Executive Summary:
The release of Microsoft Exchange Server 2007 Service Pack 1 (SP1) introduces new functionality and improvements that will interest Exchange Server administrators and messaging system architects. Exchange 2007 SP1 introduces a new feature called standby continuous replication (SCR) that can replicate mailbox databases to geographically remote locations. This Exchange Server update is also supported on Windows Server 2008, and includes improvements to unified messaging (UM), Outlook Web Access (OWA), message transport, public folder management, and many other features.

Microsoft Exchange Server 2007 SP1 introduces a wealth of new functionality that will interest messaging system architects and administrators. Microsoft has previously differentiated between service pack releases, intended to address bugs and other minor flaws, and feature pack releases, which add significant new functionality to the base product. That definition certainly indicates that Exchange 2007 SP1 is as much a feature pack release as a service pack. Let’s take a look at the enhancements coming in SP1 and see what they might mean for your organization.

Standby Continuous Replication
Chief among the new features in SP1 is standby continuous replication (SCR). Microsoft introduced local continuous replication (LCR) and cluster continuous replication (CCR) with Exchange 2007. LCR, as its name suggests, replicates database transactions to another local disk on the same Exchange 2007 server. LCR is useful if you lose a database or the drive that hosts a database because another copy is available that’s been kept up to date by using LCR’s log shipping and replay technology, but LCR is limited because it replicates data only within the same Exchange server. In contrast, CCR provides replication of database transaction data between two nodes in a cluster. This technology is focused on high-availability and failover scenarios and obviously requires the use of Exchange clusters.

Enter SCR. This solution arguably falls somewhere between the functionality of LCR and CCR. LCR focuses more on the notion of data copying than data protection and high availability. With SCR, you can replicate database log files to another Exchange 2007 server anywhere in your Exchange organization, provided it’s in the same Active Directory (AD) domain, though it need not be in the same AD site. Therefore, SCR lets you replicate mailbox databases to locations that might be geographically remote from your source Exchange server.

SCR gives you more flexibility than LCR because the replication is off-node and more flexibility than CCR because you aren’t limited to a single Exchange cluster to host the source and target nodes of the replication. If you lose the source server with SCR, you still have a copy of the data elsewhere on your network; you can either rebuild the server and copy the data back or use the replicated mailbox data on another server and rehome affected users. You can also combine SCR with LCR or CCR technologies. A source server can have LCR enabled as well as SCR to a remote location; similarly, a source server can be a cluster member either with or without CCR enabled.

Unlike LCR and CCR, SCR lets you replicate data for a given storage group to multiple locations. So, for that really important database, you can have replicated copies of the transaction logs in several locations. Similarly, an SCR target can have multiple sources—you can designate a single Exchange server in a remote location to be the SCR target for many different source servers. Just like LCR and CCR, you can use SCR only on storage groups that contain a single database, but you can have multiple storage groups replicated using SCR. SCR requires that both the source and target servers are running SP1 and also that an SCR target can’t be running LCR. SCR doesn’t provide any automated way of failing over databases if a problem occurs on the source server. You’ll have to construct the operational procedures appropriate to how you deploy SCR within your organization.

CCR Improvements
In Exchange 2007 RTM, all transaction log copying for CCR takes place over the public network in the cluster, which can cause communication problems. For example, when the passive node comes back online after being unavailable, you can get bottlenecking due to CCR replication contending with normal client traffic. Also, if the public network fails, a failover can take place without all transaction log data being replicated, despite the data being available.

With SP1, administrators can create mixed networks to take care of log shipping. For example, you can use the internal cluster network (which usually carries just the cluster heartbeat traffic) to ship logs between servers and so avoid contention with client traffic. SP1 also brings general performance improvements for clusters, including reduction in I/O for CCR and improved clustered Mailbox server transition when using CCR.

Exchange 2007 Meets Windows Server 2008
Although Exchange 2007 RTM isn’t supported on Windows Server 2008 (previously codenamed Longhorn), SP1 is designed specifically to work with Server 2008. SP1 exploits Server 2008’s improved clustering support, enhancing Exchange 2007’s overall clustering capability.

Without SP1, Exchange 2007 clusters are supported only on Windows Server 2003 and can’t span multiple IP subnets. Add SP1 and Server 2008, and the IP subnet limitation is removed—Exchange clusters can now be geographically dispersed across separate IP subnets. This capability simplifies the creation and management of infrastructures for wide-area Exchange clustering: virtual LAN technology between remote data centers, for example, is no longer required.

This new functionality brings with it new challenges. If a Mailbox server in a wide-area cluster fails over to a node in a different IP subnet, the IP address of the Mailbox server will change even though the DNS name of the server stays the same. SP1 uses routable protocols for clusters, as opposed to the broadcaststyle protocols of pre-SP1 clusters. Therefore, clients must be able to connect to the remote failover node using DNS because the failover process dynamically updates the DNS entry for the clustered Mailbox host. For this reason, Microsoft recommends using a short Time to Live (TTL) value for clustered Mailbox DNS records. Administrators also need to pay attention to the local DNS cache on client computers; to ensure that DNS resolution takes place using valid data after a failover, you can run the Ipconfig command with the /flushdns switch on client computers. You might be able to implement this procedure with a logon script, or perhaps a desktop icon to execute the command would be appropriate.

Implementing SP1 on Server 2008 also provides messaging architects and administrators an opportunity to brush up on their IPv6 skills: IPv6 native networks are supported with Exchange 2007 SP1. However, this is a tricky area because DHCP IPv6 isn’t supported on Server 2008; only static addresses are supported. SP1 includes several new setup options for /NewCMS and /RecoverCMS relating to clustered Mailbox server configurations in both IPv4 and IPv6 environments.

OWA Gets Back What It Lost—and More
Outlook Web Access (OWA) for Exchange 2007 was completely rewritten from the version for Exchange 2003. Unfortunately, not all of the OWA 2003 features were ported to OWA 2007, due largely to time constraints. Some of these previous OWA features are returned in SP1 and some new features have been added as well.

OWA Light has been enhanced with activity monitoring so that the session isn’t timed out if, for example, it takes a long time to enter a message. Also, when messages are being composed, they’re automatically saved in the Drafts folder if the session times out because of inactivity. This is a welcome improvement for avid OWA Light users. The experience for OWA Premium users is improved as well. Users can now create and edit Personal Distribution Lists, create and edit server-side rules, and access the Recover Deleted Items feature. Users will be happy to see that access to Public Folders from the OWA Premium client is back. OWA Premium’s WebReady Document Viewing now supports Office 2007 so that these files can be viewed in HTML format. OWA Premium also adds a monthly calendar view (previously it had only daily and weekly views) and support for Secure MIME (S/MIME) for receiving and sending of signed or encrypted email.

Exchange Transport Improvements
SP1 has a range of different transport improvements that cut across core transport functionality as well as specific improvements for the Edge Transport and Hub Transport server roles. Core transport functionality has been improved specifically in the back pressure feature. This feature helps you monitor key resources such as free space on drives that hold message queue databases and transaction logs, the number of uncommitted message queue database transactions in memory, and memory utilization by EdgeTransport.exe and other system processes. With back pressure, if system resources become too heavily utilized, Exchange stops accepting new messages to prevent the server’s resources from becoming completely exhausted. The net result is that the overall stability and reliability of the Exchange system is improved. The disk space requirements for back pressure have been refined from 4GB in Exchange 2007 RTM down to 500MB in SP1. SP1 also adds additional options for configuring other transport feature settings.

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SP1 optimizes the basics of message processing for the Hub Transport role. Some of the specific enhancements include:

  • priority queuing so that the categorizer takes into account user-set priorities on messages
  • adding a MaxMessageSize parameter to the Set-AdSiteLink cmdlet so that an administrator can set a maximum message size for messages relayed between AD sites
  • adding a MaxMessageSize parameter to the New-RoutingGroupConnector and Set- RoutingGroupConnector cmdlets for controlling maximum sizes of legacy Routing Group Connectors
  • controlling the scope of Send connectors to AD sites
  • enabling transport rules to act on unified messaging (UM) messages
  • enhancements for Windows Rights Management Services (RMS)
  • X.400 support

To improve Edge Transport server management, SP1 adds a Server parameter to the Start- EdgeSynchronization cmdlet so that administrators can run the cmdlet from a remote computer. The Test-EdgeSynchronization cmdlet has been enhanced so that results on subscription status for individual users can be verified. The cloned configuration scripts have been improved so that cloning of configuration information, server deployment, and backup and restore are optimized for environments that use multiple Edge Transport servers.

UM Server Role Enhancements
To increase interoperability with Office Communications Server (OCS) 2007, SP1 enhances the UM server role significantly. Some of the new features you’ll get when using SP1 and OCS 2007 together include:

  • a New Dial Plan wizard to create E.164 and Session Initiation Protocol (SIP) Uniform Resource Identifier (URI) dial plans
  • new logic for resolving calling numbers
  • forwarding notification when leaving voice messages
  • high-fidelity voice message recording
  • PIN-less access to Outlook Voice Access from Office Communicator
  • subject and priority association in Communicator
  • media stream firewall traversal
  • missed call notification integration in Communicator
  • prohibiting play on calls with Communicator that are subject to call forwarding rules
  • the ability to properly handle incoming fax calls from OCS

Even without OCS 2007, SP1 offers UM improvements such as support for Secure Real-time Transport Protocol (SRTP), configuration of Mutual Transport Layer Security for dial plans through Exchange Management Console, the Enable UM wizard for adding SIP or E.164 addresses for users, modification of extension numbers and SIP or E.164 addresses for UM users through Exchange Management Console, fax tone detection, and Quality of Service support.

A Host of Additional Features
SP1 has many other improvements in addition to the major enhancements I’ve described. Although perhaps not as dramatic, these features will undoubtedly be warmly received by Exchange administrators.

Move Mailbox. Move Mailbox has been a favorite feature of Exchange administrators for years. Exchange 2007 greatly improved Move Mailbox by adding Exchange Management Shell scripting capabilities, and SP1 brings yet more improvements.

With SP1, an administrator can export mailbox content to a PST file by using the PSTFolderPath parameter with the Export- Mailbox cmdlet. You can combine this operation with other parameters to filter content or export multiple mailboxes. Clearly, this functionality is useful for data migration operations that would otherwise be limited by bandwidth restrictions, or in support of e-discovery requests for litigation.

Exchange ActiveSync. EAS has received improvements geared for both administrators and end users. When the Client Access server role is configured on a server with SP1, a default EAS policy is created. Any users without an EAS policy will have this new default policy applied. This change means administrators no longer have to explicitly apply a default policy to new EAS users. Administration requires less effort and you’ll have better security for your environment.

New EAS policy settings are also available. With these new policies, administrators can enforce encryption of main memory contents on the remote device; disable removable storage capability; disable POP3, IMAP4, Short Message Service (SMS), and Message Management System (MMS) capability; block applications; or disable Wi-Fi, Bluetooth, or infrared capabilities on mobile devices. This kind of device control greatly enhances security. However, note that some of these features aren’t supported on Windows Mobile 6.0, and some require the Exchange 2007 Enterprise CAL. To use the full suite of features enabled by EAS in SP1, the bottom line is that you’ll need to invest in new devices that aren’t available yet and won’t be until Microsoft and OEMs introduce devices that run Windows Mobile 6.1.

In addition, the remote wipe capability now offers a confirmation option before a mobile device is reinitialized, and Direct Push functionality has been improved by reducing the amount of data that is sent and received by the device.

POP3 and IMAP4. Exchange Management Console has been enhanced to provide a new administrative interface for POP3 and IMAP management; previously, these functions were available only through Exchange Management Shell. You’ll find the interface by navigating to Client Access under Server Configuration in the console tree, clicking either the POP3 or IMAP4 tab, then selecting Properties. Exchange Web Services. With the big developer push toward Web services in Exchange, it’s encouraging to see that Exchange Web Services now includes access to and manipulation of Public Folders, management of delegates and access to delegate resources, permissions management, and identifier translation.

Public folders. Despite public folders being de-emphasized in Exchange 2007, many organizations continue to use them. SP1 has brought some necessary management improvements. Administrators will welcome the Public Folder Management Console as a means to create and manage public folders via Exchange Management Console. You can also manage public folder referrals via the Properties tab of a pubic folder database in Exchange Management Console. In Exchange 2007 RTM, you have to use Exchange Management Shell to perform these actions, but SP1 gives you a choice. Another boon to administrators is the addition of a new administrator role called Exchange Public Folder Administrator that you can use to granularly delegate Public Folder management.

For end users, mail-enabled public folders now appear when previewing membership of address lists, address policies, and Distribution Groups—including dynamic ones.

Mailbox management. SP1 introduces bulk mailbox creation through Exchange Management Console when you select multiple existing user accounts. You also get two new wizards: the Manage Full Access Permission wizard, which lets you grant or remove Full Access permission for a mailbox; and the Manage Send As Permissions wizard, which lets you grant or remove Send As permissions.

Messaging records management. To establish some level of parity with the Mailbox Manager feature of Exchange 2000 Server and Exchange Server 2003, SP1 lets you apply messaging records management (MRM) policies to managed default folders (e.g., Inbox) even with the Standard version of Exchange. For managed custom folders, each mailbox that uses MRM must have an Exchange Server Enterprise CAL.

Defragmentation monitoring. A minor but perhaps useful addition for administrators is the extended information for Event 703, which can help you monitor online defragmentation pass completions. With Exchange 2007 RTM, such monitoring is a cumbersome process that requires analyzing the event log and matching Event 700 and Event 703 messages to determine how successful online defragmentation attempts have been over time. With SP1, all the information you need—and more—is contained in Event 703. Figure 1 shows an example of the enhanced text.

Performance Monitor has received two new Extensible Storage Engine (ESE) performance counters that also monitor the effectiveness and efficiency of online defragmentation: Instances\Online Defrag Pages Freed/Sec shows the number of pages freed per second as a result of online defragmentation, and Instances\Online Defrag Data Moves/Sec shows the number of times per second that data is moved from one page to another during online defragmentation.

Transport dumpster. SP1 uses an enhanced transport dumpster process to support lossy recoveries in an LCR environment. In Exchange 2007 RTM, the transport dumpster is automatically exploited during a CCR recovery; the Restore-StorageGroupCopy cmdlet has been updated in SP1 to include a call to the transport dumpster in LCR recovery to provide messages that might have been lost as a result of the failure of the storage group in question.

Exchange Management Console. SP1 offers a new Manage Clustered Mailbox Server wizard that provides the same functionality as the Move-, Stop-, and Start-ClusteredMailboxServer cmdlets. And there are new controls in Exchange Management Console that have the same functionality as the Suspend-, Resume-, Update-, and Restore-StorageGroupCopy cmdlets.

Dramatic Advances with SP1
SP1 brings a wealth of new features and enhancements for Exchange messaging architects, administrators, and end users. Some are just nice-to-have improvements, but others, such as SCR, can have a much more dramatic effect on the design and deployment of your messaging environment. To get the best out of these new improvements, you should spend some time investigating what all of these new changes can do for your environment.