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ExtErlBLines()

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This function estimates the number of lines required in a trunk group if the offered traffic is known.

 

 

Format

 

=ExtErlBLines (Traffic,Blocking,Recall)

 

 

Result

 

A positive integer or zero.

 

 

Arguments

 

Name

Description

Units

Limits

Traffic

The busy hour traffic

Erlangs

Between 0 and 90,000

Blocking

The ratio of calls offered to a trunk group that can be blocked

(Unitless)

Between 0.001 and 0.500

Recall

The percentage of calls that are immediately retried if blocking is encountered

(Unitless)

Between 0 and 95

 

 

Example

 

To estimate how the lines are required for 100 Erlangs at 0.010 (1%) blocking, assuming that 20% of blocked calls are immediately retried, enter:

 

=ExtErlBLines(100,0.010,20)

 

The answer should be 118