where to find ,,keepalive'' current value in CUCM

[Michael2025]

Hi 

my CUCM version is  12.5.1.16900-48 and desktop phone are all c8841 ,  where to find ,,keepalive'' current value from desktop phone to CUCM ?

thanks

[Andrew Skelly]

I'm not sure if there is a specific "keep alive" value that shows in CUCM for phone to CUCM connection.  The closest would probably be "Detect Unified CM Connection Failure".  This can be a value of either "normal" or "delayed".  Documentation doesn't list a specific time (i.e. 5 seconds, 2 minutes, etc.).  You can find the documentation for the 8841 here:

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cuipph/8800-series/english/adminguide/P881_BK_C136782F_00_cisco-ip-phone-8800_series/P881_BK_C136782F_00_cisco-ip-phone-8811-8841_chapter_01011.html

Specifically it states this:

Determines the sensitivity that the phone has for detecting a connection failure to Cisco Unified Communications Manager (Unified CM), which is the first step before device failover to a backup Unified CM/SRST occurs.

• Normal—Detection of a Unified CM connection failure occurs at the standard system rate. Choose this value for faster recognition of a Unified CM connection failure.

• Delayed—Detection of a Unified CM connection failover occurs approximately four times slower than Normal. Choose this value if you prefer failover to be delayed slightly to give the connection the opportunity to reestablish

The precise time difference between Normal and Delayed connection failure detection depends on many variables that are constantly changing.

This field only applies to the wired Ethernet connection.

[Michael2025]

Hi Andrew

I leant a lot from you reply, thank you.

if somehow I have to  increase the KeepAlive interval in CUCM , 1 how I can realize it 1 and is there any bad impact after done increase?

[Andrew Skelly · Accepted solution]

You would change the value of the "Detect Unified CM Connection Failure" from Normal to Delayed.  That will give you a longer interval by a factor of 4.  There is no "bad" impact by doing this, it only delays a phone noticing that it lost connection back to CUCM.  I know customers that use "Delayed" for their work at home phones via Meraki, Aruba, MRA, etc. to account for delay issues over public internet.