HGSCHULZ@cs.umass.edu (Henning Schulzrinne) (03/14/90)
Since there has been a recent discussion on call supervision in
Germany, I thought I'd add the experiences of a native. I was always
under the impression that calls were charged starting from the time
the other party answered - as correctly pointed out, the clock tick
method and non-itemized billing would make it close to impossible to
really check calls. However, I shared a phone once with a housemate
and we tabulated "talk" time with a specially designed kitchen timer.
Usually, we were within a unit or two of the phone bill, so that it
seems unlikely that call attempts were charged for. Also, coin phones
and the pay-after-you-talk phones in the post offices never charged
for call attempts.
[Aside: I often heard that the Bundespost, the German PTT, justified
its non-itemized billing system with privacy reasons. If you had the
data on a computer, the reasoning went, any [law enforcement agency |
hacker | your friendly, but nosy neighborhood employee of the
Bundespost ...] could potentially put together some interesting
information on lifestyles for a large number of subscribers, even
without 900 numbers. In reality, electronic offices are only now
replacing step-by-step switches, but there seems to be no general
clamoring for itemized billing. I used to be impressed when they said
that they would take a photographic image of the matrix of mechanical
counters in the central office and automatically read the numbers into
the billing computer.]
The German pay phone system deserves a special paragraph. It seems to
me one of the few items in the German phone system that could stand
being emulated around here. First, German currency makes calling from
a coin phone somewhat less of a pain. Having DM 5 coins in common
circulation (app. $3.10) avoids the agony I so vividly remember when I
tried to call home after arriving at JFK. "Deposit seven dollars and
thirty-five cents, please..." Ever tried to convince a hamburger stand
to part with thirty quarters? (Needless to say, foreign visitors don't
carry calling cards. Many countries, including Germany, do not allow
collect calls.)
But even for your everyday coin calls, the German procedure seems far
more elegant (and cheaper). If you want to make a call, you deposit
the anticipated amount into the machine. The current balance is then
displayed, more or less slowly decrementing, on a digital readout. (In
older pay phones, the coins are shown sliding down a chute, dropping
into the coinbox rather audibly.) If you see your balance approaching
zero, you either deposit more coins or hurry up your conversation.
Extra coins are refunded (but no change); leftover credit can be
applied to the next call.
Also, a basic unit of 0.30 DM (20c) provides about 40 sec of
cross-country off-peak talk time (roughly), that's often all it takes
to announce "I'll be arriving on the train at 15.42". Not much of an
incentive to use clever ringing patterns or "out-smart" automatic
operators. Also, there is no 60c+ surcharge, no operator interference,
no ringing back after call completion (but also no credit cards).
Actually, calling from a pay phone (used to be?) slightly less
expensive than using a regular home phone, since a unit (beyond the
first) costs 0.23 DM from a regular phone, 0.20 DM from a payphone.
As of last December, the rate structure worked as follows (shown in
time per unit, where unit = 0.23 DM).
M-F, 8am-6pm otherwise
local calls 8 min 12 min ("local" = same area code)
< 50 km 60 sec 2 min
50..100 km 20 sec 38 4/7 sec
> 100 km 15 sec 38 4/7 sec
Simple (and more expensive ...)
A word on area codes: Since large cities have short (2/3 digit) area
codes, but six-digit numbers, and small cities have long (4 digit)
area codes, but shorter numbers, must phone numbers work out to be
about 9 digits, not counting the initial zero indicating long
distance. (No problems with NXX area codes here.) You can actually
tell how a call is routed (if everything goes according to hierarchy)
by the area code: All cities connecting through Cologne, for example,
start with a two.
Originally, as pointed out in another recent submission, this allowed
call routing without storing (or waiting for) the whole number.
Naturally, the area code has to be instantaneously decodable, as they
say. If a city outgrows its numbering plan, it prepends a digit to all
numbers.
Henning Schulzrinne (HGSCHULZ@CS.UMASS.EDU)
Department of Electrical and Computer Engineering
University of Massachusetts at Amherst
Amherst, MA 01003 - USA === phone: +1 (413) 545-3179 (EST); FAX: (413) 545-1249