Consider the following scenario:
- You try to join a conference call which is hosted on a Microsoft Office Communications Server 2007 R2 from a Public Switched Telephone Network (PSTN) telephone.
- The conference call is created by using the Conferencing Add-in for Outlook or by using Communicator Add-in for Outlook.
- You dial the Conferencing Auto Attendant (CAA) access number, and then you enter the conference ID.
- You wait for several minutes.
This issue occurs because the Unified Communications Managed API (UCMA) does not reply to an UPDATE message.
To resolve this issue, install the following cumulative update:
2501720 Description of the cumulative update for Office Communications Server 2007 R2, Unified Communications Managed API 2.0 Core Redist 64-bit: March, 2011
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to"
Article ID: 2489817 - Last Review: Feb 14, 2017 - Revision: 1
Microsoft Office Communications Server 2007 R2 Enterprise Edition, Microsoft Office Communications Server 2007 R2 Standard Edition