Sizing Guide Exchange Server 2003 - Fujitsu

White Paper Sizing Guide Exchange Server 2003 Version: 4.2, July 2006
Network
Network quality represents an important performance factor. For example, an overloaded Ethernet segment,
in which many collisions occur, has a significant influence on performance. It is advisable to connect the
Exchange Server - depending on data volume - to the backbone through a 100-Mbit Ethernet or a gigabit
Ethernet.
If the backup is not implemented on the server on a dedicated basis but centrally through the network,
consideration must then be made for the appropriate bandwidth. In case of an on-line backup - which is the
recommended backup method, see chapter Backup - the Exchange backup API provides a data throughput
of approximately 70 GB/h which is equivalent to about 200 Mbit/s.
For a user as described in the medium profile (see chapter User profiles) an average data volume of
5 kbit/s/user is to be expected. In addition to the pure data volume, consideration must be made for the fact
that the network is loaded differently depending on the protocol used. Thus the MAPI protocol induces many
small network packets which place a greater load on the network than the few small ones that occur with the
IMAP protocol.
High availability
Availability plays a major role in large-scale Exchange server installations. If several 1000 users depend on
one single server, uncontrolled downtimes may mean sizable damage. In this case, it is recommended to
implement availability through a cluster solution, as offered by the Windows Cluster Services of Windows
Server 2003 Enterprise Edition and Windows Server 2003 Datacenter Edition. Entirely different restrictions
as regards disk subsystem and performance apply to such clusters.
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