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Traffic Engineering 625
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Ratio of phones to employees (PE): 0.75
·
Annual growth rate: 10 percent
Number of employees:
·
One year from now: 220 (200 employees
Ч 10% = 20. 200 + 20 = 220.)
·
Two years from now: 242
·
Three years from now: 266
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Four years from now: 293
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Five years from now: 322
Projected phone requirements:
·
One year from now: 165 (220 employees
Ч 0.75 PE = 165 phones)
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Two years from now: 182
·
Three years from now: 200
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Four years from now: 220
·
Five years from now: 242
Categorizing Traffic by Group
In most large businesses, it is cost-effective to apply traffic engineering to groups of trunks
serving a common purpose. For example, place inbound customer service calls into a trunk
group that is separate from general outgoing calls.
Start by separating traffic according to its direction (inbound or outbound). Next, group
outbound traffic in terms of the distance (such as local, local long-distance, intrastate, interstate,
and so on). Organizing traffic by distance is important, because most tariffs are based on
distance.
Determine the purpose of the calls. Categories could include fax, modem, call center, 800
customer service, 800 voice mail, and telecommuter.
Calculating the Number of Trunks
This section explains how to calculate how many trunks might be needed:
Step 1
Calculate CCS (per user).
Step 2
Identify a target Grade of Service (GoS). A GoS of 0.01 is
standard for most calls. Use 0.05 for tie-line services and 0.10 for
long distance.
87200333.book Page 625 Wednesday, August 22, 2001 1:41 PM