Last out of service 17 - The device closed the TCP connection due to a registration timeout.

[ChrisV123]

can anyone elaborate on this? LastOutOfService=17

I have multiple 7925's and 8821's dropping calls. I've noticed in the debug display that they all have multiple instances of this out of service code. What causes this? Where should I be looking ?

[Tirtha Tripathy]

https://community.cisco.com/t5/ip-telephony-and-phones/last-out-of-services-information-on-cisco-phone/m-p/1923013/highlight/true#M188774

Check for firewall in between or any device stopping the packets intermittently.

Take a packet capture on CUCM/CME and back of the phone to find where the issue is.

Also, these are wireless phones, so see if you are in low signal strength while communicating with WCS.

Note: Use latest cisco phone firmware for phones

[ChrisV123]

Thanks for the response. I don’t believe this to be a firewall issue. We have Had several hundred of these phones for years and this problem first occurred after a recent update of the wireless lan controller. I don’t believe it to be a signal strength issue as I’ve had the issue with very good signal rates. The controller was recently updated to 8.5.161.0 but I haven’t found any documented issues regarding wireless phones