Applies to: Exchange Server 2007 SP3, Exchange Server
2007 SP2, Exchange Server 2007 SP1
Topic Last Modified: 2007-08-28
Microsoft Exchange Server 2007 Unified Messaging can use the Microsoft Office Communications Server 2007 platform to combine voice messaging, Instant Messaging (IM), enhanced presence, audio-video conferencing, and e-mail into a familiar, integrated communications experience. This Microsoft unified communications solution offers a brand new way to communicate that offers the following benefits:
- Enhanced presence notifications across a variety of
applications that keep users informed of the availability of
- Integration of IM, voice messaging, conferencing, e-mail, and
other communication modes that enable users to select the mode that
is most appropriate for the task. Users can also switch from one
mode to another as needed.
- Availability of communications alternatives from any location
where an Internet connection is available.
- A smart client (Microsoft Office Communicator 2007)
for telephony, IM, and conferencing.
- Continuity of user experience across multiple devices.
This topic discusses how Exchange 2007 Unified Messaging and Office Communications Server 2007 can be deployed together to provide voice messaging, Instant Messaging (IM), enhanced presence, audio-video conferencing, and e-mail into an integrated communication experience for users in your organization.
|To use the features described in this topic, Microsoft Exchange Server 2007 Service Pack 1 (SP1) must be installed on the computers that have the Unified Messaging server role installed.|
All Office Communications Server 2007 topologies support Enterprise Voice. Enterprise Voice is an implementation of IP telephony that uses Session Initiation Protocol (SIP) for signaling and Realtime Transport Protocol (RTP) for voice messaging. SIP is an industry standard, application layer signaling protocol for starting, controlling, and ending communication sessions in an IP-based network. SIP is formally described in the International Engineering Task Force (IETF) reference specification RFC 3261.
In Office Communications Server 2007, SIP is used for IM, conferencing, presence subscriptions, video, and voice messaging. SIP enables Enterprise Voice clients to provide a common user experience across all these communication modes. Enterprise Voice uses RTP for media. Like SIP, RTP is an IETF standard. It defines a packet format for carrying audio and video over IP networks.
When a user places a call from an Enterprise Voice client to a Public Switched Telephone Network (PSTN) destination, the call moves through the Enterprise Voice infrastructure as follows:
- The user places a call from an Enterprise Voice client by
dialing the number or by clicking the name of a contact in
Office Communicator or Microsoft Office Outlook.
- The Office Communications Server 2007 server normalizes
the telephone number to E.164 format, and then uses the routing
rules that are based on location profile and user policy
to direct the call to the correct Mediation Server.
- The Office Communications Server 2007 Mediation Server
performs any necessary media translation and routes the call to the
- The IP gateway applies local dialing rules or Private Branch
eXchange (PBX) dialing rules and passes the call to the PSTN, PBX,
or IP PBX.
The following figure illustrates a simple Unified Messaging and Office Communications Server 2007 topology.
Exchange 2007 Unified Messaging and Office Communications Server 2007 Simple Topology
Office Communications Server 2007 Overview
Office Communications Server 2007 Enterprise Voice takes advantage of the Unified Messaging infrastructure to provide voice mail, subscriber access, call notification, and auto attendant services. These include the following:
- Phone number normalization Phone number
normalization translates number strings that are entered in various
formats into a single standard format. Normalization rules specify
how to convert telephone numbers that are dialed in various formats
to standard E.164 format.
- Location profiles A location profile is
a named set of normalization rules that translates telephone
numbers for a location to a single standard (E.164) format for
telephone authorization and call routing. The name of each location
profile must match the Fully Qualified Domain Name (FQDN) of its
corresponding Exchange 2007 UM dial plan.
- Phone usage records Phone usage records
provide a quick, easy way to assign call permissions to users. To
enable phone usage records to function correctly, you must assign a
voice policy for the call to be correctly routed to the voice
- Voice policies Enterprise Voice
policies are collections of phone usage records that are assigned
to one or more users. Most organizations will have multiple voice
policies. Typically, organizations have a global policy that
applies to all users and special policies that are applied on a
- Call routing The core routing
components for Office Communications Server 2007 are the
Inbound and Outbound Routing Components, as follows:
- Inbound Routing Component The Inbound
Routing Component handles incoming calls largely according to
preferences that are specified by users on their Enterprise Voice
clients. Users specify whether unanswered calls are to be forwarded
or logged for notification.
- Outbound Routing Component The Outbound
Routing Component handles calls that are placed by Enterprise Voice
users either to telephone numbers that are owned and managed by the
enterprise or to telephone numbers on the PSTN or mobile networks.
When an enterprise user places a call, the Outbound Routing
Component looks up the target number in the Realtime Communication
(RTC) database. If the dialed number matches a SIP Uniform Resource
Identifier (URI) for an enterprise user, the call is routed through
all SIP endpoints for that user.
- Inbound Routing Component The Inbound Routing Component handles incoming calls largely according to preferences that are specified by users on their Enterprise Voice clients. Users specify whether unanswered calls are to be forwarded or logged for notification.
- Services The setup routing for
Office Communications Server 2007 installs services that
provide support for voice messaging with Exchange 2007 Unified
Messaging, including the following:
- Translation Service The Translation
service is the application that is responsible for translating the
dialed number into an E.164 number based on the normalization rules
that are defined by the administrator.
- Enterprise Services Enterprise Services
performs reverse number lookup on the target telephone number of
each incoming call, matches that number to the SIP URI of the
destination user, and sends the call to that user’s SIP
- User Replicator The User Replicator
extracts user telephone numbers from the
Active Directory directory service and writes them to
tables in the RTC database, where they are available to Enterprise
Services and the Address Book Service.
- Address Book Service The Address Book
Service normalizes enterprise user telephone numbers that are
written to the RTC database to E.164 format to provision user
Contacts in Communicator 2007.
- Translation Service The Translation service is the application that is responsible for translating the dialed number into an E.164 number based on the normalization rules that are defined by the administrator.
To download the reference and Help documentation for Office Communications Server 2007, see Office Communications Server and Client Documentation Rollup.
Exchange 2007 Unified Messaging
The Unified Messaging server role is one of several Exchange Server 2007 server roles that you can install and configure on a computer that is running Exchange 2007. For Enterprise Voice users, Unified Messaging (UM) combines voice messaging and e-mail messaging into a single store that can be accessed from a telephone or a computer. Unified Messaging and Office Communications Server 2007 work together to provide voice mail, subscriber access, and auto attendant services to Enterprise Voice deployments, including the following:
- Voice mail Voice mail includes
answering an incoming call on behalf of a user, playing a personal
greeting, recording a message, and submitting it for delivery to
the user’s Inbox as an e-mail message. Notification of unanswered
calls is sent to the user's Outlook
and Microsoft Outlook Web Access Inboxes.
The subject and priority of calls can be displayed in a way that
resembles the way they are displayed for e-mail.
- Subscriber access A subscriber is an
internal business user or network user who is enabled for
Exchange 2007 Unified Messaging. Subscriber access is used by
users to access their individual mailboxes to retrieve e-mail,
voice messages, contacts, and calendaring information. Outlook
Voice Access is the new Exchange 2007 Unified Messaging
feature that lets subscribers access their Exchange 2007
mailbox. Subscriber access enables an Enterprise Voice user to
access voice mail, calendar, and contacts from a telephony
interface. A subscriber access number is configured by the
Exchange 2007 administrator on a Unified Messaging dial
plan. For more information about Outlook Voice Access, see
Unified Messaging Subscriber Access.
- Auto attendant In telephony or Unified
Messaging environments, an automated attendant or auto attendant
menu system transfers callers to the extension of a user or
department without the intervention of a receptionist or an
operator. In many auto attendant systems, a receptionist or
operator can be reached by pressing or saying zero. The automated
attendant is a feature in most modern PBXs and Unified Messaging
solutions. For more information about auto attendants in
Exchange 2007 Unified Messaging, see Understanding Unified
Messaging Auto Attendants.
For more information about Exchange 2007 Unified Messaging, see Unified Messaging.
There are four user scenarios in which Office Communications Server 2007 and Exchange 2007 Unified Messaging can be used together. These are:
- Call notification User 1 calls User 2.
User 2 does not answer the call. User 1 hangs up. User 2 receives
an e-mail message in their Exchange 2007 mailbox that User 1
called. Call notifications are also sent when an inbound call is
forwarded. User 1 calls User 2. User 2 sets call
forwarding to User 3. User 1 calls User 2. The call
is forwarded to User 3, and User 2 receives a call
notification that the call was forwarded.
- Leave a voice mail message User 1 calls
User 2. User 2 does not answer the call. Because User 2 has not
configured call forwarding to another telephone number, the call
from User 1 is diverted to the voice mail for User 2. User 1 is
invited to leave a voice message for User 2. The voice mail
greeting that was previously recorded by User 2 is played, inviting
User 1 to leave a voice message for User 2. User 2 receives a voice
mail message recorded by User 1.
- Subscriber access User 2 dials in to a
subscriber access number and accesses their Exchange 2007
mailbox to check for voice messages. User 2 can listen to their
e-mail or voice mail messages or access their calendar. After
listening to the voice message from User 1, User 2
decides to return the call from User 1. User 2 accesses the
options menu and uses the call back option to place a call to User
- Auto attendant User 1 does not know the
extension number for User 2. User 1 dials in to a telephone number
that is configured on a UM auto attendant. The welcome greeting and
prompts that are configured on the auto attendant are played to
User 1. User 1 uses the directory search feature to locate User 2
in the directory and places a call to the extension number for User
Note: Both subscriber access and those auto attendant services offered by Exchange 2007 Unified Messaging require users to dial specific telephone numbers. These numbers must be routable by Enterprise Voice. This means that each number must be mapped to a SIP address. Office Communications Server 2007 can route the SIP address to an address that is configured on the server that has the Exchange 2007 Unified Messaging server role installed.
Exchange 2007 Unified Messaging Active Directory Objects
Exchange Unified Messaging Active Directory objects enable Exchange 2007 Unified Messaging to integrate with the Office Communications Server 2007 Enterprise Voice infrastructure. To successfully deploy Exchange 2007 Unified Messaging in your organization, you must fully understand the relationship between each of following UM Active Directory objects and their counterparts in Enterprise Voice:
- Unified Messaging Dial Plan object A UM
Dial Plan object is the basic unit of configuration in Exchange
Unified Messaging. A UM dial plan can be of the following
types: Telephone Extension, SIP URI, or E.164. When Exchange
Unified Messaging is deployed with Office Communications Server
2007, the dial plan type is always SIP URI. Users in a UM dial plan
reach all other users in the plan by using SIP URIs or SIP
addresses. Each SIP address must be unique within a given SIP URI
dial plan. Each dial plan must correspond to an Enterprise Voice
location profile. The name of each location profile must match
the forest FQDN of the SIP URI dial plan.
- Unified Messaging IP Gateway object A
Unified Messaging IP Gateway object is a logical representation of
a physical IP gateway or SIP-enabled IP PBX. The UM IP gateway
object logically represents each Office Communications Server 2007
pool and front end server as if it were a physical IP gateway. Each
UM IP Gateway object encapsulates configuration elements that are
related to the corresponding pool or server. After a UM IP Gateway
object is created, it is associated with one or more UM hunt
- Unified Messaging Hunt Group object The
UM Hunt Group object associates a UM IP gateway with a UM dial
plan. By creating multiple UM Hunt Group objects you can associate
a single UM IP gateway with multiple UM dial plans and, therefore,
with multiple Enterprise Voice location profiles.
For more information about the Active Directory objects that are included in Exchange 2007 Unified Messaging, see Overview of Unified Messaging Active Directory Objects.
The following figure illustrates the relationships between Exchange 2007 Unified Messaging objects and Office Communications Server 2007 objects.
Unified Messaging and Office Communications Server 2007 objects and their relationships
Exchange 2007 Unified Messaging (UM) combines voice messaging and e-mail messaging into a single messaging infrastructure. Office Communications Server 2007 Enterprise Voice takes advantage of the Unified Messaging infrastructure to provide voice mail, subscriber access, call notification, auto attendant services and other enhanced features that include voice messaging, Instant Messaging (IM), enhanced presence, audio-video conferencing, and e-mail into an integrated communication experience for users in your organization. Implementing these services requires integrating Unified Messaging and Office Communications Server 2007 in a shared Active Directory topology. For more information about the configuration steps that are required to correctly deploy and integrate Exchange 2007 Unified Messaging and Office Communications Server 2007, see Configuring Unified Messaging and Office Communications Server 2007.
|Users who are associated with a SIP URI dial plan cannot receive incoming faxes. This is because incoming voice and fax calls are routed through a Mediation Server computer and faxing is not supported when you are using a Mediation Server.|
To download the reference and Help documentation for Office Communications Server 2007, see Office Communications Server and Client Documentation Rollup.
For More Information
- For more information about how to configure Unified Messaging
and Office Communications Server 2007 integration, see Configuring Unified
Messaging and Office Communications Server 2007.
- For more information about Unified Messaging dial plans, see
Unified Messaging Dial Plans.
- For more information about Unified Messaging IP gateways, see
Unified Messaging IP Gateways.
- For more information about Unified Messaging hunt groups, see
Unified Messaging Hunt Groups.