Octel Unified Messenger Concepts & Planning Guide
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Evaluating the additional load on Microsoft Exchange servers
Implementing Octel Unified Messenger affects the a ctivity of the
Exchange servers and the disk space usage.
Number of
Exchange users Use the following guidelines to estimate the effect of adding Octel
Unified Messenger to an existing Exchange environment:
nAdding Octel Unified Messenger capability to a single Exchange
mailbox is equivalent to adding approximately 30% to the s ystem
load that would otherwise be required for that mailbox.
nAdding one line of voice activity to an Exchange server affects
Exchange response time in the same way as the addition of 10
medium-activity e-mail users.
nGenerally, the load imposed by voice mail usage represents a
quarter of the load imposed by e-mail usage from the same
population. This in turn represents a 25% to 30% increase in the
required capacity of the Microsoft Exchange servers.
Example: calculation of impact on the Exchange servers capacity
nWith a hunt group of 24 lines, which covers a fully configured
Octel Unified Messenger voice server, the system is capable of
supporting approximately 16.6 Erlangs at the peak hour. This
represents a load on the Exchange system equivalent to
approximately 160 simultaneously ac tive voice mail users.
nThe 24 lines should be able to support a total voice mail
population of approximately 720 subscribers with 30 users per
line.