ISR 3945E not showing "Debug isdn q931" output

[yusuf.ujjainwala]

ISR 3945E not showing out put for "debug isdn q931" command.

but it showing logs for debug command like "ccsip" and "voice ccapi inout" etc.

version 15.5
service timestamps debug datetime msec
service timestamps log datetime msec
!
!
logging queue-limit 10000
logging buffered 51200 warnings
logging rate-limit 10000

IOS: Version 15.1(1r)T5, RELEASE SOFTWARE (fc1) / c3900e-universalk9-mz.SPA.155-3.M4a.bin

[Jonathan Schulenberg]

Most likely because those debugs weren’t disabled after being used at some point in the past. Do they show up in the output of “show debug” as enabled? Does an “undebug all” and then enabling only your Q931 debug resolve the issue?

[DaviRocK!]

You can check here

https://community.cisco.com/t5/networking-documents/how-to-configure-logging-in-cisco-ios/ta-p/3132434