Planning Roadmap for Upgrade and Coexistence

Planning Roadmap for Upgrade and Coexistence - Exchange 2003

Applies to: Exchange Server 2010 Topic Last Modified: 2009-08-19

You can deploy Exchange 2010 in an existing Exchange Server 2003 organization that is operating in native mode. Coexistence with these two Exchange versions is supported. This topic provides an overview of the planning considerations and configuration steps that you must take when Exchange 2010 will coexist with Exchange Server 2003.

Existing Exchange Organization Planning

Requirements	Check
Exchange Server 2003 servers must have a minimum version of Exchange Server 2003 SP2 installed.	[F]
At least one Windows Server 2003 Service Pack 2 (SP2) or later global catalog in each Active Directory site.	[F]
Active Directory must be at least in Windows Server 2003 forest functionality mode.	[F]
Exchange 2010 doesn't support read-only domain controller (RODC)/read-only global catalog (ROGC) servers.	[F]
Ensure that your organization meets the Exchange 2010 System Requirements.	[F]
Ensure that your organization meets the Exchange 2010 Prerequisites.	[F]

Understanding Coexistence

Any organization that is upgrading from Exchange Server 2003 or Exchange 2010 will experience a period of coexistence. A large organization that has many routing groups must plan their routing topology to maintain mail flow during the coexistence period.

Successful coexistence of Exchange 2010 with Exchange Server 2003 depends on correct configuration of routing group connectors between Exchange14 Hub Transport servers and Exchange Server 2003 bridgehead servers. When you install Exchange14 in a forest with an existing Exchange organization, you select to join Exchange 2010 to that organization. During installation, you are also prompted to specify an Exchange 2003 bridgehead server in the routing group to which you want to create the initial routing group connector. Because of differences in how server-to-server communication occurs, you must configure routing group connectors to let the two Exchange versions communicate and exchange messages. For more information about how to plan a routing topology for Exchange 2010 and Exchange 2003, see Coexisting with Exchange 2003 Transport.
(E2K3 – SMTP, E14 - RPC)
Exchange Server 2003 used Simple Mail Transfer Protocol (SMTP) as the primary communication protocol between Exchange servers. In Exchange 2010, the server roles use RPC for server-to-server communication and rely on the Hub Transport server to perform SMTP transport. For more information about how server-to-server communication occurs in Exchange 2007, see Understanding Transport Pipeline.

The Exchange 2010 server role features that are available to clients in the Exchange organization during the coexistence period depend on the version of the Exchange server where the user's mailbox is stored and the version of the e-mail client application that is used to access Exchange.

Choosing the order of Active Directory sites for upgrade

When you are ready to begin upgradeing your organization to Exchange 2010, you must start with the internet accessible Active Directory sites first, and then upgrade your internal Active Directory sites.

Choosing the order of server roles for upgrade

Within the first Active Directory site or sites you are upgradeing, the first Exchange 2010 server role you will install will be the Client Access server role. Depending on the size of your Active Directory site, this might be a single Client Access server computer or a load balanced array of Exchange 2010 Client Access servers. After you install the first Client Access server, the recommended order to install the E14 server roles is the following:

Hub Transport Server role
Unified Messaging (UM) Server role
Mailbox Server role

Note:

When upgradeing to Exchange 2010, you can't perform an in-place server upgrade on an existing Exchange server role.

Topologies

Exchange 2010 supports the following topologies:

Single forest, multiple Active Directory sites.
Multiple forests (resource forest model), multiple Active Directory sites.
Single Active Directory site.

Exchange 2010 doesn't support the following topologies:

Coexistence with Exchange 2000 server or earlier.
Coexistence with Exchange 2003 versions prior to Service Pack 2 (SP2).
Installing older version of Exchange into a newly created Exchange 2010 organization.

Administration Differences

Exchange Server 2003 uses Administrative Groups to organize Exchange objects for the purposes of delegating permission to manage those objects. Exchange 2010 does not use Administrative Groups as a logical management unit for administrative delegation. However, to support coexistence between Exchange Server 2003 and Exchange 2010, all Exchange 2010 servers are automatically put in a single Administrative Group when Exchange 2010 is installed. This Administrative Group is recognized in the Exchange System Manager of earlier versions of Exchange as Exchange Administrative Group (FYDIBOHF23SPDLT).

Caution:

Do not move Exchange 2010 servers out of Exchange Administrative Group (FYDIBOHF23SPDLT) and do not rename Exchange Administrative Group (FYDIBOHF23SPDLT) by using a low-level directory editor. Exchange 2010 must use this administrative group for configuration data storage. We do not support moving Exchange 2010 servers out of Exchange Administrative Group (FYDIBOHF23SPDLT) or renaming of Exchange Administrative Group (FYDIBOHF23SPDLT).

You must use the Exchange Server 2003 System Manager and utilities to manage the Exchange Server 2003 servers. In Exchange 2010, you must manage Exchange 2010 servers and mailboxes by using the Exchange Management Console or the Exchange Management Shell. However, you can use the Exchange Management Console to view some attributes on Exchange Server 2003 servers. For more information on Exchange management console interoperability, see Exchange Management Console Interoperability.

Routing Differences (下一篇會在談)

When you plan for a period of coexistence with Exchange 2010 and Exchange Server 2003, you must understand the differences in how each version determines its routing topology.

For more information about routing and coexistence, see Upgrading from Exchange 2003 Transport.

Hub Transport Server Coexistence

The Hub Transport server role is designed to handle all mail flow for the Exchange organization. It is also responsible for handling Transport Rules, Journaling policies and message delivery. This server is deployed in the Active Directory forest and is required for Exchange 2010 mailboxes to send and receive messages. Messages that are sent to the Internet are relayed by the Hub Transport server to the Edge Transport server or a third-party smart host.

You can add an Exchange 2010 Hub Transport server to an existing Exchange organization after you successfully deploy Exchange 2010 CAS servers. When you introduce Exchange 2010 Hub servers in your Exchange 2003 environment, all Exchange 2010 Hub servers are placed in a single separate routing group. To enable mail flow between the Exchange 2010 deployment and your existing Exchange 2003 organization, you need to create a Routing Group connector. This Routing Group connector is created during the setup of your first Exchange 2010 Hub Transport server.

To learn more about introducing Exchange 2010 Hub Transport servers to your Exchange 2003 organization, see Upgrading from Exchange 2003 Transport.

Edge Transport Server Coexistence (跳過)

The Edge Transport server role is designed to provide improved antivirus and anti-spam protection for the Exchange organization. The Edge Transport server also applies policies to messages in transport between organizations. This server role is deployed in the perimeter network and outside the Active Directory forest. The Edge Transport server can be deployed as a smart host and SMTP-relay server for an existing Exchange Server 2003 organization.

You can add an Edge Transport server to an existing Exchange organization without upgrading the internal Exchange servers or making any organizational changes. You do not have to perform any Active Directory preparation steps when you install the Edge Transport server. If you are using the Exchange Intelligent Message Filter in Exchange Server 2003 to perform anti-spam tasks, you can use the Edge Transport server to provide an additional layer of anti-spam protection. The Edge Transport server provides antivirus and anti-spam protection as messages enter the network.

When an Edge Transport server is deployed to support an Exchange organization that has not yet deployed Exchange 2010, a limited set of features are available. You can't create an Edge Subscription in this scenario. Therefore, you can't use the Recipient Lookup or safelist aggregation features. For more information on Edge Transport servers and coexistence, see Upgrading from Exchange 2003 Transport.

Mailbox Server Coexistence

The Mailbox server role can coexist with Exchange Server 2003 mailbox servers. For Exchange 2010 and Exchange Server 2003 mailbox servers to coexist, you must be able to send mail among the mailboxes. Exchange 2010 uses the Hub Transport server to send mail. An Exchange 2010 Hub Transport server must be deployed in each Active Directory site that contains an Exchange 2010 Mailbox server.

If you move a mailbox from Exchange Server 2003 to Exchange 2010, and the mailbox is part of an e-mail address policy, the e-mail addresses for that mailbox is automatically updated based on the configuration of the e-mail address policy. If the mailbox had a primary SMTP address that differs from the e-mail address that is enforced by the e-mail address policy, that SMTP address becomes a secondary SMTP address and the e-mail address generated by the e-mail address policy becomes the primary SMTP address. For information about how to move mailboxes, see Managing Move Requests. (目前有部份VIP的Primary address 是手動改的，與recipient policy 不符，這部份遷移後要在手動改回來)

You can replicate public folder data between Exchange 2010 and Exchange Server 2003 public folder databases. To do this, you must create a replica of the public folder using the Exchange Server 2003 System Manager.(公用資料夾移轉從Exchange 2003 進行，信箱則是要從E14介面遷移) For more information on Exchange 2010 and Exchange Server 2003 public folder coexistence, see ANDREA FOWLERS TOPIC.

Client Access Server Coexistence

The Client Access server role provides the functionality that was provided by a front-end server in Exchange 2003 and more. All client connectivity (including Outlook MAPI connectivity) now goes through the Client Access server role. (CAS 的用戶端存取需求會很大，且要對外，跟mailbox role 溝通頻繁， 要放DMZ(微軟不建議) or server farm(不直接開port 的話，則必須透過ISA publish)) There are no longer any clients directly connecting to the mailbox server role. The Client Access server role can coexist with Exchange Server 2003 servers. The following list describes the Exchange 2010 dependencies and requirements for coexistence with Exchange Server 2003.

Whether a user sees the Outlook Web Access client of Exchange Server 2003 or Exchange 2010 depends on the location of the user's mailbox. For example, if the user's mailbox is located on an Exchange Server 2003 back-end server and the Client Access server is running Exchange 2010, the user will see the Exchange Server 2003 version of Outlook Web Access. (E14 CAS 是支援存取 E2K3 B-E)
The version of Exchange ActiveSync that clients use also depends on the server version that is hosting the user's mailbox. The user's mailbox must be located on a server that is running Exchange Server 2003 Service Pack 2 or Exchange 2010 to have Direct Push enabled for Exchange ActiveSync.
When you perform a upgrade from Exchange Server 2003 to Exchange 2010, you will typically upgrade all the Exchange servers in a particular routing group or Active Directory site to Exchange 2010 at the same time, configure coexistence, and then upgrade the next site.

Important:

When upgradeing an Exchange 2003 organization, an Exchange 2003 Front End server is required in order to support the upgrade. For each Exchange 2010 Client Access server, you can only configure one Outlook Web Access 2003 URL for redirection. You can accomplish this with a single Exchange 2003 Front End server or a load balanced array of Exchange 2003 Front End servers.

Exchange 2007 introduced the Autodiscover and Availability services. The Autodiscover service configures client computers that are running Outlook 2007, Outlook 2010, Entourage, and other client applications. The Autodiscover service can also configure supported mobile devices.(從E2K7 開始，就不用外部設定的SOP，user只要知道自己的email address，在裝個憑證，可以上網，不管outlook ROH or mobile device 通通會自動設定好) The Autodiscover service provides access to Microsoft Exchange features for Outlook 2007 and later clients that are connected to your Microsoft Exchange messaging environment. The Availability service improves information workers' calendaring and meeting scheduling experience by providing secure, consistent, and up-to-date free and busy information to computers running Outlook 2007 and later. For more information on the Autodiscover service, see (http://technet.microsoft.com/en-us/library/bb124251.aspx). For more information on the Availability service, see (http://technet.microsoft.com/en-us/library/bb232134.aspx). For more information on Client Access server coexistence between Exchange Server 2003 and Exchange 2010, and new Exchange 2010 features, see Upgrading from Exchange 2003 Client Access.

Unified Messaging Server Interoperability

The Unified Messaging server role is designed to provide Unified Messaging (UM) for Exchange 2010 recipients. UM combines voice messaging, and e-mail messaging into one store that can be accessed from a telephone, a user's computer, and a mobile device. Users can access voice messages, e-mail, and calendar information that are located in their Exchange 2010 mailbox from e-mail clients, such as Outlook and Outlook Web Access.

The Unified Messaging server depends on the Hub Transport server and Mailbox server. All SMTP mail submitted from a Unified Messaging server must be submitted to an Exchange 2010 Hub Transport server. For a recipient to use Unified Messaging, they must have an Exchange 2010 mailbox.

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Planning Roadmap for Upgrade and Coexistence - Exchange 2003

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