Outlook Voice Access keeps prompting to enter extension with CUCM

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Environment:

  • Cisco Unified Communications Manager -CUCM
  • Exchange 2013 Unified Messaging
  • Cisco Phone 1 – Common Area Phone No Voicemail Enabled
  • Cisco Phone 2 – User Extension Voicemail Enabled

Issue:

When are user presses the voicemail button on Cisco Phone 1 it connects to Outlook Voice Access (OVA) and prompts “To connect to your mailbox enter your extension” to check voicemail, when you enter the extension there is a quick ringing and then you hear “To connect to your mailbox enter your extension” again and keep looping.

However when you perform press the Voicemail button Cisco Phone 2 it recognizes the user and says their name , pressing the * key  allows me to reach the “To connect to your mailbox enter your extension” I then enter another extension and it accepts extension and prompts to enter the PIN.

We ran some tracing on the CUCM and we found that in the INVITE the REFERRED-BY information Extension entered by caller is provided by the Exchange UM 2013 server

REFERRED-BY header REFERRED-BY: <sip:domain.com-ex01.domain.com;v=1.0;extension=5551212;c=ms-ova-data>
The CUCM fails to use the REFERRED-BY extension in the INVITE that is sent to the Exchange 2013 UM server and then it prompts you to enter the extension again.

Resolution:

The guys working on the CUCM found the below articles, one is not necessarily our issue but we decided to try it out.

Article 1:

CUCM ignores REFERRED-BY, due a design limitation, we have an enhancement bug open for it which is CSCtf35144 (https://tools.cisco.com/bugsearch/bug/CSCtf35144/?reffering_site=dumpcr), since CUCM SIP trunk does not support RFC3515 completely, supporting incoming REFERs (both in-dialog and out of dialog) and we use only Refer-To and Replaces header in the incoming REFER message (to route the call), however not supporting Referred-By Header. This has been fixed on CUCM 11.0 version

Article 2:

Bug Search

CSCuw37904

Help  |  Feedback

Need to enter the password twice exchange 2010,

CSCuw37904

Description

Referred by header is not being populated in the outbound Invite when MTP allocation happens.
This caused to enter the password twice for exchange 2010.

Symptom:
CSCtf35144 add the refer by header only for non MTP calls. When there is an allocate MTP request we wait for its Allocation and OLC from the MTP device before we send the Invite out. It is at this point SIPCdpc fails to check if Call Control gave a refer by URI in the CcSetupReq message

Conditions:
When the customer access the voicemail form a unkwon number has to enter the password twice, if dial form a number valid on the CUCM works fine

Workaround:
to enable Best effort early offer on the Sip trunk that would ensure that MTP is not mandatory for every calls, Or you can disable Early offer.

Further Problem Description:
CSCtf35144 add the refer by header only for non MTP calls. When there is an allocate MTP request we wait for its Allocation and OLC from the MTP device before we send the Invite out. It is at this point SIPCdpc fails to check if Call Control gave a refer by URI in the CcSetupReq message

Here are the steps we performed in order to resolve the issue:

  1. First the CUCM was upgraded 10.5(2.12900) to 10.5(2.13900.12) <– This release fixes the issue when MTP is not enabled and set as best effort, it appears that it is fixed in version 11.0 when MTP is enabled but it has not been validated.
  2. On both the SIP Trunks for Exchange UM CAS and MBX
    1. Browse to your CUCM configuration
    2. Select: Device –>Trunk
    3. Uncheck Media Termination Point Required , Click Save
      1. Reset and Restart both SIP Trunks.CUCMExchangeUMCAS CUCMExchangeUMMBX
  3. Select Device –> Device settings –> SIP Profile
  4. Early offer support for voice and video calls* is set to: Best Effort (no MTP inserted), Click SaveCUCMExchangeUMSIPProfile

Now from Cisco Phone 1 we dialed the Exchange UM Pilot number and entered the extension it now used the REFERRED-BY field in the current format and we were prompted to enter the PIN number.

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3 comments on “Outlook Voice Access keeps prompting to enter extension with CUCM

  1. Thanks a lot for this great post. We were facing the same issue and this post really helped to fix our long running issue with Ex2013. Thanks again.

  2. I have the same issue and just upgraded to CUCM 11.0, I have tried the above which worked treat. I now have a problem with external calls not being able to dial-in 🙁 rolled back changes for now

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