguration when phones un-register themselves.

[jaheshkhan]

DHCP Scope was fine.

As per your request i dig RTMT logs. Reason code is 13.
cucm is 11.5

CUCM firmware version is lower than the 8841 phone firmware.
so upgrade status is showing failed.

from reason code i conclude its because of firmware mismatch only. but my question is why its like that.
phone firmware is latest compare to CUCM device defaults....

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/err_msgs/11_x/ccmalarms1151.html

Error Message

%UC_PHONE-4-DeviceImageDownloadFailure: %[DeviceName=String][IPAddress=String][Active=String][InActive=String][FailedLoadId=String][Method=Enum][FailureReason=Enum][Server=String][AppID=String][ClusterID=String][NodeID=String]: Device firmware download has failed

Explanation   Cisco IP phone failed to download its firmware load (image) for the reason defined in this alarm

Recommended Action    Verify that the IP address or hostname of the image download server (either the Load server or the TFTP server) is correct. If you're using a hostname, verify that the Domain Name Server (DNS) is accessible from the phone and can resolve the hostname. Verify that the TFTP service is activated and running on the Load server or TFTP server (the server you are using to serve firmware load files). Verify that the Load server or TFTP server is accessible from the phone. Also, refer to the reason code descriptions for recommended actions.

Method - Method used for downloading the device firmware

FailureReason - Reason that the firmware load has failed to download

Enum Definitions - FailureReason

13

The device has exceeded the internally-configured time allowed for a response from the Load server or TFTP server when requesting the firmware load file. It's possible that congestion is causing a delay in TFTP response. To allow the phone to attempt the download again, wait a few minutes then reset the phone. The phone will attempt to download the file again. If resetting the phone does not solve the issue, restart the Load server or TFTP server (whichever server provides the firmware load files).

I'm planning to do the task as mentioned in the below step:
https://community.cisco.com/t5/collaboration-voice-and-video/upgrade-downgrade-firmware-of-specific-ip-phone/ta-p/3137526

but my question is whether the device default will change firmware if i upload only the new firmware and not cop file. 

then will  CUCM again go for old firmware to downgrade??? im now trying for only one phone for time being until the problem again pops up. 

but why all these phones at a time trying for firmware upgrade when they are already in registered state.
will the cucm tell phones to upgrade or downgrade ? if so when and where we can find that?

[jason-mcgee]

jasheshkhan,

The phones will try and load whatever firmware is listed in CUCM for that model. Check GUI >>> Device >>> Device Settings >>> Device Defaults. If the default does not match what is on the tftp server, it will exhibit the behavior you are seeing. You can either upload the correct one to the tftp server or you can change the default here to the version you have on your tftp server. Seems odd that it would be different, but stranger things have occurred. You can also change it for the affected devices individually by going to the device configuration page of the affected phones and entering it under phone load name sip88xx.10-2-2-16. That is the firmware I have for 10.5.2 the one for 11.5 is sip88xx.11-7-1-17

[jaheshkhan · Accepted solution]

thank you for your reply. the root cause has found out. it was network issue only. we found one of the core switch were not responding. it was hanged. so IP Phones in edge switches connected to the core switches were not able to reach CUCM.

When phones connected directly to the switch where CUCM is connected it registered without any issue.

After restarting the core switch all phones got registered. there is some hardware issue seems for the switch. except power LED all other LED was off. even the port LEDs. i cannot login to that device asked the client to look into it,