The CAS role does not provide any message routing or message
management features. It is used to allow users of Outlook Anywhere, ActiveSync, and OWA a point of
presence. It also performs the Autodiscover and Availability service. In a standard deployment there
would be two CAS servers in the organization. Unlike Edge servers, CAS can be deployed with other
roles on the same server.
Part I: PowerShell for Exchange Fundamentals
80
Whenever a message is sent within an Exchange Server 2007 organization, it must leave the mailbox
server and be routed to a Hub Transport server. Because of this, message scanning has been removed
from the Information Store to increase stability of the database to the Hub Transport role. As a result of
this, the Hub Transport role should also be deployed in a two server minimum configuration. This
way in the event of a Hub server maintenance or if the Hub server is unavailable, there is another
Hub Transport available. The Hub role can also be installed on any Exchange server that is not an Edge
Transport or part of an MSCS cluster server.
Depending on the criticality of users being able to access their mailboxes, several options are available
for the Mailbox role. A standard deployment may use only one mailbox server. If a high - availability
option is required, Single Copy Cluster (SCC) or Continuous Content Replication (CCR) can be used to
deliver a higher level of uptime.
Pages:
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152