developing area code relief plans. NANPA also oversees the assignment of area codes, three-digit central office codes, carrier
identification codes and other numbering resources throughout the United States, Canada, Bermuda and 16 Caribbean countries.
Colaco's responsibilities for area code relief include the Midwest and Illinois.
"I must give credit to the Illinois Commerce Commission," he said. "The commission has been very effective in enlisting
certain service providers - who may have a lot of numbers in their database that are not in use - to return those numbers if
they have no plans to use them. In some cases, that has replenished telephone numbers for assignment from the telephone
service providers. It has taken the pressure off the demand."
Colaco said other forms of area code relief could be accomplished in one of two ways, an overlay or split. A split involves
a line drawn through the existing area code, where one portion keeps the number while the other half receives the new area
code. This forces about half of the population to obtain a new phone number, he said. In the split, seven-digit phone numbers
can continue to be dialed.
An overlay method allows everyone to keep his existing telephone numbers and area codes. Only when those numbers are
exhausted are new area codes assigned, Colaco said, which overlays the same territory as the original area code.
"One of the characteristics of the overlay, however, is that everyone must dial all the numbers whether it's across town or
out of state," he said.
The commission has already ruled on four of the area codes (312, 630, 708 and 773).
"The commission stated that the area code relief could be in the form of an overlay," Colaco said. "In the commission's
ruling, it states we can't avoid the mandatory 10-digit dialing when the date is set to change over. However, in this
particular case in Illinois, the commission said we would not implement 10-digit dialing until the very last number in the
underlying area code has been assigned. This prolongs the inconvenience of consumers having to dial all 10 digits."
Colaco said area code relief for the remaining numbers, 217, 618 and 815, hasn't yet been determined. There really hasn't
been a whole lot of activity on these numbers in terms of a ruling, he said. Part of the reason is that the forecast for each
of these area codes has been extended.
Each year, NANPA releases a Number Resource Utilization Forecast, based on compiled data required from the service
providers and actual assignments made in the previous year. The information is presented in a statistical model and can be
accessed on the association's Web site (www.nanpa.com).
In addition, NANPA monitors usage throughout the year and monthly reports are posted on the Web site that show actual
assignments that were made in a particular area code.
"If we see any anomalies where there might be extraordinary demand in a particular area code, we take a look at those and
see what the cause might be," Colaco said. "We constantly have our finger on that pulse of telephone number usage.
"Another reason these forecasts are extended is number conservation methods such as number pooling."
Until recently, the only method of assigning numbers to service providers was in blocks of 10,000. In a specific prefix
number, such as 635, there are 10,000 individual line numbers, he said. Following that, there would be 636, 637 and so forth
from the same service provider.
With recent changes in demand for telephone numbers, Colaco said it was necessary to create a way for the industry to
assign smaller blocks of numbers, particularly if they weren't actually using all those numbers in those databases.
"That happens a lot with smaller, rural telephone companies," he said. "In response, the industry has come up with a method
for assigning 1,000 numbers at a time to service providers."
Forecasts of area code availability can be viewed on NANPA's Web site.
staff writer: Lisa Vazzi Sciranko