[comp.dcom.modems] Do US-made modems work in the UK?

gae@computing-maths.cardiff.ac.uk (Geraint A Edwards) (10/16/90)

If I buy a modem in the US, will it work fully on the
phone system in the UK?

Is it legal? Are the tone-diallings compatible/fully-tolerant?
Are even the plugs the same?

Has anyone any expreriences in this area (anonymity respected)
and are willing to enlighten me?

Thanks in advance,

Gedge.
  gae@uk.ac.cf.cm	Internet: gae%cm.cf.ac.uk@nsfnet-relay.ac.uk
  UUCP:     gae@cf-cm.UUCP or ...!uunet!mcsun!ukc!cf-cm!gae

tnixon@hayes.uucp (Toby Nixon) (10/18/90)

In article <1990Oct16.133001.271@computing-maths.cardiff.ac.uk>,
gae@computing-maths.cardiff.ac.uk (Geraint A Edwards) writes: 

> If I buy a modem in the US, will it work fully on the
> phone system in the UK?

I have used US modems on the UK phone system.  If you're going to be 
calling numbers in the UK and Europe rather than just calling back 
to the USA, you'll need to have a modem that has V.21 (for 300bps) 
and V.22 (for 1200bps) instead of (or in addition to) the Bell 
standards.  Both the US and Europe use V.22bis for 2400 and V.32 for 
9600.

> Is it legal? Are the tone-diallings compatible/fully-tolerant?

DTMF dialing is standardized worldwide (CCITT Recommendation Q.23). 
I'll let someone in the UK comment on whether or not it is "legal" 
to connect unapproved equipment to a UK phone circuit.  My personal 
philosophy is that it is easier to ask forgiveness than to ask 
permission!

> Are even the plugs the same?

No.  When I hooked up my modem, I used spade connectors and screwed 
directly into the back of the wall jack.  The modular connectors are 
quite different.  However, I understand that adapters are available 
at computer and phone stores in the UK.

	-- Toby

P.S.  This message should in absolutely no way be understood as 
official advice from my company.  Hayes always advises that you use 
equipment approved for sale and use in the specific country.

-- 
Toby Nixon, Principal Engineer   | Voice:   +1-404-449-8791  AT&T:  !tnixon
Hayes Microcomputer Products Inc.| Fax:     +1-404-447-0178  CIS: 70271,404
P.O. Box 105203                  | UUCP: uunet!hayes!tnixon  MCI:  267-0805
Atlanta, Georgia  30348  USA     | Internet:      hayes!tnixon@uunet.uu.net

jgh@root.co.uk (Jeremy G Harris) (10/19/90)

In article <2174@hayes.uucp> tnixon@hayes.uucp (Toby Nixon) writes:
>In article <1990Oct16.133001.271@computing-maths.cardiff.ac.uk>,
>gae@computing-maths.cardiff.ac.uk (Geraint A Edwards) writes: 
>> Is it legal? Are the tone-diallings compatible/fully-tolerant?
>
>DTMF dialing is standardized worldwide (CCITT Recommendation Q.23). 

Just because it is standardised in a CCITT Recommendation doesn't
automatically make it universally available.
Pulse dialling is usable anywhere in the UK.  Tone isn't.
-- 
Jeremy Harris			jgh@root.co.uk			+44 71 315 6600

tnixon@hayes.uucp (Toby Nixon) (10/22/90)

In article <2489@root44.co.uk>, jgh@root.co.uk (Jeremy G Harris)
writes: 

>>DTMF dialing is standardized worldwide (CCITT Recommendation Q.23). 
> 
> Just because it is standardised in a CCITT Recommendation doesn't
> automatically make it universally available.
> Pulse dialling is usable anywhere in the UK.  Tone isn't.

Fine, but that's not what he asked.  He DID ask whether DTMF was the 
same everywhere, and that's the question I answered.

Unfortunately, pulse dialing is NOT the same everywhere.  You find 
variations in the make/break ratio, pulse rate, separation between 
digits, etc.  A pulse-dial modem in the US might very well NOT work 
on a pulse-dial exchange in the UK or elsewhere.  But you can be 
pretty sure a DTMF modem WILL work.

-- 
Toby Nixon, Principal Engineer   | Voice:   +1-404-449-8791  AT&T:  !tnixon
Hayes Microcomputer Products Inc.| Fax:     +1-404-447-0178  CIS: 70271,404
P.O. Box 105203                  | UUCP: uunet!hayes!tnixon  MCI:  267-0805
Atlanta, Georgia  30348  USA     | Internet:      hayes!tnixon@uunet.uu.net

hrs1@cbnewsi.att.com (herman.r.silbiger) (10/23/90)

In article <1990Oct16.133001.271@computing-maths.cardiff.ac.uk>, gae@computing-maths.cardiff.ac.uk (Geraint A Edwards) writes:
> If I buy a modem in the US, will it work fully on the
> phone system in the UK?
> 
> Is it legal? Are the tone-diallings compatible/fully-tolerant?
> Are even the plugs the same?
> 
> Has anyone any expreriences in this area (anonymity respected)
> and are willing to enlighten me?
>

US modems will work fine in the UK, just be sure that it supports the CCITT
protocols as well as the Bell protocols.  Must current modems do.

Tone dialing is the same allo over the world.

The wall line jack requires a different plug, but thr telset jack is usually
a RJ-11.  However, instead of pins 2&3 being tip and ring, in the UK it is pins
1&4!

Herman Silbiger
hsilbiger@attmail.com
 

bruce@ccavax.camb.com (10/25/90)

In article <2263@hayes.uucp>, tnixon@hayes.uucp (Toby Nixon) writes:
> 
> Unfortunately, pulse dialing is NOT the same everywhere.  You find 
> variations in the make/break ratio, pulse rate, separation between 
> digits, etc.  A pulse-dial modem in the US might very well NOT work 
> on a pulse-dial exchange in the UK or elsewhere.  But you can be 

True, and worse yet is that WE assume that 1 pulse = 1, and 2 = 2,
and 10 = 0. But it just isn't so everywhere. Some pulsing patterns
even have less pulses for higher numbers. And I seem to recall that
not all patterns stop at 10 pulses, but go to 11 or maybe 12.

Here in the US we have 10 pps everywhere, and most anything except
the steppers can do 20 pps. That even includes some old panel COs.
Certainly x-bar and electronic offices can do 20 pps.

What I am most annoyed at Toby Nixon's company (and all the rest)
is that the modem manufacturers WON'T BOTHER TO SUPPORT 20 pps.

Touch-Tone charges are being eliminated in some places, while greedier LECs
are raising them. Here in MA, NET&T just about doubled the residential
rates for TT this month. The DPU certainly has heard testimony that TT is
now cheaper for the LEC to provide, but as someone from the LEC's
President's office accidently put it recently "We have a nice working
relationship with the DPU" then she said "whoops..." as she realised what
she had said. I think the poor folks in NYC pay something over $4 for
residential TT. You have to have a PBX trunk in most places to rate that
sort of reaming. 

Dialing at 20 pps is almost twice as fast as at 10 pps (the actual pulsing
IS twice as fast, but the interdigit time can't be halved - though generally
can be trimmed heavily). 

For those with 10 or 20 or 50 or even hundreds of modem lines, many used
inwards mostly but needing occasional outward services, the SEVERAL DOLLARS
for business TT per month really adds up as the years go by, and dialing 
at 20pps, though annoyingly slower than TT, is quite acceptable. 10 pps
is horrible.

So why won't the manufacturers give us the option of at least trying 20 pps?

david@cs.uow.edu.au (David E A Wilson) (10/25/90)

tnixon@hayes.uucp (Toby Nixon) writes:
>Fine, but that's not what he asked.  He DID ask whether DTMF was the 
>same everywhere, and that's the question I answered.

Well, not quite according to the manual for a Bit Blitzer 12E. In it it states:

	This modem has a default Tone spacing and duration of 70ms
	which may not meet the requirements of your PABX. It can be
	modified via S register 11.

	Note: To Tone Dial a Telecom Australia Public Telephone Exchange
	you should change the duration and spacing to 80ms (ATS11=80<CR>).

I am quite prepared to agree that the tone pair frequencies are standardised
but it appears that the minimum duration allowed varies.
-- 
David Wilson	Dept Comp Sci, Uni of Wollongong	david@cs.uow.edu.au

tjfs@tadtec.uucp (Tim Steele) (10/25/90)

In article <1990Oct22.235230.1401@cbnewsi.att.com> hrs1@cbnewsi.att.com (herman.r.silbiger) writes:

> In article <1990Oct16.133001.271@computing-maths.cardiff.ac.uk>, gae@computing-maths.cardiff.ac.uk (Geraint A Edwards) writes:
> > If I buy a modem in the US, will it work fully on the
> > phone system in the UK?
> > 
> > Is it legal? Are the tone-diallings compatible/fully-tolerant?
> > Are even the plugs the same?
> > 
> > Has anyone any expreriences in this area (anonymity respected)
> > and are willing to enlighten me?
> >
> 
> US modems will work fine in the UK, just be sure that it supports the CCITT
> protocols as well as the Bell protocols.  Must current modems do.
> 
> Tone dialing is the same allo over the world.
> 
> The wall line jack requires a different plug, but thr telset jack is usually
> a RJ-11.  However, instead of pins 2&3 being tip and ring, in the UK it is pins
> 1&4!

Not quite right, I'm afraid.  I posted a detailed explanation some
time ago; here's a summary.

1) The line plug is different.  In the UK, the plug is 6 pin, although
pins 1 & 6 often aren't wired.  The line is on pins 2 & 5; pin 3 is
used for earth recall (PABX) and pin 4 for anti tinkle (to suppress
phone tinkling when pulse dialling).

2) The ringing / busy tones are different, which confuses
self-righteous modems (hello Hayes!) which tends to interpret UK
ringing tone as busy, for example.

3) It is *a criminal offence* to connect a non-approved device to the
UK telephone network.  Offenders are liable to a *prison sentence*.

Tim
-- 

tjfs@tadtec.uucp        ...!uunet!mcvax!ukc!tadtec!tjfs
Tadpole Technology plc, Science Park, Milton Road, CAMBRIDGE, CB4 4WQ
Phone: +44-223-423030   Fax: +44-223-420772   Telex: 817316 TADTEC G

tnixon@hayes.uucp (Toby Nixon) (10/26/90)

In article <34272.2725ee63@ccavax.camb.com>, bruce@ccavax.camb.com
writes: 

> What I am most annoyed at Toby Nixon's company (and all the rest)
> is that the modem manufacturers WON'T BOTHER TO SUPPORT 20 pps.

Well, we've certainly considered it.  However, most countries' 
national regulations, and EIA standard 496-A in the USA, restrict 
pulse rates to between 8 and 11 pulses per second.  Granted, this is 
probably due to the need to work on old step-by-step switches, but 
it IS what the standard says.

Nevertheless, I'll bring up the subject again, using your posting as 
"ammunition".

	-- Toby

-- 
Toby Nixon, Principal Engineer    | Voice   +1-404-449-8791  Telex 151243420
Hayes Microcomputer Products Inc. | Fax     +1-404-447-0178  CIS   70271,404
P.O. Box 105203                   | UUCP uunet!hayes!tnixon  AT&T    !tnixon
Atlanta, Georgia  30348  USA      | Internet       hayes!tnixon@uunet.uu.net