CUCM || Forward No Answer Timeout

Flo.Matalis · ‎08-13-2023

CUCM v14 SU2

Forward No Answer Timer:	This parameter specifies the seconds to wait before forwarding the unanswered call to the Call Forward No Answer destination, if specified. Make sure the value that is specified in this parameter is less than the value that is specified in the T301 Timer parameter. If the value in the Forward No Answer Timer parameter is greater than the value that is specified in the T301 Timer parameter, the call does not get forwarded and the caller receives a busy signal.
	This is a required field.
	Default: 12
	Minimum: 1
	Maximum: 300
	Unit: sec

Hi experts, I'm a bit confused.

Our customer is asking what will happen after 12 seconds of ring?

When I tested it, it just kept on ringing. Customer wants that after 12 seconds, call will get a busy tone.

I tried to tick the voicemail boxes (although extension does not have a VM box) and indeed after 12 seconds, the call got a busy tone.

Do we need to tick the voicemail boxes to make this working? or is this how CUCM behaves? I had this impression all along that this after 12 seconds, I do not need to tick the VM box, call should get a busy tone.

Please correct if my understanding is wrong. Thanks.

Jonathan Schulenberg · ‎08-13-2023

CUCM is behaving correctly; a DN without a call forward condition set will continue to ring. There is probably a maximum alerting duration timer in Service Parameters but I don’t have a working system in front of me to look for you.

I would not recommend enabling a call forward condition that will intentionally cause call failures; that will pollute your logs (and CDRs), making it more difficult to find and troubleshoot real problems in the future. Look for the service parameter or, if you have CCX / IP IVR, create an Application to play reorder and forward to that instead.

Roger Kallberg · ‎08-13-2023

As stated in the description “This parameter specifies the seconds to wait before forwarding the unanswered call to the Call Forward No Answer destination, if specified” the parameter does not have anything to do with playing a busy signal once the time set have passed. AFAIK CM doesn’t have a way to play a busy tone after a period of time, it only plays a busy tone when the extension is engaged in the number of calls specified in the busy trigger on the directory number.