Unity 5 - external calls getting NU tone

Unanswered Question
Jun 22nd, 2009


I have an issue where external calls to an IP Phone are failing when that tries to route to voicemail.

Internally - calls route fine and voicemail works. Externally - calls come into the system on an E1 - get forwarded on busy or no answer to Unity and the end caller gets an NU tone. In Call viewer in Unity - you can see the call hitting the system twice in quick succession with a duration of 0 or 1 second.

Here is a Q931 debug:

Jun 22 14:32:05.416: ISDN Se0/0/0:15 Q931: RX <- SETUP pd = 8 callref = 0x5FB8

Sending Complete

Bearer Capability i = 0x9090A3

Standard = CCITT

Transfer Capability = 3.1kHz Audio

Transfer Mode = Circuit

Transfer Rate = 64 kbit/s

Channel ID i = 0xA98385

Exclusive, Channel 5

Progress Ind i = 0x8581 - Call not end-to-end ISDN, may have in-band inf o

Calling Party Number i = 0x1083, '4477165403999'

Plan:Unknown, Type:International

Called Party Number i = 0x81, '2997'

Plan:ISDN, Type:Unknown

Jun 22 14:32:05.444: ISDN Se0/0/0:15 Q931: TX -> CALL_PROC pd = 8 callref = 0xD FB8

Channel ID i = 0xA98385

Exclusive, Channel 5


Jun 22 14:32:05.616: ISDN Se0/0/0:15 Q931: TX -> ALERTING pd = 8 callref = 0xDF B8

Progress Ind i = 0x8188 - In-band info or appropriate now available

Jun 22 14:32:06.308: ISDN Se0/0/0:15 Q931: TX -> DISCONNECT pd = 8 callref = 0x DFB8

Cause i = 0x80AF - Resource unavailable, unspecified

Any ideas? I've looked at DSP resources, alternate extensions, rebooting the voice gateway, rebooting Unity, etc......!!

The gateway is a 2821. The IOS is 12.4-15T8 advipservices.



I have this problem too.
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Jaime Valencia Mon, 06/22/2009 - 13:03

MGCP or H323??

That error is usually because codec issues, what codec is Unity configured for and what codec the dial-peers or location?



if this helps, please rate

davidme Mon, 06/22/2009 - 13:22

H323 gateway.

Dial peers are set to use G711u as preference 1. Unity is also set to use that as are the regions.

Jaime Valencia Mon, 06/22/2009 - 13:36

Any errors in unity's App Log for those calls??



if this helps, please rate

I've seen this before when using UCM 5.1 and Unity Connection 2.0. The fix was as follows:

Choose Service > Service Parameters and click CallManager.

Scroll down to Disable Alerting Progress Indicator and set this parameter to True.

Full details at this link:


This fixed my problem on UCM 5 but I now have the same problem with UCM 7 and Unity Connection 7 - unfortunately my previous fix hasn't cured it this time.


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