Voice hunt-group doesn't dial final destination with CIPC phones as members

[NISSA_2]

In the example below on a UC520, if I add any extension such as 110 which uses an IP Communicator phone, all the extensions ring, but the final destination will not be dialed and the call goes silent but remains connected.  If I remove 110 (CIPC phone), or if I have the user close their CIPC, the final destination is dialed.  I've confirmed this behavior by adding and removing three different CIPC phone extensions to three different voice hunt-groups.

Any idea why hunt groups fail with the addition of a CIPC phone to it?

voice hunt-group 1 parallel
final 913125551212
list 102,105,110
timeout 16
pilot 511

ephone-dn  16  dual-line
number 110 no-reg primary
label 110
description Dave Sutton
name Dave Sutton
call-forward busy 399
call-forward noan 399 timeout 10
corlist incoming user-uscallsonly
translation-profile incoming CallBlocking

ephone  7
device-security-mode none
video
mac-address 0024.1DD9.3454
ephone-template 16
max-calls-per-button 2
username "asmith" password 123
type CIPC
button  1:16

[NISSA_2]

I have a workaround, but not a resolution.  If I set the timeout on the hunt-group to 9 or less, the final destination is dialed.  A timeout of 10 or above, with a CIPC client added to the hunt-group, prevents the final destination from being dialed.  I have tried with Cisco IPSec VPN client and a Cisco SSL VPN client and have the same behavior with both.  The VPN sessions terminate to a Cisco ASA 5510 firewall.

[Cristian Zaharia · Accepted solution]

You are close... The CFNA on the ephone-dn 16 has to be higher than timeout under hunt group (16 secs in your case).

Take care.

[NISSA_2]

Thank you. That fixed the issue I was having.  Apparently the SPA525G phone works regardless of the CFNA timeout being set lower than the hunt group timeout, however, the hunt group final destination didn't work with the CIPC phones unless the CFNA was higher than the hunt group timeout as you indicated.