To use the new and improved features in Exchange 2007 SP1 when you integrate Communications Server 2007 in your environment, the following requirements must be met:

• You must be running Exchange 2007 SP1 on all Unified Messaging servers in your organization.
  
• You must be running Communications Server 2007 in your organization.
  
• Exchange 2007 SP1 and Communications Server 2007 must be configured correctly.
  

To correctly plan and deploy Exchange 2007 SP1 and Communications Server 2007 in your Unified Messaging environment, you must follow the planning and deployment steps that are provided in the Microsoft Office Communications Server 2007 Enterprise Voice Planning and Deployment Guide. This guide is available at the Office Communications Server and Client Documentation Rollup page of the Microsoft Download Center.

For more information about how to plan a Communications Server 2007 and Exchange 2007 Unified Messaging deployment, see Planning an Exchange 2007 Unified Messaging and Office Communications 2007 Server Deployment.

For more information about how to deploy Exchange 2007 Unified Messaging and Communications Server 2007, see Configuring Unified Messaging and Office Communications Server 2007.

The following is a summary of the Unified Messaging features that are available in an integrated Exchange 2007 SP1 and Communications Server 2007 environment:

• Support for additional types of UM dial plans   To interoperate with Communications Server 2007, Exchange 2007 SP1 Unified Messaging supports the following additional types of UM dial plans: SIP URI and E.164. You can configure these UM dial plans by using the Exchange Management Shell and also by using the Exchange Management Console. The Exchange Management Console lets you create SIP URI and E.164-type UM dial plans by using the New Dial Plan wizard. You can also use the Exchange Management Console to supply Session Initiation Protocol (SIP) Uniform Resource Identifiers (URIs) when you enable users and associated them with a SIP URI dial plan.
  For more information about the types of UM dial plans that are available in Exchange 2007 Unified Messaging, see Understanding Unified Messaging Dial Plans.
  
• Additional logic for resolving internal calling numbers   The scope of internal calling number resolution is significantly increased in Exchange 2007 SP1. The original release (RTM) version of Exchange 2007 resolves internal extension numbers against only two sources. These sources are the extension numbers for other UM-enabled users in the same UM dial plan as the user who is calling and the contact list of the user who is being called. In Exchange 2007 SP1, Unified Messaging also resolves internal extension numbers against all users in the Active Directory forest.
  In both Exchange 2007 RTM and Exchange 2007 SP1, when a user is enabled for Unified Messaging, the mailbox is stamped with an Exchange Unified Messaging proxy address (EUM proxy address) that contains their telephone extension number. Unified Messaging tries to resolve the extension number to a user's name by searching the global address list (GAL) and the personal Contacts of the called party for a match. If a match cannot be found, Exchange will use only the telephone extension number in the e-mail message for a missed call. You can enable Unified Messaging to resolve the extension to the user's name by performing one of the following tasks:
  
  • Enable the user for Unified Messaging by using the Enable-UMMailbox cmdlet or the Exchange Management Console. For more information about how to enable a user for Unified Messaging, see How to Enable a User for Unified Messaging.
    
  • Use the Set-Mailbox cmdlet to create a secondary EUM proxy address for the user. For more information about how to create a secondary EUM proxy address for a user, see How to Add, Remove, or Modify Extension Numbers for a UM-Enabled User.
    
  • Add the calling party as a personal contact in Outlook and include the telephone extension number for the contact.
    
  Communications Server 2007 has extended the Active Directory schema to store the numbers for each user in E.164 format. To match incoming fixed-length extensions, whose length is defined by the dial plan, an Exchange Unified Messaging administrator must set the InternationalNumberFormat attribute in the properties of the UM dial plan. The attribute value is prefixed to the incoming extension number. The resulting number is matched against the user's numbers in the Active Directory directory service that are stored in E.164 format.
  For example, a Unified Messaging administrator creates a UM dial plan named Redmond WA, USA. They set the InternationalNumberFormat attribute to “142570xxxxx”. In this example, the number of “x”s is determined by the length of the extension, which is a five digit extension in this example. If the Unified Messaging server answers an incoming call that has the extension 12345, it will combine this extension with the value of the InternationalNumberFormat attribute to obtain the telephone number “tel:+14257012345”. This resulting number is matched against numbers that are stored for all users in the Active Directory forest.
  

  Note:
  InternationalNumberFormat is a single-valued attribute and can be set to only one value. Therefore, only one prefix can be matched, even if an organization uses multiple prefixes (for example, “14257022222” “14257133333”).

• Notification when a caller leaves a voice message and the destination telephone number uses call forwarding   For example, User 1 uses Microsoft Office Communicator 2007 to call Use 2, and User 2 has set up call forwarding to forward calls to User 3. If User 3 does not answer the call, the call is diverted to the Unified Messaging server. The Unified Messaging server answers the call and records a message. The Unified Messaging server sends information back to User 1 that indicates to whom the voice message was routed. This information is rendered by the Office Communicator client. User 1 can see that they are leaving a message for User 3, not for User 2.
  

  Note:
  This feature is available only when you use the Office Communicator 2007 client as the caller’s telephone.

• Support for recording high-fidelity voice messages in Exchange Unified Messaging   Support for high-fidelity sound using the RTAudio codec is added when Exchange 2007 SP1 is used with Communications Server 2007.
  This feature is available when a voice call is initiated by using Office Communicator 2007 and the recipient of the voice call plays the message by using Microsoft Office Outlook 2007 or the 2007 version of Outlook Web Access. The following two scenarios support the high-fidelity recording and playback feature:
  Scenario 1   A Unified Messaging server answers a call on behalf of a subscriber and either of the following is true:
  
  • The subscriber’s audio codec is set to WMA.
    
  • The subscriber's audio codec is not set and the subscriber’s associated UM dial plan audio codec is set to WMA.
    
  Scenario 2   A Unified Messaging subscriber, whose associated UM dial plan audio codec is set to WMA, logs on to Unified Messaging, locates someone in the directory, and leaves them a message.
  For more information about the audio codecs that are used in Unified Messaging, see Understanding Unified Messaging Audio Codecs.
  
• Play on Phone calls cannot be automatically forwarded when they are played on Office Communicator 2007   In Exchange 2007 RTM, the Unified Messaging Play on Phone feature enables users to see whether they have a voice message in Outlook or Outlook Web Access, forward the message to the telephone number they want, and then use that telephone to listen to the message. When Exchange 2007 SP1 is used together with Communications Server 2007, the Play on Phone number can be a Microsoft Office Communicator 2007 endpoint. If you have configured call forwarding to an alternate telephone number, the Play on Phone call will be sent to the Play on Phone number that is configured as an Office Communicator 2007 endpoint and the call will not be forwarded to the alternate telephone number. This feature provides additional voice mail protection because it ensures that a voice message is not forwarded to anyone other than its intended recipient.
  
• Outlook Voice Access can be accessed from Office Communicator 2007 without requiring the user to enter a PIN   If a user is logged on to Office Communicator 2007, they can access Outlook Voice Access directly by pressing the Call voicemail button in Office Communicator 2007. Because the user is already authenticated to the server that is running Communications Server 2007, the user is not prompted to enter their Outlook Voice Access PIN.
  

  Note:
  This functionality is available only when the user is using the Office Communicator 2007 client.

• Office Communicator 2007 clients can associate subjects and priorities to voice messages   When Office Communicator 2007 users make calls, they can associate a subject and priority with the call. When a call has been associated with a priority or a subject, the Unified Messaging server relays the subject and priority of the call in the e-mail messages that it generates for missed call and voice mail notifications. Additionally, if a call is initiated from an e-mail message that the user is reading, Unified Messaging uses the original e-mail subject and priority when generating e-mail messages for missed call and voice mail notifications.
  
• Support for media streams to traverse firewalls   This feature enables Unified Messaging servers to communicate with endpoints outside an enterprise firewall. The A/V Authentication Service authenticates the VoIP media traffic as it flows through the Communications Server 2007 Access Edge server, on which it is co-located. In this situation, the Unified Messaging server is associated with a Communications Server 2007 pool and obtains the appropriate authentication tokens from the Communications Server 2007 Access Edge server that is serving that particular Communications Server 2007 pool.
  When Unified Messaging traffic must traverse an enterprise firewall, the Unified Messaging servers must have the name of the Communications Server 2007 Access Edge server that is assigned to each Office Communications Server pool so that they can obtain the appropriate authentication tokens.
  
• Integration of missed-call-notification e-mail messages with Office Communicator 2007   In deployments that include the Exchange 2007 RTM Unified Messaging and Office Communicator 2005 clients, call notifications are generated independently. For example, if a UM-enabled user who is using Office Communicator misses a call, two missed call notification messages are generated in the user's Inbox: one from Exchange 2007 Unified Messaging and one from Office Communicator 2005. When Exchange 2007 SP1 is integrated with Communications Server 2007, users who are using Office Communicator 2007 receive only one, unique missed call notification in their Inbox.
  

The following features are available in Exchange 2007 SP1 without integrating your Unified Messaging environment with Communications Server 2007:

• Secure Realtime Transport Protocol (SRTP) support   This feature enables SRTP media traffic to flow to and from Exchange Unified Messaging. You can configure SRTP support by using the Exchange Management Shell or the Exchange Management Console. The SRTP configuration settings are located on the UM dial plan object. 
  By default, when you create a UM dial plan, it will communicate in an Unsecured mode and the Unified Messaging servers that are associated with the UM dial plan will send and receive data from IP gateways, IP PBXs, and other Exchange 2007 computers by using no encryption. In Unsecured mode, both the Realtime Transport Protocol (RTP) media channel and SIP signaling information will not be encrypted.
  You can configure a Unified Messaging server to use Mutual Transport Layer Security (MTLS) to encrypt the SIP and RTP traffic that is sent and received from other devices and servers. When you add a Unified Messaging server to a UM dial plan and configure the dial plan to use SIP Secured mode, only the SIP signaling traffic will be encrypted. The RTP media channels will still use Transmission Control Protocol (TCP), which is not encrypted. However, if you add a Unified Messaging server to a UM dial plan and configure the dial plan to use Secured mode, both the SIP signaling traffic and the RTP media channels are encrypted. A secure signaling media channel that uses SRTP also uses MTLS to encrypt the VoIP data.
  For more information about how to help configure VoIP security in Unified Messaging, see Understanding Unified Messaging VoIP Security.
  
• Exchange Management Console support for configuring Transport Layer Security (TLS)   In Exchange 2007 SP1, the Exchange Management Console has been extended to enable you to configure the TLS settings on a UM dial plan. The TLS configuration settings are located on the UM dial plan object. 
  A Unified Messaging server can operate in any mode that is configured on a dial plan because the Unified Messaging server is configured to listen on TCP port 5060 for unsecured requests and TCP port 5061 for secured requests at the same time. A Unified Messaging server can be associated with a single or multiple UM dial plans and can be associated with dial plans that have different VoIP security settings. A single Unified Messaging server can be associated with dial plans that are configured to use a combination of Unsecured, SIP Secured, or Secured mode.
  For more information about VoIP security in Unified Messaging, see Understanding Unified Messaging VoIP Security.
  
• Inband fax tone detection   Fax tone detection enables an IP gateway, an IP PBX, or Exchange Unified Messaging to determine the type of incoming call that is being received. Fax tone detection can work in the following three ways:
  
  • The IP PBX or IP gateway detects the fax tone and sends a reinvite request by using T.38 Session Description Protocol (SDP).
    
  • Fax tone detection can be performed by using both an IP PBX or IP gateway and Unified Messaging. In this method, when the IP gateway or IP PBX detects the fax tone, it does not send a re-invite but instead sends CNG tones (out of band) as named telephony events as defined in RFC 2833. As soon as the IP PBX or IP gateway has sent the CNG tones, the Unified Messaging server performs out-of-band fax tone detection and sends a reinvite by using T.38 SDP.
    
  • If the IP PBX or IP gateway does not use either of these methods, Unified Messaging inband fax tone detection should be turned on. This will enable the Unified Messaging server to detect incoming inband fax tones. By default, this feature is turned off. However, it can be enabled in environments that use IP PBXs or IP gateways that cannot detect fax tones. You enable inband fax tone detection by changing the EnableInbandFaxDetection setting to True in the globcfg.xml file. The globcfg.xml file is located in the \Program Files\Microsoft\Exchange\bin folder on a computer that is running the Unified Messaging server role.
    
  Cisco CallManager 5.x is supported and directly interoperates with Exchange 2007 SP1. However, fax receiving does not work correctly if you are using CallManager 5.x or 6.x even if you have enabled inband fax tone detection. If you do not enable this setting, Unified Messaging servers will rely on IP gateways or IP PBXs to perform fax tone detection. 
  
• Quality of Service (QoS) support by using DiffServ   Quality of Service (QoS) is a set of technologies for managing network traffic in a cost-effective manner. QoS technologies let you measure bandwidth, detect changing network conditions (such as congestion or availability of bandwidth), and prioritize or throttle traffic. Differentiated Services (DiffServ) is a protocol that defines traffic prioritization at Layer 3 of the OSI model. DiffServ classifies and marks the packets as belonging to a specific class and is a simple and scalable mechanism for classifying packets, managing network traffic including voice and video traffic, and ensuring quality of service (QoS) on modern IP networks.
  

  Note:
  Layer 3 network devices, such as routers, must support DiffServ.

  DiffServ operates on the principle of traffic classification, where each network data packet is included in a limited number of traffic classes. However, each router on the network must be configured to differentiate traffic based on its class. Each traffic class can be managed differently, ensuring that higher-priority traffic on the network can be given high priority. DiffServ markings for a packet are included in the IP header.
  RFC 2475 defines the architecture for DiffServ and RFC 2474 defines the bits in the DiffServ field on the network packet. The Type of Service (TOS) field in Internet Protocol version 4 (IPv4) headers and the Traffic Class field in Internet Protocol version 6 (IPv6) headers are used for the DiffServ values. The six most significant bits of the DiffServ field together are called the Differentiated Services Code Point (DSCP). DSCP is a field in an IP packet that enables different levels of service to be assigned to network traffic. This is achieved by marking each packet on the network with a DSCP code and assigning to it the corresponding level of service.
  

  Note:

  If Exchange 2007 SP1 is deployed on a computer that is running the Windows Server 2008 operating system, you can enter IP addresses and IP address ranges in the Internet Protocol Version 4 (IPv4) format, Internet Protocol Version 6 (IPv6) format, or both formats. A default installation of Windows Server 2008 enables support for IPv4 and IPv6. For more information about Exchange 2007 SP1 support for IPv6 addresses, see IPv6 Support in Exchange 2007 SP1.

  In Microsoft Windows Server 2003, TCP/IP performs DiffServ marking when you have installed the Quality of Service (QoS) Packet Scheduler. When you install the Unified Messaging server role on a computer that is running Windows Server 2003 with the QoS Packet Scheduler installed, all outgoing Unified Messaging packets will be marked with the default DSCP value of 40 (101000). However, you can change this default value for the packets by using Registry Editor or by modifying the Group Policy.
  The Exchange 2007 Unified Messaging service does not perform any classification of network packets. However, the media platform that is included with Unified Messaging instructs the Windows networking stack that all audio packets are to be marked as Guaranteed Service. The operating system will then use Group Policy settings to determine how the data packets should be marked and then will mark the TOS field of the IP header. For more information about QoS in Windows, see How QoS Works.
  By default, the QoS Packet Scheduler component is not enabled on Windows Server 2003 and must be installed. The QoS Packet Scheduler can be installed by adding it as a Network Service on the properties of a network connection in Windows Server 2003. However, the QoS Packet Scheduler is installed by default on Windows Server 2008.
  

For more information about all the new features that are found in Exchange 2007 SP1, see What's New in Exchange Server 2007 SP1.