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Re: IP: Pac Bell says Net use may collapse phone system
At 10:25 AM 10/28/96 -0500, James Love wrote:
>On Mon, 28 Oct 1996, Fred R. Goldstein wrote:
> Recognizing is "more complex" than this.... does this mean that the
>residential voice network is built so that about 10 percent of the lines
>can be used at one time?
Yes, in the sense that the network (resi and others all together) is
designed with the expectation that around 10% of the resi lines are in use
Essentially, you take the number of resi lines and multiply by the average
CCS of the resi lines, the number of business lines times the average CCS of
business lines (which is higher than for resi), the number of trunks times
around 30 CCS (mostly busy), and add it all up. Thus a CO in a
business-heavy area will typically be designed for a higher CCS/line number
than one in a bedroom community.
But that's only a first-guess estimate. In practice, engineering a real CO
is done one at a time, based on experience. In other words, when it's
running out of room, you add more. The problem is that recent growth has
been fairly rapid, and telcos plan growth on a 5-10 year planning cycle.
Fred R. Goldstein email@example.com
BBN Corp. Cambridge MA USA +1 617 873 3850