CUCM 9.1.1a CFA override by CFNA

[bernhardczapp]

Hello,

we upgraded a Cluster from 6.1.4 to 9.1.1a.

Now I have got a strange behavior using call forward.

Situation A

Phone A CFA to phone B

Phone B CFNA to phone A

Someone calls phone A or B:

Phone B rings; CFNA timeout occurs -> Phone A rings (CFA is overridden)

Situation B

Phone A CFA to phone B

Phone B CFB to phone A

Phone B is busy; someone calls phone A or B:

Phone A rings (CFA is overridden)

CFA = call forward all

CFNA = call forward no answer

CFB = call forward busy

Especially Situation A seems strage to me.

Does anybody know a workaround for this? Maybe the "CFA Destination Override" Service Parameter?

Thanks,

Bernhard

[Aaron Harrison]

Hi

That behaviour would match the behaviour I would expect if 'CFA Destination Override' was set to 'Enabled'. Is this the case on your system?

CFB would always 'override' CFNA - if the phone is busy then it cannot time out.

Regards

Aaron

[bernhardczapp]

I have tested with "CFA Destination Override" Service Parameter Disabled and Enabled.

This doesn't change anything.

Maybe you got me wrong?

CFB and CFNA override the CFA!

[paolo bevilacqua · Accepted solution]

Seems to me that in both cases the system is breaking a call routing loop as soon it is detected (call forwarded to where it comes from).. I consider that proper behavoir, for sure some may not agree.

[Rob Huffman]

Hi Bernhard,

I'll just add this note to the good tips from my friends Aaron & Paolo (+5 each)

It sounds like you may be hitting this bug that first appeared in

CUCM 9.1.1;

Manage an application caused CFA loop via "Forward Maximum Hop Count"

CSCug04494

Description

Symptom:Call Forward All gets ignored by CUCM

Conditions:CUCM  ignores the CFA request when it recognizes a loop. This loop is  intentional and should not be broken by CUCM on certain occasions.

Workaround:None.

Known Affected Releases:

(1)

9.1(1.10000.1)

Known Fixed Releases:

(0)

Cheers!

Rob

[bernhardczapp]

This might be the issue.

I guess I will have to open a case.

Thanks!

[bernhardczapp]

Answer:

The system works as it should work.

The loop breakout was introduced in CUCM 7.0(1). Futher desciption of this 'feature' can be found in the system guide of the corresponding CUCM version.

For example page 522 of system guide for CUCM 9.1 (http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/9_1_1/ccmsys/CUCM_BK_C5565591_00_cucm-system-guide-91.pdf)