Deploying UM and OCS 2007 R2 Integration

If you want to implement OCS 2007 R2 or later into your Exchange 2010 UM, your environment should consider the following requirements:

• One or more OCS 2007 R2 Front-End servers.
• At least one OCS 2007 R2 Mediation server connected to your PBX or phone system.
• UM server roles require a digital certificate that is enabled for UM service on that server.
• One or two phone numbers per OCS Location Profile—at least one for Subscriber Access and optionally one for an UM auto attendant. Particularly if you want to connect multiple office locations, you should consider at least a subscriber access number that is in the local phone range, but you can use a single UM auto attendant for the company.

Follow these steps to install OCS 2007 R2 integration for UM:

1. Create a UM dial plan for each of your available OCS Location Profiles:
   1. The dial plan name should, for example, include information about Exchange UM and only include characters supported by an OCS 2007 R2 Location Profile (such as no spaces).
   2. URI Type = SipName
   3. VoIP security = Secured or SIPSecured (OCS 2007 does not support unsecured VoIP security!)

   Note

   Make sure that your Office Communicator client encryption level reflects the VoIP security setting. If you configure VoIP Security as SIP Secured, you need to set it either to Rejected or Optional. If you use Secured as VoIP Security level, it must be either Required or Optional.

2. Configure your UM dial plan(s) with the correct OCS Location Profile Subscriber Access phone number.
3. Associate the UM server with the UM dial plans and make sure Startup Mode is Dual. If Startup Mode is changed, you need to restart the Microsoft Exchange UM service.
4. Run the ExchUCUtil.ps1 script found in the \Scripts folder. The script will perform the following tasks:
   1. Create one UM IP gateway for each OCS 2007 Enterprise Pool
   2. Create a UM hunt group for each UM IP gateway with their respective Pilot Identifiers
   3. Grant OCS 2007 servers permission to read Exchange UM objects in Active Directory
5. Use the Set-UMIPGateway cmdlet to configure the Port parameter of every created IP gateway to port 5061. You also use this cmdlet to disable outbound calling for all but one UM IP gateway. This is usually the gateway that is likely to handle the most traffic.
6. Run the Get-UMDialPlan -Id |flPhoneContext cmdlet in EMS and remember the PhoneContext property—you'll need to create an OCS Location Profile with that exact name.
7. Create and configure required UM auto attendant(s). Assign them the correct UM dial plan and the access phone number from the OCS Location Profile.
8. On your OCS 2007 R2 Front-End server, create an OCS Location Profile in OCS 2007 R2 for the UM dial plan you created that matches the PhoneContext name.
9. Run the OcsUMUtil.exe tool found in the C:\Progam Files\Common Files\Microsoft Office Communication Server 2007 R2 folder. The tool will verify that OCS Location Profile and UM dial plan names match and allow you to create contacts for your Subscriber Access as well as auto-attendant access numbers.
   
   
   
   
   Notes from the Field—Unified Messaging Transitioning and Extension Dialing
   
   Gary A. Cooper
   Senior Systems Architect, Horizons Consulting, Inc., United States
   Within our organization, we had been utilizing Exchange Server 2007 UM in conjunction with Office Communication Server 2007 R2. This solution worked well, but we required the new features in Exchange Server 2010 UM—specifically RMS-protected Voicemail and Voicemail Preview. When we originally configured Exchange Server 2007 UM, we did not have enough Direct Inward Dial (DID) numbers for each mailbox that was UM-enabled, so we instead configured Exchange Server 2007 UM to use the auto attendant to answer all inbound calls and then to prompt the caller to select the appropriate person to contact. This worked well until we introduced Exchange Server 2010 and DID numbers.
   
   
   To implement Exchange Server 2010, we had to create a new dial plan for OCS to route properly to the new UM server. This now forced each user to have two new EUM address entries after we moved their mailboxes to Exchange Server 2010 and migrated their UM to Exchange Server 2010 UM (by removing their old UM settings and re-provisioning them).
   
   
   • EUM: FirstName.LastName@Contoso.com;phone-context=
   • eum:;phone-context=
     
     
   In testing, what we found was that if a call came into OCS for a mailbox we had already moved to Exchange 2010 UM, the main number would be answered by the auto attendant in Exchange Server 2007 UM; then, when the older UM server tried to route the caller to the Exchange 2010 UM server, it would error and tell the caller "The call has failed, please press '0' (zero) for the operator or dial someone by name or extension to reach them directly." If the caller tried to dial by name or extension number to mailboxes still on Exchange Server 2007 UM, it worked without issue. Behind the scenes, Exchange UM couldn't find the migrated mailbox and would route the call back to OCS 2007 R2, which would route it back to Exchange UM, and so on, and eventually the call failed and the caller was dropped.
   
   
   In working with Product Support Services, we determined that Exchange 2007 was still looking for the proxy address for its dial plan in the following format:
   
   
   • eum:;phone-context=
     
     
   We determined that when the caller entered the extension (such as - 204), Exchange Server 2007 UM would search for the user in the current dial plan (the dial plan associated with the auto attendant that answered the call)—in this case the Exchange 2007 Sip_Name dial plan. It did this search by constructing the EUM address (204; phone-context=.< Exchange 2007 Dial plan GUID>) and then searching all Active Directory users to check whether any user had this stamped in their proxy addresses. However, the migrated mailbox that has been moved to Exchange 2010 UM-has been provisioned on the new Exchange 2010 Sip_Name dial plan, so it no longer has the Exchange 2007 proxy address, and so the user object is not located.
   
   
   The solution we ended up implementing was to add the legacy EUM proxy address back to the mailbox object, thus enabling extension dialing from both Exchange 2007 and Exchange 2010 UM services.

Integrating OCS 2007 R2 in Exchange 2010 Architecture

Exchange 2010 UM completes the offering of OCS 2007 R2 with a voice mail solution based on messaging. This requires a tight integration between OCS 2007 R2 and Exchange 2010 UM. Together with the integration of IM in OWA, OCS 2007 R2 can be described as being fully connected to Exchange Server 2010, as shown in Figure 1.

 

Figure 1: OCS 2007 R2 integration in Exchange 2010 architecture

The UM role communicates to the OCS Mediation server using the OCS Pool Name and thus contacts the OCS Front-End server. All signaling communication (SIP) and the voice stream (RTP) pass the OCS Front-End server.

When Office Communicator clients access their voice mail mailbox, they also do not directly contact the Exchange UM server role. Their communication is also handled by the OCS Front-End server.

Note

For more details about the communication between OCS 2007 R2 and UM, you can access the Office Communications Server 2007 R2 Workload Architecture Poster athttp://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=af2c17cb-207c-4c52-8811-0aca6dfadc94.

Office Communication Server 2007 R2 Integration

Exchange Server 2010 UM provides OCS 2007 R2 with the voice mail feature, and OCS 2007 R2 can make presence information and instant messaging features available to your OWA users. You can also configure an automatic switchboard for your OCS 2007 R2 voice-enabled users using an UM auto attendant.

UM can also utilize an existing IP PBX that is configured with OCS 2007 R2—you do not need additional hardware to connect UM to your PBX if OCS 2007 R2 is installed already. Thus any PBX configuration can be managed from the OCS 2007 R2 side, and does not need to be configured again in Exchange 2010.

OCS 2007 R2 also provides other features that integrate into UM:

• Instant messaging The OCS 2007 R2 client provides instant messaging (IM) functionality that the OCS hosts. The solution provides IM features, such as group IM, and extends the internal IM infrastructure to external IM providers. You can implement IM directly into OWA.
• Presence information OCS 2007 R2 tracks presence information for all OCS users and provides this information to the OCS 2007 R2 client and other applications, such as Outlook 2007. You can implement presence information directly into OWA.
• Web conferencing OCS 2007 R2 can host on-premise conferences, which you can schedule or reschedule, and they can include IM, audio, video, application sharing, slide presentations, and other forms of data collaboration.
• Audio conferencing Users can join OCS 2007-based audio conferences using any desk or mobile phone. When connecting to an audio conference using a Web browser, users can provide a telephone number that the audio-conferencing services calls.
• VoIP telephony Enterprise Voice enables OCS 2007 R2 users to place calls from their computers by clicking an Outlook or Communicator contact. Users receive calls simultaneously on all their registered user endpoints, which may be a VoIP phone, a mobile phone, or an OCS 2007 R2 client. The OCS 2007 R2 Attendant is an integrated call-management client application that enables a user, such as a receptionist, to manage many conversations simultaneously.
• Response Group service This service enables administrators to create and configure one or more small response groups for routing and queuing incoming phone calls to one or more designated agents. Typical scenarios include an internal help desk or customer-service desks.

Notes from the Field—OCS 2007 R2 Integration: Extension Numbers

Korneel Bullens
Team Coordinator Unified Communications, Wortell, Netherlands

One of the things I am always asked about is when deploying OCS Enterprise Voice as PBX replacement; the users still require an extension number. When you configure the UM dial plan for OCS connectivity, you select SIP dial plan as the URI type and you still need to configure the number of digits in extension numbers for the UM dial plan. Many of the administrators I talk to would not expect to be asked for an extension number in an OCS- and UM-only scenario.

When you think about it, it's quite logical. You need a unique identifier when someone calls his voice mail from outside the company, and needs to select his own voice mail box. This is when the extension number comes into the game. You are free to assign your own extension numbers, just make sure when you create the UM dial plan, the amount of digits suits your needs. If you deploy 120 users for UM, use only three digits. Fewer digits mean fewer numbers to remember for your users.