wrote:

I'm not sure how the A/B switched worked.

They used different sets of channels in the 800 Mhz band.

In message , at 19:14:29 on
Tue, 3 Apr 2012, Charles Ellson remarked:
Fixed telephones outwith the "director
areas" (those like Greater London, Glasgow etc. which used the first
three letters of the exchange as the code and where the exchanges used
translation) did not have letters except by accident

I agree that (Inner) London Exchanges had three-letter abbreviations,
but very many provincial exchanges had two-letter abbreviations, plus an
index digit, as a mnemonic...

So Cheltenham was CH2 ( 0-24-2 )
Chichester was CH3 ( 0-24-3 )
Chester was CH4 ( 0-24-4 )
Chelmsford was CH5 ( 0-24-5 ) etc

Not "director areas" though. The style of the STD codes was fairly
deliberate (rather than e.g. a helpful aid for use within the GPO)

The codes I mention above are an example of the ones put in place before
STD, for GPO operators to better remember. They survived into STD
(subscriber) dialling.

but the future use of letters was dropped before STD working left the
trial stage.

I'm not sure what you are trying to say.

For example, is Chester a "director area"?
--
Roland Perry

On Mon, 2 Apr 2012 19:07:30 -0700 (PDT), wrote:

On Apr 2, 8:39*pm, bobharvey wrote:
On Apr 1, 1:08*am, wrote: Did the letters* on British telephone dials always correspond to
those of US dials?

No, see below. *As far as I recall the US, Canada, & the Philippines
were the only ones who used the US system, but ICBW.

I heard some countries may have had the Q and O in different
positions.

we had O & Q on the zero. *Nice photo athttp://www.1900s.org.uk/1940s50s-domestic-phones.htm

Ok, so when cell phones came out widely, did Britain convert to that
scheme? What about older landline Touch Tone and rotary phones--did
the dial ring have to be converted?

I'm pretty sure Britain used exchange names as the US did. When did
Britain go to all number calling? (The last US city 'converted' in
1980, but it took a long time for old habits and signage to die.)

I was driving in East Vancouver a week or so back, and noticed that
the wall of a restaurant had finally been repainted to cover over
their old signage which included "HE(mlock)" for their 43-exchange
number

On Tue, 3 Apr 2012 09:06:59 +0100, "Peter Masson"
wrote:



wrote

I'm pretty sure Britain used exchange names as the US did. When did
Britain go to all number calling?

Outside London (and other large cities) exchange names lasted into the
1980s.

.... but only dropped for public usage. The name actually generally
defined a group of exchanges**, originally those within a city or
large town but later including those satellite exchages in "linked
numbering" schemes which provided a uniform 6 (sometimes 5)-digit
numbering arrangement for all of area using main exchange name so
that local codes were disguised within the numbering or made
unneccesary once exchages were able to translate numbers.

** Using Watford (15 miles NW of London) as an example - there were
three exchanges in a 5-digit numbering scheme, each exchange being
identified (and calls routed by) the first digit 2, 3 or 4. Smaller
surrounding exchanges gradually lost their own identities as the
Watford area progressed to 6-digit numbers and modernisation of
exchange equipment let the exchanges rather than the users worry about
how a call reached another exchange in the group.

However, the letters of the exchange name were not directly used in
dialling. Long distance calls used the national dialling code for the
exchange, but local calls to a nearby exchange could use a local code
instead, and calls to the same exchange still do not need the exchange code,
only the number.

Not calls to the same exchange but calls within the same numbering
group which can still consist of several exchanges/concentrators;
local codes were abolished some years ago which in some cases means
that local calls require the full national number to be dialled (but
are still charged as local). The "director" areas continue to require
the full 7 or 8 digit number (local exchange code+local number) on
local calls except for the special case of 020 0xxx xxx numbers which
require the full national number to be dialled).

On Tue, 3 Apr 2012 09:30:21 -0700 (PDT), wrote:

On Apr 3, 9:25*am, Stephen Furley wrote:
Ok, so when cell phones came out widely, did Britain convert to that
scheme? *What about older landline Touch Tone and rotary phones--did
the dial ring have to be converted?


Sorry, I don't understand this; what does the introduction of cell
phones have to do with letters/numbers, and converting other 'phones?

The letter/number matchup on US dials/keypads has been the same since
letters were introduced in the 1920s.

I understand that historically Britain used a different matchup.

As did other European countries with their own subtle variations.
Nobody used a "standard" scheme in the international sense.

Thus, when cellphones came out with the US matchup, there was some
sort of 'conversion' between historical British practice and modern
units. That's what I'm trying to put into perspective.




I'm pretty sure Britain used exchange names as the US did. *When did
Britain go to all number calling? *(The last US city 'converted' in
1980, but it took a long time for old habits and signage to die.)
Then, businesses used the letters to give themselves memorable phone
numbers, such as TAXICAB.

[interesting history snip]

Things like your TAXICAB example were not common here. The letters
letters were not put on later dial plates, or on the rings outside
them, after all-figure numbers were introduced, so many people
wouldn't have known how to dial them. *Even in candlestick and
Bakelite days *many instruments were fitted with the 'F' versions of
the 10 and 12 dials, which did not have letters on them.
Interestingly, I've got a modern Mitel 5304 IP telephone in front of
me. *It has both a 'Z', on the 9 button, and a 'Q' on the 7 button,
whereas the 21L dial which I have at home added the Q to the 0 hole.

Before the 5304 Mitel made a similar IP model without a display, and
SIP only. *The model number of this was 5302, which probably means
something to our older American readers; a very different telephone.

Thanks for the explanation.

As mentioned, US dials stayed the same, and after exchange names were
phased out 'business names' were used. They're popular in toll free
numbers. (Amtrak is USARAIL).

Another big difference is that the US stayed at 10 digit numbers which
were introduced as the standard format in the early 1950s, but took
years to implement. Today, many callers must dial 10 digits for every
call, though some areas need only 7 if in the same area code.

(Going back some years, people in small towns had a 10-digit phone
number, but for local calls needed to dial only 5 digits.)

On Apr 3, 7:08*pm, Charles Ellson wrote:
On Tue, 3 Apr 2012 02:58:45 -0700 (PDT),
wrote:



On Apr 3, 1:14*am, Charles Ellson wrote:
On Sun, 1 Apr 2012 12:33:21 -0700 (PDT), Stephen Furley

wrote:
On Apr 1, 6:15*pm, wrote:
On Apr 1, 6:20*am, wrote:

*Letters on dials were originally to aid in dialing exchange names, eg
PEnnsylvania 6-5000 instead of 736-5000. *The US gradually
transitioned to "All Number Calling" by 1980.

I wrote a reply to this, but for some reason Google Groups won't allow
me to send it. *I'll try to send it as a reply just to you, which may
be better since it's quite long, and off-topic for this group.-

The above came through fine. *Not sure why google rejected your other
reply.

An email won't work. *This thread has already gone way off topic, so
it probably won't hurt to post it publicly. *Others may find it of
interest. *Maybe break it up into parts. *Thanks.

(Trains and telecommunications have many 'connections' in that they're
both common carriers, some of telephone technology is used for
signalling, and trains always have been heavy users of
telecommunications, including development of their own networks.)

Your post which I was trying to reply to is on Google Groups, in both
uk.railway and misc.transport.rail.americas, but does not appear in
either group in Giganews; I don't know what's going on.

The reply which I tried to send earlier was:

Somewhat different here. *0 was not used for the operator, at least
not in my time, the operator was 100. 0 was used for subscriber trunk
dialing. *I think 0 may have been used for the operator in the early
days, but that was before my time. *Normal GPO dials did not have the
word 'Operator' on them.

Older (pre-1950s?) ones did.

That's interesting, I've got serveral No. 10 dials which must be
pre-1950s, but none have the word 'Operator', and I don't think I've
seen one which did; how common were they?

There is a drawing of one in :-http://www.britishtelephones.com/dials/dialbrit.html
which looks vaguely like it has come from an old Engineering
Instruction (the extra holes implying it belonged to a Dial No.10),
and a photograph in :-http://www.telephonesuk.co.uk/miscellaneous.htm

but I've not seen one in the wild. At a rough guess there would have
been little practical necessity once automatic exchanges became
commonplace, allowing the change to 0/O matching the style and
legibility of the other characters. I have a tele 150 with IIRC a
1940s refurbishment label which has the newer style. The 1939 N
diagram accompanying one of the other dials in the above photograph
also does not show the "L" fingerplate label with "operator" on it so
it would seem to have been discarded entirely (apart from any
surviving on telephones) by then.

The photograph is interesting; it seems to be older than the normal 10
dial as on my 232 and 150, but newer than the original 10 with the
small centre; I suspect it was short-lived. The drawing of the
B(righton) plate also has 'Operator, but the photograph of a very
similar looking Brighton dial does not. Some very early GPO dials
were made by Automtic Electric in the US, but this was before the 10
was introduced. I wonder if they copied the design of an old AE plate?

On 02-Apr-12 21:25, wrote:
On Apr 2, 6:07 pm, "Adam H. Kerman" wrote:
I don't know if AT&T ever reserved area codes to any other countries for
future expansion of NANP.

Back in the _1960s_ AT&T recognized the existing area code/NNX
framework (0/1 for area codes, 2-9 NNXs) would run out and began to
program switches so that most three digit numbers could be an area
code or an exchange (as it is today). This was long before they were
actually assigned.

The original plan was that area codes would be NYN and exchanges would
be NNN (Y=0-1, N=2-9). This allowed long-distance "direct dialing" by
examining the second dialed digit: if Y, collect 8 more digits for long
distance; if N, collect 5 more digits for local.

IIRC, the issue that prompted the change was that an area code in the LA
area (213?) was running out of numbers and, rather than add a new area
code, they chose to assign NYX exchanges--breaking the scheme. This
necessitated using "1" to signify a long-distance call, which eventually
spread to the rest of the NANP. Mobile phones don't have progressive
dialing, though, so that 1 is no longer needed--and AFAIK no mobile
carrier enforces it.

There were problems when NYY and NNX area codes were added after NANPA
finally ran out of NYN area codes. NNY exchanges, which happened early
on, were a relatively minor change.

There were other patterns as well; originally, N0N was used for
states/provinces/countries with a single area code, and N1N was used for
those with multiple area codes. However, they quickly ran out of N1N
area codes and resorted to N0N area codes for the latter as well, and by
the time NYY area codes appeared, the pattern was long lost. Line
numbers starting with 9 were initially reserved for payphones, but that
rule was frequently broken and eventually disappeared, too.

S

--
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking

Nobody wrote:
"Adam H. Kerman" wrote:
Nobody wrote:

It intrigues me as to why North America cannot go to area code +
eight-digit addressing. Theoretically, you're increasing the number
availability by ten but don't have to create a new area code.

Aussie's done it, so have Brazil, Japan, France...

If planned for early enough, it could have been done if use of 0 or 1 as
the second digit was for longer line numbers. But you're misunderstanding
the situation that leads to the opening of new area codes, which is not
now, and never has been, about rapid exhaustion of line numbers.

I'm not misunderstanding anything! I know why these area codes are
required. All I'm saying is for simplicity's sake for the Average Jo
and Joe, one area code for local calling would be easier than a bunch
of disparates.

It would have been lovely if we'd stuck with most of the geography of area
codes as it existed by the late 1950's. But if we're doing things completely
differently, why must all telephone number be the same length?

Do you know how ISBNs work? They can be purchased by publishers in blocks
of 1, 10, 100, 10000, or 100000. Every element of the code varies in
length based on how many different publishers or imprints were expected
to exist in a particular country. Then the publisher or imprint decides
for itself how many numbers to buy. Anticipate lots of publishers? 1 digit
country or group code. A publisher anticipates lots of titles? Assign a
shorter registrant element to the publisher.

Each ISBN consists of 5 parts with each section being separated
by spaces or hyphens. Three of the five elements may be of
varying length:

Prefix element -- currently this can only be either
978 or 979 (it is always 3 digits).

Registration group element -- this identifies the
particular country, geographical region, or language
area participating in the ISBN system. This element
may be between 1 and 5 digits in length.

Registrant element -- this identifies the particular
publisher or imprint. This may be up to 7 digits
in length.

Publication element -- this identifies the particular
edition and format of a specific title. This may be
up to 6 digits in length

Check digit -- this is always the final single
digit that mathematically validates the rest of the
number. It is calculated using a Modulus 10 system
with alternate weights of 1 and 3.

Note that as the publishing industry was much more advanced about
item numbering than other manufacturers of retail goods, and had so
many different titles, the EAN (International Article Number) was
designed around these codes, and to avoid numbering book titles in
EAN numbering space, which would have overwhelmed the system. Instead,
an artificial country called Bookland was created, with number 978. At
first, 978 was prepended to ISBN to form the EAN, with the check digit
recalculated. Later, ISBN-10 became ISBN-13 making it the same code
as EAN. In 2005 and 2006, both ISBN-10 and -13 were shown on books.
Starting in 2007, only ISBN-13. As 978 exhausts, 979 will be used, but the
United States and other groups/countries will continue to have sufficient
code assignment space.

Suppose we'd used a system like this for telephone numbers. Then exchanges
serving areas with lower populations could have issued shorter line numbers.
If the overall number length was to be the same a la ISBN, then the small
exchange codes themselves could have been longer. A state with few exchanges
might have been assigned longer area codes. A country with a larger
population would have been assigned a shorter country code.

"If planned early enuf"? Oz, France, Brazil, Japan I doubt would've
been planning any further ahead so it cannot be that difficult to
achieve.

I'm sure there was five to ten years advance planning. There is a lot of
equipment to convert, given that telephone switches have 40 year life spans,
not to mention a lot of reprogramming in the private sector.

This is exceedingly costly.

It would however stop this "overlay" situation, e.g. here in Metro
Vancouver where 778 is overlaid on 604 and a third (236) has been
assigned for use beginning next year.

Oh, don't complain to me about overlays. My area started out with two
area codes. The smaller one got an overlay in 2007. The larger one was
split. One split was split again, then overlayed. The other split had
two codes split out, with overlays now in effect for two of the three.

We went from 2 to 10.

You want to avoid new area codes? Then force each phone company to assign
line numbers from a common pool. Use an independent lookup like LNP
to route calls to the correct network and don't rely on area code+prefix
for routing.

On 02-Apr-12 21:29, wrote:
On Apr 2, 8:05 pm, Stephen Sprunk wrote:
Note that our current ten-digit scheme allows for nearly 6.4 billion
phone numbers, which would be plenty for the 400 million people living
within the NANP if they weren't assigned so inefficiently.

It amazes me that dedicated outward trunks of a PBX get dialable
numbers even though no on ever calls them.

PBX trunks aren't numbered. However, key systems ("KTS"), which many
people mistakenly call PBXes, use normal POTS lines, not trunk circuits.
Some telcos had the ability to give multiple POTS lines the same
number, but others apparently did not--and I'm not sure how recently
that came about.

They should get specially
identified numbers (eg in the 1nn-xxxx series) so they don't waste
addressable numbers.

YXX exchanges are reserved for internal network purposes (eg. billing);
they _can't_ be assigned to customer circuits, even though it's now
possible to dial them in areas with 10-digit local calling.

I'm not sure what, if anything, YXX area codes are used for; they're not
dialable by _anyone_ on a land line.

Note that the lack of YXX exchanges is key to the planned scheme to
extend phone numbers: ABC-DEF-GHIJ will become ABC-1DEF-GHIJK (except in
Canada, where it will become ABC-0DEF-GHIJK). Once the transition is
over, and everyone is dialing 12 digits all the time, the fourth digit
will change from Y to X.

Actually, inward trunks to a PBX really need only one addressable
number, all the hunt lines could be a special series, too.

Heck, I think even in panel days a hunt group didn't need to be
consecutively numbered lines, only step demanded that.

The practice had ossified by the time it was no longer a technical
requirement. Even today, hunt groups up to 10 lines usually have a
pilot number ending in 0, and hunt groups up to 100 lines usually have a
pilot number ending in 00.

PBXes don't need (telco) hunt groups, though; trunk circuits can accept
dozens of calls to the same number. (Telco) hunt groups are only used
for KTSes.

S

--
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking

On Apr 3, 5:30*pm, wrote:
On Apr 3, 9:25*am, Stephen Furley wrote:

Ok, so when cell phones came out widely, did Britain convert to that
scheme? *What about older landline Touch Tone and rotary phones--did
the dial ring have to be converted?
Sorry, I don't understand this; what does the introduction of cell
phones have to do with letters/numbers, and converting other 'phones?

The letter/number matchup on US dials/keypads has been the same since
letters were introduced in the 1920s.

I understand that historically Britain used a different matchup.
Thus, when cellphones came out with the US matchup, there was some
sort of 'conversion' between historical British practice and modern
units. *That's what I'm trying to put into perspective.

I see what you're saying now. The fact that the Mitel IP 'phone
conforms to the same standard as cell 'phones suggests that this is
standard on all new 'phones. There was a considerable period when new
British 'phones didn't have letters at all, from the introduction of
all-figure dialing around the late '60s, until well into the push-
button era. Most of the button 'phones in my collection are 10 button
LD (pulse) models and most if not all of these lack letters, I don't
have all of them to hand to check. Many later 12 button DTMF or dual
signalling models also lack letters. Later, letters were re-
introduced, in the same pattern as on cell 'phones, which enabled
things like the TAXICAB example, but this is much less common here
than in the US. Because there was a long gap between the phasing out
of exchange names in numbers, such as ABBey 1234 and the use of
letters for other purposes the minor changes to the positions of a
couple of letters didn't really cause confusion. Most of the last
'phones to have letters on, or around, the dial would have been out of
use years before the re-introduction of letters to a slightly
different pattern, in fairly recent times.

Nobody seems to have mentioned New Zeeland, where the 0 is in the same
place, but the other digits run clockwise round the dial, so the 5 is
also in the same place, but all of the other digits are different.
The mechanism is the same as on a normal dial, so that dialing a digit
n generates 10-n pulses.

I'm pretty sure Britain used exchange names as the US did. *When did
Britain go to all number calling? *(The last US city 'converted' in
1980, but it took a long time for old habits and signage to die.)
Then, businesses used the letters to give themselves memorable phone
numbers, such as TAXICAB.

[interesting history snip]

Things like your TAXICAB example were not common here. The letters
letters were not put on later dial plates, or on the rings outside
them, after all-figure numbers were introduced, so many people
wouldn't have known how to dial them. *Even in candlestick and
Bakelite days *many instruments were fitted with the 'F' versions of
the 10 and 12 dials, which did not have letters on them.
Interestingly, I've got a modern Mitel 5304 IP telephone in front of
me. *It has both a 'Z', on the 9 button, and a 'Q' on the 7 button,
whereas the 21L dial which I have at home added the Q to the 0 hole.

Before the 5304 Mitel made a similar IP model without a display, and
SIP only. *The model number of this was 5302, which probably means
something to our older American readers; a very different telephone.

Thanks for the explanation.

As mentioned, US dials stayed the same, and after exchange names were
phased out 'business names' were used. *They're popular in toll free
numbers. *(Amtrak is USARAIL).

Another big difference is that the US stayed at 10 digit numbers which
were introduced as the standard format in the early 1950s, but took
years to implement. *Today, many callers must dial 10 digits for every
call, though some areas need only 7 if in the same area code.

(Going back some years, people in small towns had a 10-digit phone
number, but for local calls needed to dial only 5 digits.)