• Illustration: Accessing Voice Mail Using Outlook 2007
• Illustration: Unified Messaging Architecture: Taking the Call
• Illustration: Retrieving E-Mail and Voice Mail Using a Phone

New unified messaging (UM) capabilities in Exchange Server 2007 improve on traditional voice-mail systems by placing voice mail, faxes, and e-mail into a single inbox. Users can access their unified inbox—as well as their calendar, contact lists, and corporate address book—from a PC, Web client, or mobile e-mail client, as well as from a standard telephone using voice commands. However, providing users with UM capabilities involves upgrading the entire e-mail infrastructure to Exchange Server 2007, as well as the potentially complex task of interfacing with existing telephony equipment.

Advantages of the Unified Inbox

A unified inbox cuts down the number of places users need to check and helps them prioritize and organize their messages. Users who receive many voice mails and faxes in addition to e-mails will benefit greatly by being able to manage all of them from a single client interface. Furthermore, the ability to navigate e-mail messages and personal calendar entries by issuing voice commands over a standard phone and to have the information "read" back—a feature Microsoft calls Outlook Voice Access—can be useful for mobile users who may not have immediate access to a PC or who do not have their hands free to operate a personal digital assistant (PDA) or other mobile device.

For corporate IT, Exchange 2007's unified messaging features promise lower ongoing maintenance costs by consolidating e-mail, voice mail, and incoming fax services into a single system. The advantages of consolidation are greatest for organizations that currently maintain multiple voice-mail systems, such as businesses with separate voice-mail systems at each regional sales office.

Provisioning new employees is easier on an Exchange 2007—based UM system because all the information is centralized in Active Directory, eliminating the need for a separate voice-mail directory. Furthermore, Exchange 2007 UM makes it possible for administrators to apply a common set of security, retention, and backup policies to all message types. As more organizations strive to comply with potential legal discovery requests or industry-specific regulations, the ability to enforce retention policies across all communications types, including voice mail, has assumed ever greater importance.

However, despite the benefits of Exchange UM, there are several reasons for caution. First, like any competing voice-mail or unified messaging product, Exchange UM requires integration with a company's existing telephony equipment, a project made challenging by telephony's inherent complexity and the lack of standards across private branch exchange (PBX) vendors. Second, notwithstanding the many high-availability capabilities built into Exchange 2007, consolidation still means a single failure can bring down both e-mail and voice-mail services at the same time. And third, rolling out unified messaging requires deploying an Exchange 2007 infrastructure, which is more expensive than the upgrade from Exchange 2000 to Exchange 2003 was both in terms of product licensing and migration complexity.

As a result, it is unlikely that organizations will rip out working voice-mail systems and replace them with Exchange 2007 on the merits of unified messaging alone. A shift to Exchange 2007 unified messaging makes the most sense for organizations that want to replace inadequate voice-mail systems or systems at the end of their useful life, as well as organizations already sold on an Exchange Server 2007 migration because of the many other improvements in the product. After an organization has upgraded to Exchange 2007, the incremental cost of implementing Exchange 2007 UM is modest, especially compared to competing solutions.

Unified inbox and telephone access for Exchange have been available for some time from third-party vendors, such as Avaya, but only a small percentage of Exchange customers purchased and deployed the technology. Although building UM features into Exchange 2007 hurts incumbent ISV partners with competing technology, it promises to enlarge the total UM market and create opportunities for systems integrators with expertise in the area.

Handling Voice Mail and Fax

Exchange 2007 is very similar to the typical voice-mail system it replaces. Exchange 2007 also handles incoming faxes, but with some limitations.

Voice Calls

Exchange 2007 includes an Automated Attendant application to greet external callers and help them reach an extension without assistance from a human operator. It includes a directory search function as well as customizable voice menus and informational messages that can be used to provide information such as business hours, driving directions, and job opportunities. The Automated Attendant can play greetings and provide different caller options depending on whether the call comes in during business hours, after hours, or on a day designated as a holiday.

Callers can connect directly to a user's extension by number, or they can find the extension by searching the organization's directory. If the user does not answer, Exchange 2007 answers incoming calls, plays a personal greeting (or a special "out-of-office" greeting), records a voice mail, attaches it to a message, and submits the message for delivery to the user's inbox. If the caller hangs up before recording a voice mail, Exchange 2007 can provide a missed-call notification message in the recipient's inbox.

When a call originates from within the organization, Exchange 2007 uses information in Active Directory to include the caller's name and phone number in the message header. For outside calls, if the caller ID information available consists only of a phone number, Exchange will try to determine the caller's name by performing reverse lookups in the corporation's Active Directory and the user's Outlook contacts list.

By default, Exchange 2007 uses the Windows Media Audio (WMA) codec to record voice mails. Using this format, a 30-second message consumes about 40KB and an hour of voice-mail messages consumes only a few megabytes.

Exchange 2007 does not include the ability to illuminate a "message waiting" indicator light on existing PBX phone handsets. However, third-party products, such as MWI2007 from Geomant (www.mwi2007.com), can perform this function. Like most other voice-mail systems, Exchange 2007 cannot tailor voice-mail greetings or missed-call notification messages to the identity of the caller—the same rules apply to everybody. For example, Exchange 2007 can't play a different voice-mail greeting depending on whether the caller is internal or external to the organization and can't be configured to generate missed-call notification messages only when certain people call. Furthermore, Exchange 2007 is designed simply to take voice-mail messages and not to take over call-routing functions (that role is handled by Communications Server, a separate and complementary Microsoft product). For example, Exchange 2007 can't forward calls to a user's cell phone if the user doesn't answer her work line.

Incoming Fax Support, Limited Recognition

Exchange 2007 can route incoming faxes automatically to users who have their own fax numbers. If a single fax number is shared by a department or other group, however, human intervention is required. Such manual routing is made easier by Exchange 2007's Fax Reception Assistant utility, which uses limited optical character recognition (OCR) capabilities to search for a "To" line within the fax image and suggests the proper recipient.

Each fax is represented as a TIFF image and generally consumes less than 100KB per page.

Since Exchange 2007 does not perform full OCR on incoming faxes, it can't search fax contents or read faxes over the phone (using a text-to-speech engine) as it can with e-mails. Neither does it support fax sending. Office and Windows already provide basic fax sending (using a modem in a PC or a third-party Internet-based fax service), and the company says high-volume fax senders don't represent a large market opportunity. Microsoft is leaving OCR and outgoing fax functions to third parties, but none are on the market yet.

Just Another Message Type

Exchange treats voice mails, missed call notifications, and faxes as another message type, similar to e-mail, and provides similar support for policy enforcement and search.

Storage quota. All messages in a user's mailbox, regardless of type, are bound by the same storage quota policy. As in prior versions of Exchange, administrators specify thresholds for warning users that they are nearing their quota, prohibiting users from sending new e-mail messages, and prohibiting users from either sending or receiving any type of message. When a user reaches the final threshold, callers attempting to leave voice mail will hear a "mailbox full" recording.

Folders, rules, and search. Just like e-mails, voice mail and incoming faxes can be sorted into folders and processed via rules (e.g., "mark all voice mail messages from my boss with a red flag"). Furthermore, users can search on header information of voice mails and faxes, as well as notes they manually add to these messages. And finally, as with e-mails, unopened voice mails and faxes are clearly marked as unread (using bold), allowing users to keep track of which messages they've seen or heard.

Retention policies. Exchange 2007's new managed folders feature can be applied to voice mail and incoming faxes, in addition to e-mails. Managed folders, defined by administrators and automatically incorporated into users' mailboxes, enable an organization to retain particular types of messages for time periods mandated by company policy or government regulations, as well as to automatically remove unneeded content after a set period of time to free up storage space or limit legal exposure.

Delegation. Inbox access permissions apply to all message types. Giving an associate permission to view a user's inbox provides the associate access to incoming voice mails and faxes as well as e-mails and calendar information.

Telephone Access

The new Outlook Voice Access (OVA) application included with Exchange 2007 allows users to call into an Exchange 2007—based mailbox from a standard telephone. Voice prompts help users navigate through the system. Users can retrieve, listen, reply, and forward voice, fax, or e-mail messages, and listen to or change calendar information by pressing buttons on the telephone keypad or by speaking voice commands.

With the exception of PIN entry, any command that can be submitted using the telephone keypad can also be accomplished by voice command. This includes directory lookup—users can locate people in the organization's directory by pronouncing their names. If the spelling of a person's name is inconsistent with the way it is usually pronounced, an administrator can add a "phonetic name" to a user's Active Directory entry to improve directory lookup. Currently, Exchange 2007's voice-recognition engine supports English only. Although Microsoft has made no official commitments, the company hopes to ship an additional language or two in Exchange 2007 service packs, but it won't greatly expand the number of languages until the next version of Exchange.

Text-to-speech capabilities allow Exchange 2007 to read back message header information (such as the time, sender, and subject), e-mail contents (but not e-mail attachments or fax content), incoming meeting requests, and details of appointments already on the user's calendar. Currently Exchange 2007's text-to-speech engine supports approximately a dozen languages (including Brazilian Portuguese, Dutch, English, French, German, Italian, Japanese, Korean, Mandarin Chinese, Spanish, and Swedish) and automatically analyzes text within the e-mail body to determine the appropriate language for rendering.

While listening to e-mail and voice-mail messages, a user can rewind, fast forward, or pause reading; move to the next message; delete the message; and reply to a voice mail or e-mail with a voice mail. It should be noted, however, that OVA provides users access to only a single folder within a mailbox. The default is the inbox, but users can make a different folder the default. (Microsoft says that, given the constraints of a telephone keypad and voice interface, providing the ability to traverse different folders would be unwieldy.)

Users can also use keypad and voice-command interfaces to accept or decline meeting requests and manage schedules. For example, users can phone in and tell the system that they will be 15 minutes late to an upcoming meeting, cancel participation in a meeting, or clear their schedules for a certain period of time. All affected participants will automatically be notified via e-mail.

Finally, users can change voice-mail preferences by telephoning into OVA. For example, a user can record a new voice-mail greeting or change his PIN.

Customization Limited

Together, OVA and the Automated Attendant provide voice access to Exchange 2007, but they are not a general-purpose interactive voice response (IVR) application platform. Their extensibility is limited. For example, they can't be programmed to retrieve data from a database for a simple application such as allowing students to phone in to check a test grade.

For more general kinds of IVR applications, Microsoft recommends Speech Platform Services (formerly Speech Server), which will be a feature of Communications Server 2007.

PC and Mobile Access

Voice mail and faxes can be retrieved with Outlook XP or later on a PC, via a browser connected to Exchange 2007 Outlook Web Access (OWA), and on a mobile device, such as a Windows Mobile-powered Smartphone or PDA, that has Microsoft Exchange ActiveSync enabled. While similar in many respects, the experience varies slightly depending on the client software used.

Outlook 2007 and OWA 2007 with IE 6 and Later

Outlook 2007 and Exchange 2007 Outlook Web Access (OWA 2007) offers the most complete set of voice-mail- and fax-related capabilities. Outlook 2007 is the latest version of Microsoft's e-mail client software. OWA 2007 is a Web-based application included with Exchange Server that supports browser-based mailbox access using Internet Explorer (IE) versions 6 and above. With the exception of Outlook 2007's support for client-side caching, Outlook 2007 and OWA 2007 have the same features and capabilities with respect to UM. (For an illustration, see "Accessing Voice Mail Using Outlook 2007".)

Outlook 2007 and OWA 2007 add icons for voice-mail messages (a telephone) and fax (a sheet of paper) to help users quickly distinguish these new message types from e-mail and appointment requests.

For voice mails, the "From" and "Subject" fields communicate message duration as well as either a name or phone number (or "Anonymous Caller" if the caller can't be identified). Like e-mail messages, voice mails are marked with a red exclamation point if the caller marked the voice mail as urgent. Within the body of the message is a notes field where users can manually enter text that is searchable. An embedded Windows Media Player control with play, stop, pause, rewind/forward, and volume controls directs playback on the PC's speakers. This ActiveX control was included with Windows XP SP2, so most PCs should already have it installed.

Also present in the voice-mail message body is a "play on phone" field that allows the user to redirect message playback to a phone rather than to the PC's speakers. This feature is useful in public settings where privacy is required, such as at an airport. Exchange 2007 dials the play-on-phone telephone number specified and, once the call is answered, immediately starts playing the message. After the message is played, the user has the option to log onto OVA to listen to other messages over the telephone connection.

As with their voice-mail counterparts, incoming faxes have "From" and "Subject" fields that indicate the identity of the sender (if possible) and a notes field within the message body that users can type text into and later search. The Subject field also indicates the number of pages. A built-in TIFF viewer embeds the fax image within the message body itself.

Outlook 2007 and OWA 2007 also contain interfaces to allow users to set voice-mail preferences, including their PIN for logging on to OVA, default play-on-phone number, telephone access folder, and personal voice-mail greeting. (The greeting is recorded using a telephone rather than a microphone attached to the PC.)

Absent from Outlook 2007 and OWA 2007 is a seamless way for a user to respond to an incoming message with a voice-mail message. A user would have to record a message (using a sound recording application) on her PC and attach it to an e-mail message or use a regular telephone to call into OVA.

Earlier Outlook, Other Browsers Supported but Limited

While Outlook XP and 2003 can access voice mails and faxes in an Exchange 2007 user's mailbox, the experience is not as polished as with Outlook 2007 and OWA 2007. For example, when a user opens a voice mail using an earlier version of Outlook, the voice mail will appear as a file attachment. Clicking on an audio attachment will launch Windows Media player in a separate window, and the voice mail will be played over the PC's speakers. Faxes also appear as attachments. Clicking on a fax attachment will launch whatever application is registered on the system for viewing TIFF files.

The experience is similar for users who attempt to access their mailbox via OWA using a non-Microsoft browser—such as Firefox, Navigator, Opera, and Safari—or IE version 5.x or older. When OWA 2007 detects one of these browsers, it runs in a downgraded mode, often referred to as OWA 2007 Light. OWA 2007 Light shows a voice mail or a fax as a multimedia file embedded within the page displaying the message. When the user clicks on the multimedia file, browser plug-ins are used to play the voice mail on the PC or display the fax images.

Neither Outlook 2003/XP nor OWA 2007 Light supports notes or the play-on-phone option, and neither client has an interface allowing the user to set voice-mail-related preferences and settings. Users need to telephone into OVA to set voice-mail preferences, such as voice-mail greetings.

Mobile Devices

Users with phones based on Windows Mobile 5.0 or non-Windows mobile phones that have Microsoft's ActiveSync technology built in (from vendors such as Motorola, Nokia, Palm, and Sony Ericsson) can access voice mails and faxes in an Exchange 2007 mailbox. If a user's mobile device does not support WMA codecs, an administrator can configure the user's mailbox to record voice mails using GSM codecs available on many mobile devices.

Since voice mail and incoming faxes are treated exactly like an e-mail with an attached file, the mechanisms used to synchronize e-mail messages with the mobile device are also used to handle voice mail and incoming faxes. To prevent long downloads over low-bandwidth connections, users can configure their Windows Mobile devices to not download attachments automatically, or to download them only if they are smaller than a preset size limit.

Users can't employ mobile devices to set voice-mail preferences such as a personal greeting; they must dial into OVA to do so.

The Unified Messaging Server

The Exchange 2007 component that makes UM possible is the Unified Messaging (UM) Server, which can be installed on a dedicated server or on a server that is hosting other Exchange roles, such as a Mailbox server.

The UM Server is connected to the company's PBX and records voice mails, sends voice mail and faxes to users' mailboxes, and provides telephone access to mailboxes (using OVA). It also plays greetings and informational announcements and provides menu prompts and navigational instructions to callers (via Automated Attendant). (See the illustration, "Unified Messaging Architecture: Taking the Call" and "Retrieving E-Mail and Voice Mail Using a Phone".)

Gateway Required

Most customers will need a gateway between their PBXs and Exchange 2007 UM servers to convert voice calls into protocols the UM Server understands: T.38 for fax transport, and the Session Initiation Protocol (SIP) and Realtime Transport Protocol (RTP) for Voice over IP (VoIP) support. To date, the only PBX on the market that does not require a gateway is the Cisco Call Manager 5.0 IP-PBX, although Nortel has announced add-ons for its CS1000 PBXs, due before the end of 2007, that will eliminate the need for a separate gateway to Exchange. It is likely that other PBX vendors will follow in the future.

Two companies, AudioCodes and Dialogic (formerly named Eicon Networks), offer gateways certified for Exchange 2007. These appliances support a variety of PBX models from various vendors. Microsoft claims the available gateways cover more than 85% of the installed base of PBXs in North America and nearly that many in Europe.

To provide both scalability and high availability, a PBX can be connected to UM Servers via multiple gateways. For example, if a particular UM Server doesn't accept a call from a gateway (e.g., because of a connectivity problem or because the server is too busy), the gateway can be configured to try other UM servers. Conversely, if a UM Server can't establish a connection with the PBX through one gateway, it can try another.

UM Server Sizing and Scaling

The number of concurrent calls a UM Server can handle is determined by the CPU and memory in the machine. The number of concurrent calls is the sum of the following:

• Callers in the process of using the Automated Attendant or leaving a voice mail
• Users phoning into OVA or listening to voice mails via the play-on-phone feature built into OWA 2007 and Outlook 2007
• Incoming faxes in progress.

In its internal testing of Exchange 2007, Microsoft found that a generic dual-processor server dedicated to a UM Server role can handle about 100 concurrent calls. Additional capacity or fault tolerance can be achieved with additional UM Server machines. Microsoft claims that its UM system scales sufficiently to handle the largest of Exchange installations.

UM servers use little disk storage, and most of their data is replicated elsewhere. For example, UM configuration information is maintained in Active Directory, voice-mail greetings and recorded messages are stored on Mailbox servers, and Automated Attendant and OVA audio navigational prompts would typically be replicated from a folder on a file server. With the exception of voice-mail and fax messages in the process of being recorded, no critical data would be lost permanently if a UM server machine crashed.

Management and Troubleshooting Tools

As with other Exchange 2007 components, administrators use the Exchange Management Console and the new command-line-based Exchange Management Shell to configure and perform management tasks on UM Servers (e.g., setting minimum PIN length).

Exchange Server 2007 includes several UM-related troubleshooting tools. The GUI-based "Unified Messaging Test Phone" tool, which runs on a client computer and simulates a telephone call, tests the functionality of UM Servers without requiring a gateway or PBX. A separate command-line tool, which connects to a remote UM server by placing a call through a gateway, can test the full operation of a UM system. Finally, UM Servers maintain more than 100 performance counters that measure current state (such as how many subscribers are logged onto OVA), averages (such as the average voice-message size), and counts (such as the number of calls that were answered on behalf of users).

Seek Expertise of a Systems Integrator

Microsoft strongly suggests that customers interested in UM seek the assistance of a systems integrator, and for good reason. The solution involves stitching together complex components from multiple vendors. Of the 20 organizations that participated in Microsoft's Exchange 2007 Unified Messaging early adopter program, all but one relied on the assistance of certified Microsoft partners with telecommunications expertise.

Not surprisingly, careful preplanning is mandatory. Among the many issues customers need to consider are the following:

• Server and gateway sizing
• UM impacts on mailbox storage quotas and disk storage requirements
• Architecting high availability using redundant components, improved WAN Service Level Agreements (SLAs), and other means
• Which functions can be moved to Automated Attendant and which existing call applications should remain as they are
• How best to group UM users and manage them via mailbox policies
• Strategy and tools for migrating users from an existing voice-mail system to Exchange 2007, including how to straddle two different systems during a large, staged migration.

Deploying UM Servers and gateways is complex. Numerous parameters must be configured on PBXs, gateways, and UM servers for the system to work properly. In some cases, parameters need to be set consistently across different devices, often in a particular order. Given the lack of standardization and wide divergence of capabilities across PBX vendors' products, correctly configuring an organization's PBXs and associated gateways is typically one of the more difficult deployment tasks.

Resources

Microsoft's main Unified Messaging portal page is at www.microsoft.com/exchange/evaluation/unifiedmessaging/default.mspx. It includes links to white papers, demo videos, case studies, and lists of Microsoft partners offering solutions and support for Exchange Server 2007 Unified Messaging.

Information about supported PBXs and gateways can be found at www.microsoft.com/technet/prodtechnol/exchange/telephony-advisor.mspx and www.microsoft.com/technet/prodtechnol/exchange/pbx-partners.mspx.

Exchange Server 2007 documentation is available at technet.microsoft.com/en-us/library/bb124558.aspx. It can also be downloaded as a help file at www.microsoft.com/downloads/details.aspx?familyid=555F5974-9258-475A-B150-0399B133FEDE.

Detailed information about languages supported in Exchange Server 2007 is posted at www.microsoft.com/exchange/evaluation/languages.mspx.

For information about Exchange Server 2007 licensing, see "Exchange 2007 Packaging, Licensing, and Pricing" on page 3 of the Jan. 2007 Update.

Other Exchange Server 2007 features besides Unified Messaging were described in "More Than Unified Messaging Coming to Exchange 2007 Users" on page 3 of the Dec. 2006 Update, "Exchange 2007 a Boon to IT" on page 3 of the Feb. 2007 Update, and "Exchange 2007 Assists Regulatory Compliance" on page 9 of the Feb. 2007 Update.