exchange web services in an exchange 2013 coexistence | part 1/2 | 6#23
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Exchange web services in an Exchange 2013 coexistence | Part 1/2 | 6#23 http://o365info.com/exchange-web-services-in-an-exchange-2013-coexistence-environment-part-12/ Reviewing the subject of - Exchange web services in an Exchange 2013 coexistence environment (this is the first article, in a series of two articles). Eyal Doron | o365info.comTRANSCRIPT
Page 1 of 17 | Part 06#23 | Exchange web services in an Exchange 2013 coexistence
environment | Part 1/2
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
EXCHANGE WEB SERVICES IN AN EXCHANGE
2013 COEXISTENCE ENVIRONMENT | PART
1/2 | 6#23
The purpose of the current article, is to enable us to understand better the concept
of Exchange web services in an Exchange 2013 coexistence environment.
In the current article, we will review the logic and the characters of the Exchange
web service in Exchange 2013 coexistence environment.
The article is the first of two, in which we will review the subject of Exchange web
services in an Exchange 2013 coexistence environment. The next article
is: Exchange web services in an Exchange 2013 coexistence environment | Part
Page 2 of 17 | Part 06#23 | Exchange web services in an Exchange 2013 coexistence
environment | Part 1/2
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
2/2The detailed “step by step” review of the Exchange web services, in different
Exchange 2013 coexistence environment appears in the following articles:
Exchange web services in Exchange 2013/2007 coexistence environment:
ActiveSync and Exchange web service client protocol connectivity flow in
Exchange 2013/2007 coexistence environment | 4/4
Exchange web services in Exchange 2013/2010 coexistence environment:
ActiveSync and Exchange web service client protocol connectivity flow in
Exchange 2013/2010 coexistence environment | 4/4
Article Table of content – Exchange web services in an Exchange 2013
coexistence environment | Part 1/2
Exchange web services?
Q1: What are the Exchange web services?
A1: The Exchange web services, as the name implies, are Exchange service that is
implemented as: “web-based services”. There are a couple of Exchange web
services.
An example for Exchange web service could be:
Availability service – these are the Exchange web services that enable Exchange
client to view the Free\Busy time of other Exchange recipients.
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environment | Part 1/2
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
Automatic reply – know more as the Outlook of office service, which enables
Exchange users to reply with an automatic mail message.
Mail tips – a service which enables to display “tips” for Exchange recipients based
on a specific scenario.
Who are the Exchange web service clients?
Technically speaking, each of the Exchange mail clients such as: Outlook, OWA or
ActiveSync considers is an “Exchange web service client” but the most “famous”
client is the Outlook client. Outlook client heavily depends upon the Exchange web
services for the ability of creating the Outlook mail profile and for providing
Outlook user “standard” services such as Free\Busy time, Outlook of office etc.
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environment | Part 1/2
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Who is the element that answers Exchange
mail client’s requests for Exchange web
services?
The “element” that answers the Exchange client’s requests is – Exchange server who
holds the CAS role.
As we know, in an Exchange environment, Exchange clients communicate only with
the Exchange CAS server.
Based on the Exchange client version, Exchange CAS 2013 will “decide” how to
handle the Exchange web service request.
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environment | Part 1/2
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Exchange CAS 2013 and the architecture
changes
Exchange 2013 architecture includes significantly changes that relate to the
“responsibilities” of the Exchange CAS 2013 server\role regarding the Exchange web
service component.
In former versions of Exchange (2010/2007), Exchange CAS server was responsible
for:
1. Managing and providing Exchange web service
2. “Answering” Exchange client requests for Exchange web service
Exchange CAS 2013, is responsible only for “answering” Exchange client requests
for Exchange web service, but, not for managing and providing Exchange web
service.
Page 6 of 17 | Part 06#23 | Exchange web services in an Exchange 2013 coexistence
environment | Part 1/2
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Autodiscover infrastructure & Exchange web
services
Exchange clients, access the Exchange web services by using a URL address.
The URL address that the Exchange client “needs”, is provided by the Exchange CAS
server as part of the Autodiscover information.
In simple words, to be able to address to required Exchange web services, the first
phase that the Exchange client will need to complete is: the Autodiscover step in
which he gets the required information about the existing Exchange web services
(the URL address of the existing Exchange web services) and, only after the
Exchange mail client gets this information, he has the ability to “directly” address
the Exchange server who provides a specific Exchange web service.
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environment | Part 1/2
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A more metaphorical way views the relationships that exist between the Exchange
web services, and the Autodiscover infrastructure is to view the Exchange web
services as a component that “sit on” or relies on the Autodiscover infrastructure.
The Autodiscover infrastructure is the “map” that the Exchange clients use for
locating a specific Exchange web service.
When the Exchange 2013 client needs Exchange web service, the client addresses
the Exchange CAS 2013 server and the Exchange CAS 2013 server “Proxy” the
requests for information to an Exchange Mailbox 2013 server.
When the Exchange 2010 client needs Exchange web service, the client addresses
the Exchange CAS 2013 server and the Exchange CAS 2013 “Proxy” the requests
for information to an Exchange 2010 CAS.
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environment | Part 1/2
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When the Exchange 2007 client needs Exchange web service, the client will
address directly the Exchange 2007 CAS server (without addressing the Exchange
2013 CAS).
The flow of Exchange web services
Before we start from the description of the Exchange web services in Exchange
2013 CAS and the different flow for each of the Exchange client types, let’s start
from a description of a
“Basic Exchange web services flow”.
The client protocol connectivity flow of Exchange web services is implemented as
follows:
Phase 1 – Exchange client, address Exchange 2013 CAS requesting for Autodiscover
information.
Phase 2 – Exchange CAS provides the required Autodiscover information that
includes the URL address of the exiting Exchange web services. The Exchange web
service URL address includes the FQDN (Fully Qualified Domain Name) of the
Exchange server who will provide the specific Exchange web service.
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environment | Part 1/2
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Phase 3 – Exchange client address the specific Exchange CAS server, who supposed
to provide the required Exchange web services.
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environment | Part 1/2
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Exchange CAS 2013 and the client protocol
connectivity flow of Exchange web service
The subject of Exchange CAS 2013 and his relationship with different version of
Exchange client could be quite interesting because the Exchange CAS 2013 behaves
differently with each type of Exchange client version.
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environment | Part 1/2
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For example, when we say: ”Exchange 2007 client”, we mean – Exchange client that
his mailbox is hosted at Exchange 2007 CAS, when we use the term: Exchange 2010
client, we main Exchange client, that his mailbox is hosted at Exchange 2010 CAS
etc.
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environment | Part 1/2
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In the Exchange 2013 coexistence environment, the Exchange web service client
protocol connectivity flow, is implemented differently for each of the Exchange
clients.
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environment | Part 1/2
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Exchange web service and native Exchange 2013 environment.
In a scenario of: ”native Exchange 2013 environment” when Exchange 2013
Exchange client address Exchange CAS 2013 and ask him to provide the required
Exchange web services, Exchange CAS 2013 will proxy the request to the Exchange
2013 mailbox server.
In Exchange 2013, the responsibility of managing and providing Exchange web
service “belong” to the Exchange 2013 mailbox server.
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environment | Part 1/2
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Exchange web service and legacy Exchange 2010 clients.
The client protocol connectivity flow in an Exchange 2013\2010 coexistence
environment will be based on a simple logic that was introduced in the former
section, but the main difference is that the Exchange CAS 2013 will Proxy Exchange
web service request of Exchange 2010 client to the Exchange CAS 2010 server.
Exchange CAS 2010 will generate the required information, send the information to
the Exchange CAS 2013 and the Exchange CAS 2013 will provide the “answer” the
Exchange 2010 client request.
From the Exchange 2010 client point of view, the Exchange CAS 2013 is the
“element” that provides the Exchange web service.
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environment | Part 1/2
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Exchange web service and legacy Exchange 2007 clients.
The implementation of Exchange web service in the Exchange 2013 coexistence
environment is different because in this scenario, Exchange CAS 2013 is not
involved throughout the process of providing the Exchange web service to the
Exchange 2007 client.
Exchange CAS 2007 will address Exchange CAS 2007 when they need to request for
a specific Exchange web service.
When the Exchange 2007 client gets the Autodiscover information from the
Exchange CAS 2013, the information will be “especially customized” to the “needs”
of the Exchange 2007 client.
The information will include the URL address of the Exchange CAS 2007 (using the
legacy namespace).
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environment | Part 1/2
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
When the Exchange 2007 client needs to get a specific Exchange web service, the
Exchange 2007 client will directly access the Exchange CAS 2007.
Page 17 of 17 | Part 06#23 | Exchange web services in an Exchange 2013 coexistence
environment | Part 1/2
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
The Exchange 2013 coexistence article series index page