Lucent Technologies 101-1620-005 User Manual

Octel Unified Messenger Concepts & Planning Guide

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101-1620-005

Implementing Octel Unified Messenger affects the activity of the 
Exchange servers and the disk space usage. 

Use the following guidelines to estimate the effect of adding Octel 
Unified Messenger to an existing Exchange environment:

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Adding Octel Unified Messenger capability to a single Exchange 
mailbox is equivalent to adding approximately 30% to the system 
load that would otherwise be required for that mailbox.

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Adding 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.

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Generally, 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.

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With 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 active voice mail users.

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The 24 lines should be able to support a total voice mail 
population of approximately 720 subscribers with 30 users per 
line.