Exchange 架構Exchange architecture

Exchange 使用單一建置組塊架構,為各種規模的部署提供電子郵件服務,小至小型組織大至跨國 (地區) 企業。下圖描述這種架構。Exchange use a single building block architecture that provides email services for deployments at all sizes, from small organizations to the largest multi-national corporations. This architecture is describe in the following diagram.

Exchange 架構

下列各節描述個別元件。Individual components are described in the following sections.

伺服器通訊架構Server communication architecture

Exchange 伺服器與新舊版 Exchange 之間的通訊是在通訊協定層級進行。不允許跨層級通訊。此通訊架構就是「每部伺服器就是一座小島」。這個架構具有下列好處:Communication between Exchange servers and past and future versions of Exchange occurs at the protocol layer. Cross-layer communication isn't allowed. This communication architecture is summarized as "every server is an island". This architecture has the following benefits:

  • 減少伺服器間的通訊。Reduced inter-server communications.

  • 版本感知通訊。Version-aware communications.

  • 隔離失敗。Isolated failures.

  • 每部伺服器內的整合式設計。Integrated design inside each server.

下圖顯示 Exchange 伺服器之間的通訊協定層級通訊。Protocol layer communication between Exchange servers is shown in the following diagram.

Exchange 伺服器之間的通訊

伺服器角色架構Server role architecture

Exchange 使用信箱伺服器和 Edge Transport Server。下列各節描述這些伺服器角色。Exchange uses Mailbox servers and Edge Transport servers. These server roles are described in the following sections.

信箱伺服器Mailbox servers

  • 信箱伺服器包含用來路由傳送郵件的傳輸服務。如需詳細資訊,請參閱郵件流程和傳輸管線Mailbox servers contain the transport services that are used to route mail. For more information, see Mail flow and the transport pipeline

  • 信箱伺服器包含處理、轉譯和儲存資料的信箱資料庫。如需詳細資訊,請參閱管理 Exchange 中的信箱資料庫Mailbox servers contain mailbox databases that process, render, and store data. For more information, see Manage mailbox databases in Exchange Server.

  • 信箱伺服器包含接受所有通訊協定之用戶端連線的用戶端存取服務。這些前端服務負責信箱伺服器上對應後端服務的路由傳送或「Proxy 處理」** 連線。用戶端不直接連接後端服務。如需詳細資訊,請參閱本文章稍後的用戶端存取通訊協定架構一節。Mailbox servers contain the Client Access services that accept client connections for all protocols. These frontend services are responsible for routing or proxying connections to the corresponding backend services on a Mailbox server. Clients don't connect directly to the backend services. For more information, see the Client Access protocol architecture section later in this topic.

  • 在 Exchange 2016 中,信箱伺服器包含整合通訊 (UM) 服務,可提供信箱的語音信箱和其他電話語音功能。In Exchange 2016, Mailbox servers contain the Unified Messaging (UM) services that provide voice mail and other telephony features to mailboxes.

    注意

    Exchange 2019 中沒有整合通訊。Unified Messaging is not available in Exchange 2019.

  • 您可以使用 Exchange 系統管理中心 (EAC) 和 Exchange 管理命令介面 來管理信箱伺服器。如需詳細資訊,請參閱 Exchange Server 中的 Exchange 系統管理中心Exchange Server PowerShell (Exchange 管理命令介面)You manage Mailbox servers by using the Exchange admin center (EAC) and the Exchange Management Shell. For more information, see Exchange admin center in Exchange Server and Exchange Server PowerShell (Exchange Management Shell).

Edge Transport ServerEdge Transport servers

  • Edge Transport Server 處理 Exchange 組織的所有外部郵件流程。Edge Transport servers handle all external mail flow for the Exchange organization.

  • Edge Transport Server 一般安裝在周邊網路中,並供內部 Exchange 組織訂閱。EdgeSync 同步處理程序可在郵件進入和離開 Exchange 組織時,讓 Edge Transport Server 使用收件者和其他設定資訊。Edge Transport servers are typically installed in the perimeter network, and are subscribed to the internal Exchange organization. The EdgeSync synchronization process makes recipient and other configuration information available to the Edge Transport server as mail enters and leaves the Exchange organization.

  • Edge Transport Server 可在郵件進入和離開您的 Exchange 組織時提供反垃圾郵件及郵件流程規則。如需詳細資訊,請參閱 在 Exchange Server 防垃圾郵件保護Edge Transport servers provide antispam and mail flow rules as mail enters and leaves your Exchange organization. For more information, see Antispam protection in Exchange Server

  • 您可以使用 Exchange 管理命令介面來管理 Edge Transport Server。如需詳細資訊,請參閱 Exchange Server PowerShell (Exchange 管理命令介面)You manage Edge Transport servers by using the Exchange Management Shell. For more information, see Exchange Server PowerShell (Exchange Management Shell).

如需 Edge Transport Server 的詳細資訊,請參閱<Edge Transport Server>。For more information about Edge Transport servers, see Edge Transport servers.

高可用性架構High availability architecture

下列各節描述 Exchange Server 中的高可用性功能。The high availability features in Exchange Server are described in the following sections.

信箱高可用性Mailbox high availability

資料庫可用性群組 (DAG) 是 Exchange Server 內建高可用性和站台恢復架構的基礎元素。DAG 是一組可主控資料庫集的信箱伺服器群組,並提供從資料庫、網路和伺服器的失敗中自動進行資料庫層級復原的功能。而且,與 Exchange 2013 相較之下,Exchange 2016 中的 DAG 已經過改良。如需 DAG 的詳細資訊,請參閱資料庫可用性群組A database availability group (DAG) is the fundamental element of the high availability and site resilience framework that's built into Exchange Server. A DAG is a group of Mailbox servers that host a set of databases and provides automatic, database-level recovery from database, network, and server failures. And DAGs in Exchange 2016 or later have been improved compared to Exchange 2013. For more information about DAGs, see Database availability groups.

傳輸高可用性Transport high availability

  • Transport Service 會進行所有傳輸中郵件的備援複本。這項功能稱為「陰影備援」**。The Transport service makes redundant copies of all messages in transit. This feature is known as shadow redundancy.

  • Transport Service 會進行所有已傳遞訊息的備援複本。此項功能稱為「安全網路」**。The transport service makes redundant copies of all delivered messages. This feature is known as Safety Net.

  • 在 Exchange Server 中,DAG 代表傳輸高可用性邊界。讓 DAG 跨多個 Active Directory 站台,即可達到站台恢復。In Exchange Server, a DAG represents a transport high availability boundary. You can achieve site resilience by spanning a DAG across multiple Active Directory sites.

  • 在 Exchange Server 中,傳輸高可用性不只是訊息備援的最佳使用,因為備援不是取決於傳送端郵件伺服器所支援的功能。因此,您可以假設 Exchange Server 嘗試在傳遞期間及之後保留訊息的多個複本來保證訊息備援。In Exchange Server, transport high availability is more than a best effort for message redundancy, because redundancy doesn't depend on supported features of the sending mail server. Therefore, you can say that Exchange Server attempts to guarantee message redundancy by keeping multiple copies of messages during and after delivery.

如需詳細資訊,請參閱<傳輸高可用性>。For more information, see Transport high availability.

用戶端存取通訊協定架構Client Access protocol architecture

Exchange 信箱伺服器上的用戶端存取服務負責接受所有形式的用戶端連線。用戶端存取 (前端) 服務會對目的地信箱伺服器 (保留使用者信箱作用中複本的本機伺服器或遠端信箱伺服器) 上後端服務的這些連線進行 Proxy 處理。用戶端不直接連接後端服務。下圖顯示這類通訊。The Client Access services on Exchange Mailbox servers are responsible for accepting all forms of client connections. The Client Access (frontend) services proxy these connections to the backend services on the destination Mailbox server (the local server or a remote Mailbox server that holds the active copy of the user's mailbox). Clients don't directly connect to the backend services. This communication is shown in the following diagram.

用戶端與 Exchange 伺服器的通訊方式

用戶端所使用的通訊協定決定用來對目的地 Mailbox Server 上後端服務之要求進行 Proxy 處理的通訊協定。例如,如果用戶端使用 HTTP 進行連接,則 Mailbox Server 使用 HTTP 對目的地 Mailbox Server 的要求進行 Proxy 處理 (使用自我簽署憑證透過 SSL 進行保護)。如果用戶端已使用 IMAP 或 POP,則使用的通訊協定是 IMAP 或 POP。The protocol that's used by a client determines the protocol that's used to proxy the request to the backend services on the destination Mailbox server. For example, if the client connected using HTTP, the Mailbox server uses HTTP to proxy the request to the destination Mailbox server (secured via SSL using a self-signed certificate). If the client used IMAP or POP, then the protocol that's used is IMAP or POP.

在 Exchange 2016 中,電話語音要求與其他用戶端連線不同。信箱伺服器會將要求「重新導向」** 至保留使用者信箱作用中複本的信箱伺服器,而不是對要求進行 Proxy 處理。需要有電話語音裝置,才能直接建立其與目的地 Exchange 2016 信箱伺服器上整合通訊服務的 SIP 和 RTP 工作階段。In Exchange 2016, telephony requests are different than other client connections. Instead of proxying the request, the Mailbox server redirects the request to the Mailbox server that holds the active copy of the user's mailbox. Telephony devices are required to establish their SIP and RTP sessions directly with the Unified Messaging services on the destination Exchange 2016 Mailbox server.

注意

Exchange 2019 中沒有整合通訊。Unified Messaging is not available in Exchange 2019.

Exchange 架構變更Exchange architecture changes

  • 伺服器角色合併:在 Exchange 2013 或更早的版本中,您可以在不同的電腦上安裝 Client Access server role 和 Mailbox server role。在 Exchange 2016 或更新版本中,Client Access server role 會自動安裝為 Mailbox server role 的一部分,而 Client Access server role 無法作為個別安裝選項。這項變更反映 Exchange 伺服器角色共置的原理,而共置是 Exchange 2010 之後的建議最佳做法。多角色 Exchange 伺服器架構為您提供下列優點:Server role consolidation: In Exchange 2013 or earlier, you could install the Client Access server role and the Mailbox server role on separate computers. In Exchange 2016 or later, the Client Access server role is automatically installed as part of the Mailbox server role, and the Client Access server role isn't available as a separate installation option. This change reflects the philosophy of Exchange server role co-location that's been a recommended best practice since Exchange 2010. A multi-role Exchange server architecture gives you the following tangible benefits:

    • 您環境中的所有 Exchange 伺服器 (任何 Edge Transport Server 可能是例外) 可以完全相同:相同硬體、相同設定等。這種統一性可簡化硬體採購,也可簡化 Exchange 伺服器的維護與管理作業。All Exchange servers in your environment (with the likely exception of any Edge Transport servers) can be exactly the same: the same hardware, the same configuration, etc. This uniformity simplifies hardware purchasing, and also maintenance and management of the Exchange servers.

    • 您可能需要較少的實體 Exchange 伺服器。這會導致較少的持續維護成本、較少的 Exchange 伺服器授權,以及減少的機架、地板空間和電源需求。You'll likely need fewer physical Exchange servers. This results in lower ongoing maintenance costs, fewer Exchange server licenses, and reduced rack, floor space, and power requirements.

    • 延展性已改良,因為您正將工作量分配至大量的實體電腦。在失敗期間,在剩餘的 Exchange 多角色伺服器上的負載僅會遞增地增加,這確保不會對 Exchange 伺服器上的功能帶來不利的影響。Scalability is improved, because you're distributing the workload across a greater number of physical machines. During a failure, the load on the remaining Exchange multi-role servers increases only incrementally, which ensures the other functions on the Exchange servers aren't adversely affected.

    • 恢復性已改良,因為多角色 Exchange 伺服器能自多數 Client Access 角色 (或服務) 失敗情況中倖免,並持續提供服務。Resiliency is improved, because a multi-role Exchange server can survive a greater number of Client Access role (or service) failures and still provide service.

  • 搜尋增強功能:本機搜尋執行個體現在可以讀取本機信箱資料庫複本中的資料。因此,被動搜尋執行個體不再需要與其作用中對應協調以執行索引更新,而且與舊版 Exchange 相較之下,主動複本與被動複本之間的頻寬需求已減少 40%。此外,在使用者完成搜尋項目之前,搜尋現在可以執行多個非同步磁碟讀取。這會將相關資訊填入快取,並提供線上用戶端 (例如 網頁型 Outlook) 的子第二個搜尋查詢延遲。Search improvements: The local search instance is now able to read data from the local mailbox database copy. As a result, passive search instances no longer need to coordinate with their active counterparts to perform index updates, and bandwidth requirements between the active copy and a passive copy have been reduced by 40% compared to previous versions of Exchange. Also, search is now able to perform multiple asynchronous disk reads prior to a user completing a search term. This populates the cache with relevant information, and provides sub-second search query latency for online clients like Outlook on the web.

  • 適用於網頁型 Outlook 的 Office Online Server 預覽文件預覽:在Exchange 2013 或更早的版本中,Outlook Web App 包括 WebReady 文件檢視,以對 Office 和 PDF 文件進行內建預覽。在 Exchange 2016 或更新版本中,網頁型 Outlook 使用 Office Online Server 預覽 來提供文件的豐富預覽及編輯功能。雖然這與其他產品 (例如 SharePoint 和 商務用 Skype) 提供一致的文件經驗,但是需要您將 Office Online Server 預覽 部署至內部部署環境 (如果尚未部署)。如需詳細資訊,請參閱在 Exchange 組織中安裝 Office Online ServerOffice Online Server Preview for Outlook on the web document preview: In Exchange 2013 or earlier, Outlook Web App included WebReady Document Viewing for the built-in preview of Office and PDF documents. In Exchange 2016 or later, Outlook on the web uses Office Online Server Preview to provide rich preview and editing capabilities for documents. While this provides a consistent document experience with other products like SharePoint and Skype for Business, it does require you to deploy Office Online Server Preview in your on-premises environment if you don't already have it. For more information, see Install Office Online Server in an Exchange organization.

  • MAPI over HTTP 是 Outlook 連線的預設值:MAPI over HTTP 是在 Exchange 2013 Service Pack 1 中引進,並提供傳統 Outlook Anywhere (RPC over HTTP) 連線方法的增強功能。在 Exchange 2016 或更新版本中,預設會啟用 MAPI over HTTP,並提供額外控制項,例如可以啟用或停用每位使用者的 MAPI over HTTP,以及是否向外部用戶端公告它。如需詳細資訊,請參閱 Exchange Server 中的 MAPI over HTTPMAPI over HTTP is the default for Outlook connections: MAPI over HTTP was introduced in Exchange 2013 Service Pack 1, and offers improvements over the traditional Outlook Anywhere (RPC over HTTP) connection method. In Exchange 2016 or later, MAPI over HTTP is enabled by default, and offers additional controls, such as the ability to enable or disable MAPI over HTTP per user, and whether to advertise it to external clients. For more information, see MAPI over HTTP in Exchange Server.