Transport components shipping with Exchange 2013 Overview of Exchange 2013 Architecture Architectural improvements made in Transport History, Challenges, Improvements, Reasons for change Mail routing scenarios Built-in redundancy in Transport

AD Web browser Outlook (remote user) Mobile phone Line of business application Outlook (local user) External SMTP servers Forefront Online Protection for Exchange Enterprise Network Phone system (PBX or VOIP) Edge Transport Routing and AV/AS 2 Building Blocks Client Access Array Evolution of E2010 CAS Array Now includes, SMTP Frontend Transport Database Availability Group Now Includes, all core messaging protocols Layer 4LB CAS ArrayDAG CAS MBX

E2010Banned Server1 (V n )Server2 (V n+1 ) Protocols, Server Agents EWS RPC CA Transport Assistants MRS MRSProxy Transport Assistants EWS RPC CA MRS MRSProxy Business Logic XSO Mail Item Other APICTS XSO Mail Item Other APICTS Storage Store Content index File systemESE Store Content index File systemESE SMTP MRS proxy protocol EWS protocol

CAS For a given mailbox’s connectivity, the protocol being used is always served by the server that hosts the active database copy Each CAS determines the right end point for the traffic, and so all sessions – regardless of where they started – end up in the same place This means that the rendering for clients like OWA occurs on the Mailbox server, Transport transcoding is occurring on the Mailbox server, etc. User DAG1 MBX-A MBX-B MBX-A Layer 4LB

Handles inbound and outbound external SMTP traffic (Does not replace the Edge Transport Server Role) Handles authenticated client submissions Functions as a layer 7 proxy and has full access to protocol conversation Will not queue or bifurcate mail locally All outbound traffic to next hop appears to come from the CAS2013 Listens on TCP25 and TCP587 and TCP717 Frontend Transport SMTP Receive Protocol Agents SMTP from MBX13 External SMTP SMTP Send SMTP to MBX13 External SMTP Mailbox Selector MSExchangeFrontendTransport.exe

*previously known as Hub Transport

Processes all SMTP mail flow for the organization Will queue and route messages in and out of the organization Performs content inspection Supports extensibility in SMTP and categorizer Listens on TCP465 and TCP2525 (when co-located with CAS) or TCP25 otherwise *previously known as Hub Transport Transport SMTP to MBX-Transport Delivery SMTP from MBX-Transport Submission SMTP from CAS SMTP to CAS, MBX, HUB Delivery Agents *other protocols Submission Queue Delivery Queue Pickup/Replay Categorizer Routing Agents SMTP Send SMTP Receive Protocol Agents Edgetransport.exe

Handles mail submission and delivery from/to Store using two separate processes Does not have persistent storage Performs MIME to MAPI conversion (and vice versa) Combines Mailbox Assistant and Store Driver functionality (Supports all E2010 store driver extensibility events) Leverages local RPC for delivery to and submission from Store Does not support any extensibility SMTP from Transport Mailbox Transport SMTP Send SMTP Receive Submission Mailbox Assistants MAPI Store SMTP to Transport Submit Agents MSExchangeDelivery.exeMSExchangeSubmission.exe SMTP Send Deliver Agents Delivery SMTP to Transport

Scenario 1 – Incoming mail on a multi-role server Scenario 2 – Incoming mail on two multi-role servers Scenario 3 – Originating mail on two multi-role servers Scenario 4 – Incoming mail to a DG on separated roles Scenario 5 – Incoming mail to a legacy mailbox user Scenario 6 – Client Submission to a single unified namespace Scenario 7 – Client Submission for a legacy mailbox Scenario 8 – Transport high availability

DAG Internet or MBX2013 Server Frontend Transport receives message on port looks up where recipient’s mailbox exists and routes to a Transport service within the delivery group for that mailbox Transport receives message on port 2525 … processes it and routes it to mailbox transport delivery on server where mailbox is active Mailbox Transport Delivery receives the message on port 475 … converts MIME to MAPI and delivers message to Store. CAS 2013 Frontend Transport MBX 2013 Store Transport Mailbox Transport

Internet Frontend Transport Mailbox Transport EHLO 250OK MAIL FROM 250OK RCPT TO 250OK DATA (TLS Session) EHLO XPROXYFROM MAIL FROM 250OK RCPT TO 250OK DATA 250OK 250OK QUIT (TLS Session) EHLO XSESSIONPARAMS MAIL FROM 250OK RCPT TO 250OK DATA 250OK QUIT X-MESSAGECONTEXT

Received: from EXHV-1889.EXHV-5245dom.extest.microsoft.com (2001:4898:e8:3050:d9f3:8ace:7a2f:900b) by EXHV-1889.EXHV-5245dom.extest.microsoft.com (2001:4898:e8:3050:d9f3:8ace:7a2f:900b) with Microsoft SMTP Server (TLS) id via Mailbox Transport; Sun, 27 Jan :50: Received: from EXHV-1889.EXHV-5245dom.extest.microsoft.com (2001:4898:e8:3050:d9f3:8ace:7a2f:900b) by EXHV-1889.EXHV-5245dom.extest.microsoft.com (2001:4898:e8:3050:d9f3:8ace:7a2f:900b) with Microsoft SMTP Server (TLS) id ; Sun, 27 Jan :50: Received: from Internet ( ) by EXHV-1889.EXHV-5245dom.extest.microsoft.com ( ) with Microsoft SMTP Server (TLS) id via Frontend Transport; Sun, 27 Jan :50: Subject: Incoming mail on all-in-one role Message-ID: From:

DAG Internet Server2 CAS 2013 Frontend Transport MBX 2013 Store Transport Mailbox Transport Site Server1 CAS 2013 Frontend Transport MBX 2013 Store Transport Mailbox Transport 2 Recipients

DAG Internet Server2 CAS 2013 Frontend Transport MBX 2013 Store Transport Mailbox Transport Site Server1 CAS 2013 Frontend Transport MBX 2013 Store Transport Mailbox Transport 3 Recipients

Internet Frontend Transport Mailbox Transport

DAG Internet CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport 4 Recipients Site Boundary

DAG Internet CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport CAS 2013 Frontend Transport MBX 2013 Transport Store Mailbox Transport 5 Recipients Site Boundary E2010 Hub E2010MBX Stor e

DAG CAS 2013 Frontend Transport M1 M2 M5 M6 M3 M4 M7 M8 DAG CAS 2013 Frontend Transport M1 Site 2 M2 M5 M6 M3 M4 M7 M8 mail.fabrikam.com Region Boundary Site 1

Frontend Transport Mailbox Transport

CAS 2013 Frontend Transport DAG 1 MBX CAS 2013 Frontend Transport Site Boundary DAG 2 MBX EI4 Hub E201 0 Hub EI4 Hub E201 0 MBX mail.contoso.com

Received: from SERVER03.fabrikam.com (2001:4898:0:fff:0:5efe: ) by SERVER04.fabrikam.com (2001:4898:0:fff:200:5efe: ) with Microsoft SMTP Server (TLS) id via Mailbox Transport; Mon, 28 Jan :50: Received: from CAS.fabrikam.com (2001:4898:0:fff:200:5efe: ) by SERVER03.fabrikam.com (2001:4898:0:fff:0:5efe: ) with Microsoft SMTP Server (TLS) id ; Mon, 28 Jan :50: Received: from mail.contoso.com (2001:4898:e8:3050:d9f3:8ace:7a2f:900b) by CAS.fabrikam.com (2001:4898:dc05:24:5545:ee44:4948:d594) with Microsoft SMTP Server (TLS) id via Frontend Transport; Mon, 28 Jan :50: Received: from SERVER01.contoso.com (2001:4898:e8:3050:d9f3:8ace:7a2f:900b) by SERVER01.contoso.com (2001:4898:e8:3050:d9f3:8ace:7a2f:900b) with Microsoft SMTP Server (TLS) id ; Mon, 28 Jan :49: Received: from SERVER01.contoso.com ([fe80::d9f3:8ace:7a2f:900b]) by SERVER01.contoso.com ([fe80::d9f3:8ace:7a2f:900b%12]) with mapi id ; Mon, 28 Jan :49: From: Jerry To: Tom, Jack Subject: Scenario 3 - Originating mail

All mailflow scenarios are monitored across three transport components Each health set has multiple monitors and probes that execute synthetic transactions and assess the state of the service Responder workflows execute and alert when health sets become unhealthy

Transport has three component states – Active, Draining and Inactive. In “Active” state, a component is considered provisioned and handles user and probe traffic In “Draining” state, no new user traffic is accepted; messages queued on the server can be delivered (This state is reserved for stateful transport service only) In “Inactive” state, only monitoring probe traffic is accepted

Provides a snapshot summary of messages queued across multiple scopes – Forest, DAG, Site, Server Aggregation runs every minute and is configurable Only queues having a threshold of >=10 messages are aggregated by default Queues can be pivoted by NextHopDomain, NextHopCategory, NextHopKey, DeliveryType, Status, LastError, or ServerName properties on the queue

All three components generate to protocol, connectivity, agent and DNS new logs Transport and mailbox transport on mailbox role generate message tracking logs Transport, in addition to above, generates IRM, active user/server statistics, routing table, queue new, workload management (WLM) new and QueueQuota new