Do-terrestrial telephone companies regularly operate a little less full capacity of the call? It is an ordinary Monday morning in my area, but I was always greeted with "all circuits busy" message five times while trying to make a phone call this morning. Usually I only get this message immediately after a sort of earthquake or other incident that has huge locally produced. But why should I get this message on a typical day today?
Do phone companies operate regular land line just below their full capacity?
The design of any telephone switching equipment is based on a concept known as "blocking".
Blocking means - what is the% of people who have a busy signal caused by the exchange, not because their party is actually called occupied.
Most exchange models of good try to keep this number very small. As 1% or 2%
This is a significant number, 'cos exchanges today are not designed to be able to connect all the lines to all lines simultaneously. It is much more complicated than that because there are 10's of thousands of subscribers in each exchange. And the design is also based on the number of statistics on how phones are used in such a population. For times that are NOT an earthquake or tsunami or whatever.
Consider the case of an exchange for only 1,000 people needed to connect everything to everyone at all times 100%. Second, trade is expected 1000 x 1000 switches! = 1 million!
So there are models that reduce this much, but the penalty is little time for a short period of time, someone "blocked".
So ... if you have an "all lines busy" message ... Try again. Chances are you will get through soon. You just fell 2% in the population statistics for a while! : D
No, I think they had problems with local switching center.
If they regularly operate at full capacity a little less, you will get the message more frequently.
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Posted on April 7, 2010.
