We assume that ABC Corporation has two business offices. These offices are in the cities of Orlando and Atlanta. These cities are located about 450 miles apart. We assume that there are 2 employees in Orlando and 4 employees in Atlanta. Further, we assume that each employee calls the other site 4 times a day and talks for an average of 5 minutes. Further, each employee calls others in the same office 10 times a day for an average of 3 minutes. We will assume that 20% of the calls happen in the peak hours of the day. A blocking rate of 5% is acceptable for calls between the 2 sites.

a. What is the cost of PSTN (straightforward) solution?

b. Perform the Erlang calculation

c. Calculate the Blocking

d. Number of links required between these sites with respect to 5% blocking rate.

e. Number of Leased lines and PSTN lines

f. Total cost of your design

Item	Cost
Line to PSTN	$25/month
Local Call	$0.05/minute
Long distance call	$0.40/minute
PBX	$2000 purchase price
Leased line	$275/month

The cost of communications services and components