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ISP phone ratio's and Interoffice trunkage for voice
Fred R. Goldstein wrote in a message to Mike Bilow:
FRG> At least it's not like in the UK where they often use ODECS (18
FRG> seconds of calling, as in "octo-decimal call seconds").
I have never heard of "ODECS" before. Interesting.
FRG> Now when you have a queueing network (not relevant here), the
FRG> average queue duration is expressed as a fraction of average
FRG> call duration, per the Erlang C formula. But phone switches
FRG> block, not queue, calls.
That's functionally irrelevant: calls block, but users queue. Obviously,
queued users consume no network resources, but they do count.
FRG> Traditionally, transmission costs more than switching. But in
FRG> today's fiber optic local networks, the *incremental* cost of
FRG> transmission is very low too.
Still, costs are proportional to peak demand, and the cost of supplying peak
demand in transmission is far higher than in switching.