HDTenEightyP/NetNews huggingface dataset:
From: lamb@xtcn.com (Richard Lamb)
Subject: Switched 56/Switchway .vs. BRI ISDN
Organization: XtcN Ltd
Date: Thu, 17 Dec 92 18:41:53 GMT

Anyone know if the signalling schemes for the S/T ISDN BRI interface and
the DDS+secondary channel signalling used for switched 56 serivce have
any similarities ? SW56 is bipolar NRZ coding with clock encoded and every
8th bit carrying dialing info. Is S/T the same ? (not too many ways to pump
baseband bits+clock down a wire, right ?). Reason I ask is that SW56 is
avaiable anywhere and thier originally ridiculous rates are coming down
in my area (I assume in fear of ISDN).

					Thanx
					Rick
-- 
XtcN Ltd, lamb@xtcn.com, Tel:508-655-2960, FAX:508-655-4559, Telex:6504829720
11 Roxbury Ave.,Natick MA 01760,4425 Butterworth Pl.N.W.,Washington D.C. 20016
Newsgroups: comp.dcom.isdn
From: goldstein@carafe.enet.dec.com (Fred R. Goldstein)
Subject: Re: Looking for TA
Organization: Digital Equipment Corp., Littleton MA USA
Date: Sat, 19 Dec 1992 05:04:21 GMT


On Fri 04 Dec at 17:30 Lee Ziegenhals (8:7000/8@fmlynet) wrote to
> 
LZ> I'm trying to locate a BRI terminal adapter that has two 
LZ> V.35 interfaces (to support circuit-switched connections 
LZ> on both B channels simultaneously) and a separate RS-232 
LZ> dialing port.

MOtorola-UDS in Huntsville, AL has a new TA, the TA-220, which
can be provisioned with two V.35s plus separate dialing.  It
has several optional configurations, does all your usual rate
adaptations, even takes V.25bis dialing inband, etc.

---
Fred R. Goldstein   goldstein@carafe.tay2.dec.com 
k1io             or goldstein@delni.enet.dec.com   voice:+1 508 952 3274
Standard Disclaimer:  Opinions are mine alone; sharing requires permission.
Newsgroups: comp.dcom.isdn
From: deej@cbnewsf.cb.att.com (david.g.lewis)
Subject: Re: The ISDN network
Organization: AT&T
Date: Wed, 16 Dec 1992 19:42:20 GMT

In article <28624@oasys.dt.navy.mil> curt@oasys.dt.navy.mil (Curt Welch) writes:
>In a previous article deej@cbnewsf.cb.att.com (david.g.lewis) writes:
>>2. It could use a multiple-call method, first attempting a 64UDI call, and
>>if that is cleared by the network or the called customer, reattempting using
>>3.1kHz audio.
>
>In comp.dcom.isdn, bcapps@atlastele.com (Brent Capps) writes:
>>Be serious.  Given the low number of successful terminations ISDN is
>>going to achieve, you've effectively doubled the user's phone bill.
>
>Not.
>
>First, I don't know how ISDN charges work, but I doubt that you will be
>charged anything for trying to place the 64K UDI call.  The network
>will just return an error - like a busy signal - if the destination
>can't answer that type of call.  At most, I'd expect that you would be
>charged $.10.

If implemented "properly" (i.e. according to current standards), the network
should fail to complete the call, returning a DISConnect with cause value
65, Bearer Capability Not Implemented.  At least, I think that's the proper
cause value; in any case, the call should not be completed by the network.
At least in North America, it's S.O.P to not charge for uncompleted calls,
so it should cost nothing (except the incremental cost of using the
equipment for an additional failed call attempt, which for an ISDN access is
virtually 0 - it's just a D-channel message).

>Question for the ISDN experts: Can an ISDN call request a 64UDI
>service, but specify that a voice grade service is OK if 64UDI is not
>available?  Or would it have to try 64UDI, and then if that failed, try
>voice (assuming this neat sounding line database service wasn't
>available).

At the risk of claiming to be an "ISDN expert"... this capability is called
Bearer Service Fallback, and is partially standardized.  DSS1 (ISDN access)
procedures and protocols to support fallback from 64k UDI/TA (Unrestricted
Digital Information with Tones and Announcements, nee Multiuse Bearer
Service, nee 7kHz Audio Bearer Service) to 3.1kHz audio are in the 1992
CCITT recommendations and are in a T1S1 draft addendum to T1.607 (American
National Standard for ISDN access signaling).  Signaling System 7 procedures
are not yet standardized, but standardization is underway in both CCITT and
T1S1.  Also, Multiuse/64k UDI/TA with fallback is a candidate National
ISDN-3 feature.


David G Lewis                              AT&T Bell Laboratories
david.g.lewis@att.com or !att!goofy!deej     Switching & ISDN Implementation
Newsgroups: comp.dcom.isdn
From: dirk@incom.de (Dirk Koeppen)
Subject: Terminal Adapter (a/b) mit Modem
Reply-To: dirk@incom.de
Organization: Dirk Koeppen EDV-Beratung, D-6050 Offenbach, Germany
Distribution: dnet
Date: Tue, 15 Dec 1992 00:32:42 GMT

Hallo,

ich habe ewig Probleme mit meiner analogen Amtsleitung, da hier staendig die  
Leitungen nach einem Regen absaufen. Mit ISDN erhoffe ich mir jetzt bessere  
Uebertragungen und moechte ein Terminal Adapter einsetzen.

Hat jemand Erfahrung wieviel Baud ich ueber ein TA mit einem Trailblazer unter  
PEP uebertragen kann ? Zudem suche ich einen Hersteller der sofort liefern  
kann. Die Telekom kann zu Lieferzeiten keine Auskunft geben.

Vielen Dank,
dirk

--
  Dirk Koeppen  -  Holzwiesenweg 22  -  D-6050 Offenbach  -  Germany
  Phone: +49 69 89 3000 - FAX: +49 69 89 3004 - email: dirk@incom.de
  ---
  ** Phase 2 - Check Pathnames
  UNALLOCATED I=2 (NOT EMPTY) REMOVE?
From: rees@dabo.citi.umich.edu (Jim Rees)
Newsgroups: comp.dcom.isdn
Subject: Re: The ISDN network
Date: 12 Dec 1992 21:06:43 GMT
Organization: University of Michigan CITI
Distribution: world
Reply-To: Jim.Rees@umich.edu
NNTP-Posting-Host: dabo.citi.umich.edu

In article <1992Dec11.013446.24560@atlastele.com>, bcapps@atlastele.com (Brent Capps) writes:

  If you work around automated ISDN calling equipment you're going to see this
  all the time.  If I have an ISDN box that automatically delivers fax or ASCII 
  messages it's going to have a hell of a time determining on a per-call basis
  whether to deliver a message via analog or digital form.

It won't have any trouble at all.
Newsgroups: comp.dcom.isdn
From: bob1@cos.com (Bob Blackshaw)
Subject: Re: The ISDN network
Organization: Corporation for Open Systems
Distribution: usa
Date: Tue, 15 Dec 1992 14:39:00 GMT

In <lir0jeINNjkf@exodus.Eng.Sun.COM> keyman@doorway.Eng.Sun.COM (Dave Evans) writes:

>bob1@cos.com (Bob Blackshaw) writes:

>>Well, actually, your NT1 is decoding the 2B1Q line code and providing
>>some maintenance functions. The telco is under no requirement to send
>>CO battery or ringing current to the NT1. Since ISDN may some day be
>>running over fiber, they eliminated the requirement for office battery.
>>(Something to do with the difficulty of pushing 48V DC down a bit of
>>glass, I think).

>More like the RBOCs don't want to pay for the power to run everyone's
>phone anymore.

>-dAve

Well, with all those smart engineers making telephone sets that suck
up more and more power every day, why should they? Have you ever seen
the size of an average telco power plant? When you see double 6 inch
by 3/8 inch buss bars being used to route 48v DC about, you can imagine
the amperage.

After all, it is supposed to be talking (and signalling) battery, not
let's light every damn LED we can hang on this box battery.

>--
>                    * All standard disclaimers apply *
>Dave Evans      Sun Microsystems                keyman@doorway.eng.sun.com		
>W(415)336-1728

Bob.
Newsgroups: comp.dcom.isdn
From: varney@cbnewsd.cb.att.com (Al Varney)
Subject: Re: ISDN international tariffs
Organization: AT&T Network Systems, Lisle, IL, USA
Date: Sat, 19 Dec 1992 21:45:34 GMT

In article <724643806.AA00663@cswamp.apana.org.au> Arthur@cswamp.apana.org.au (Arthur Marsh) writes:
>From Australia, a voice call to the USA which is encoded by 64
>kbps PCM costs about A$1.12/minute off peak. An 64 kbps single
>ISDN B channel call to the USA using costs A$1 flagfall plus
>A$3.15 per minute.
>
>With a good modem, one can get about 1500 cps on one of these 64
>kbps PCM voice circuits.

   1500 cps in one direction...

>With one 64 kbps ISDN B channel,
>presumably 7500 cps throughput is possible, a five-fold increase
>at nearly 3 times the per-minute cost plus a big flagfall.

   Where is 7500 cps from???  You should get 64000 bps / 8-bits/c
or about 8000 cps, minus any overhead you need for error checking.
With an 8K packet and 8 c of overhead, for example, you get 7992 cps (net)
in both directions.  So it's about 1500 cps vs. about 16000 cps, or
at least a 10-fold increase.  For 3 times the price.  Sounds like a
good trade-off, if you have enough data to off-set the "flagfall".
If not, you're only talking about A$1 or two per call....

>What is the digital bandwidth difference to the telephone company
>in providing a 64 kbps B channel circuit compared with a 64 kbps
>PCM voice grade circuit?

   In the USA (and internal to some parts of Australia, I believe),
"voice" is carried at slightly less than 64 kbps -- signaling A/B
bits periodically "rob" a bit from the 8-bit PCM voice sample.  This
permits 56 kbps but not 64 kbps through the first DS-1 multiplexor.
Also, in the USA, the original DS-1 equipment suppressed an all-zero
sample to maintain internal clocking requirements (no more than 15
zero bits in a row).

>Are there other costs to the telephone company involved that
>already has ISDN capable equipment that can in any way justify
>the extra cost of ISDN?

   Switches have to recognize and route properly requests for 64 kbps
data service.  In the USA, even 56 kbps requires either dedicated MF
trunks or SS7 signaling between switches.  Data users may also require
better performance (lower bit error rate) and more maintenance attention
on the facilities.  The labor and switch updates/replacements are not
cheap.  The ability to switch echo suppressors in and out over shared
facilities could also be a cost, as could any requirement to route
64 kbps data calls over land facilities only (no satellite).

   And last, are you sure your modem call is allocated the full PCM
channel?  Many overseas calls use forms of multiplexing that share
N channels with N+m calls.  Multiplexing/compressing raw data is not
an option for 64 kbps data calls (in my opinion).

Al Varney  -- my employer owns a telecom service, but I don't work
              for that part of AT&T, nor do I speak for ANY part of AT&T.
Newsgroups: comp.dcom.isdn
From: varney@cbnewsd.cb.att.com (Al Varney)
Subject: Re: Switched 56/Switchway .vs. BRI ISDN
Organization: AT&T Network Systems, Lisle, IL
Distribution: na
Date: Fri, 18 Dec 1992 13:11:56 GMT

In article <1992Dec17.184153.17181@xtcn.com> lamb@xtcn.com (Richard Lamb) writes:
>Anyone know if the signalling schemes for the S/T ISDN BRI interface and
>the DDS+secondary channel signalling used for switched 56 serivce have
>any similarities ? SW56 is bipolar NRZ coding with clock encoded and every
>8th bit carrying dialing info. Is S/T the same ? (not too many ways to pump
>baseband bits+clock down a wire, right ?). Reason I ask is that SW56 is
>avaiable anywhere and thier originally ridiculous rates are coming down
>in my area (I assume in fear of ISDN).

   The user access portion of BRI and Switched 56 are totally different.
There are many ways to "pump bits", encode signalling and derive clock.
There were at least 6 different techniques in competition with each other
for the BRI "U" interface, and several variations of each.  Switched 56
interfaces vary with the switch manufacturer and the service provider.
For example, the 1A ESS(tm) switch 2-wire access method (called CSDC) used
the Time Compression Multiplexing (TCM) transmission mode, sending 200 bits
in one direction, adding a 16-bit guard interval, then "receiving"
200 bits from the other direction, then another 16-bit guard period.
This was all at 144 kbit/s.  The guard interval was slightly above the
time period (< 5 bits) for a pulse to travel a 20 Kft cable pair, plus
the echo time (about 5 bits) plus a 2-bit transient time.  Bridged taps
can echo somewhat beyond this time, so 16 bits was chosen.  Note that
other vendors/switches use 4-wire or other non-ISDN methods for encoding
56-kb/s data.  Maintenance mechanisms are also non-standard for 2-wire.

   On the other hand, Switched 56 interworks well with ISDN in almost
all cases.  Bellcore doesn't recognize non-ISDN data in most of the TRs,
so there may be some variation among implementations.  If the ISDN TA
recognizes 56 kb/s rate adaption and doesn't insist that the far-end
has to be "ISDN", there should be little problem interworking.  It's
certainly happening today.  I would suspect that Switched 56 rates are
falling due to competition, not a "fear" of ISDN -- most vendors and service
providers will be happy to sell you either. (I don't speak for AT&T, nor
am I privy to ANY information on rate-setting -- I find out AT&T
Communications' rates and AT&T Paradyne's new equipment/prices by
reading {Network World}, etc.)

   So if your only reason for wanting ISDN if for it's 56 kb/s bi-directional
data capability, Switched 56 is a good alternative (although as a long-term
investment, one could argue that it's likely to have less manufacturer
competition).  But don't plan on attaching a real ISDN NT or terminal to
such a line.

Al Varney -- and it is just MY opinion
Newsgroups: comp.dcom.isdn
From: "Bob Larribeau" <p00136@psilink.com>
Subject: Re: The ISDN network
Organization: Consultant
Date: Sat, 12 Dec 1992 18:13:22 GMT
X-Mailer: PSILink-DOS (3.3)

>DATE:   Fri, 11 Dec 1992 01:34:46 GMT
>FROM:   Brent Capps <bcapps@atlastele.com>
>
>So here's the situation.  I've got a modem plugged into a TA on my
>premises when a call comes in.  How do I determine whether the caller is
>analog or digital?  I can't listen for tones, because modem tone is
>supposed to be generated by the *receiving* party. 

Couple of different ways.  The CCITT standards specify that a Bearer 
Service Information Element will be included in the incoming SETUP 
message that specifies either Circuit Mode Data or Voice.  The terminal 
adapter selects the modem based on that information.

NI-1 requires separate Directory Numbers (DNs) for each B channel.  The 
voice (modem) call and the Circuit Mode Data call will be offered with 
different DNs.  The TA uses the DN to differentiate.

The CCITT approach will be supported under NI-2.  Some NI-1 switches 
will support the CCITT approach above.


>Eventually someone will even offer a digital ISDN modem, which will be 
>>cheaper to manufacture than an analog modem.

Only a question of volume which is only a question of availability and 
acceptance ...

>
>Great, what a technological leap forward that will be.  I'm so glad we
>spend billions developing and deploying ISDN so we could continue to
>communicate using modems to get our real work done.

Backward compatibility is usually a critical requirement and very expensive.


Newsgroups: comp.dcom.isdn
From: bob1@cos.com (Bob Blackshaw)
Subject: Re: The ISDN network
Organization: Corporation for Open Systems
Distribution: world 
Date: Thu, 17 Dec 1992 14:28:38 GMT

There has been much discussion about calls from ISDN to POTS here of
late and how we are to know whether to use analog or digital. This
sort of thing is covered in the CCITT Recs., but in any case you
may be sure that both the switch manufacturers and the carriers
have thought about the problem.

Lets face it, even the most optomistic person does not believe that
every exchange can be converted by tomorrow. I was told that the
AT&T 5ESS has inbuilt TA to modem pool conversion for just such an
event, and I would be very surprised if the NTI DMS series and 
Siemens EWSD are not similarly equipped. Perhaps if there are
members of these three companies in this group, they could
provide better data.

Regardless of your view or bias toward the telcos, they have been
running networks for years, so they aren't totally stupid.

$0.02

Bob.



Newsgroups: comp.dcom.isdn
From: vulture@imperial.ac.uk (Thomas Sippel - Dau)
Subject: Re: The ISDN network
Reply-To: cmaae47@imperial.ac.uk
Organization: Imperial College of Science, Technology and Medicine
Date: Mon, 14 Dec 92 16:35:54 GMT

......

-   If the straight digital asynch TA is $600 and a V.32bis modem is $400,
-   a combined modem/TA should cost $800. When the digital TA is $100
-   and the V32bis modem is $200, the combined modem/TA might still cost
-   $250.

Unfortunately this shows little understanding of the working of market prices 
and their (very tenuous) connection with production cost.

Look at the current prices of V32bis modems, then try to find out the price
for a modem WITHOUT the Hayes AT command set and be prepared for a shock.
That is, not one that does Hayes and something else and has been set up not
to reset to Hayes mode, but one where the manufacturer can guarantee you
that it will never recognise any Hayes AT command ....

The only thing you can be sure of is that if there is a "normal" piece
of equipment providing a "normal" functionality than that will be reasonably
priced, with anything else likely to cost a lot more. Even the simple 
assumption that equipment with more functionaliy at a lower price could just 
be substituted for more costly, less functional equipment by ignoring the
additional functionality does not generally hold.

- Given equal production volumes, the digital modem should be cheaper than the
- analog one, since it doesn't have to deal with nasty analog phone line
- issues like ring voltage and electrical isolation, and it doesn't need a
- hybrid or a codec.

Those "equal production volumes" will probably not come about, and if they
would, it would probably be a worst case scenario for everybody. The single
user will switch to ISDN the day he or she decides that two concurrent phone 
lines are necessary (for whatever reason), and the Telco presents a straight-
forward choice: ISDN using the currently available line for a fixed charge
or two analog lines at the very resonable cost of digging up the road for
a few miles and filling it in again (plus some overheads, of course).

Reputedly some telcos do this already, but I cannot quote a particular case.

                                     Thomas

-- 
*** This is the operative statement, all previous statements are inoperative.
*   email: cmaae47 @ ic.ac.uk (Thomas Sippel - Dau) (uk.ac.ic on Janet)
*   voice: +44 71 589 5111 x4937 or 4934 (day), or +44 71 823 9497 (fax)
*   snail: Imperial College of Science, Technology and Medicine
*   The Center for Computing Services, Kensington SW7 2BX, Great Britain
Newsgroups: comp.dcom.isdn
From: dave@philips.oz.au (David Torr)
Date: Fri, 18 Dec 92 02:13:41 GMT
Organization: Philips Public Telecommunications Systems, Melbourne, Australia
Subject: Re: Looking for TA

Arthur@cswamp.apana.org.au (Arthur Marsh) writes:

>On Fri 04 Dec at 17:30 Lee Ziegenhals (8:7000/8@fmlynet) wrote to
>All:

> LZ> From: lcz@dptspd.sat.datapoint.com (Lee Ziegenhals)

> LZ> I'm trying to locate a BRI terminal adapter that has two 
> LZ> V.35 interfaces (to support circuit-switched connections 
> LZ> on both B channels simultaneously) and a separate RS-232 
> LZ> dialing port.

>Philips produce something called the TA Multi.

>The only contact I have is the voice number +61-3-881-3725

That is the number for Philips Australia who are the local distributors. It is 
produced in Germant by PKI in Nuremberg. Phone +49 911 526 2791 Fax 526 3795. Ask for Karl-Heinz Preiss - his English is a little hard to follow!

> * Origin: Camelot Swamp MJCNA, Hawthorndene, Sth Australia
>(8:7000/8)

-- 
Dave Torr                                   dave@philips.oz.au
Software Development Manager                Tel +61 3 881 3587
Philips Public Telecommunications Systems   Fax +61 3 883 3577
Views expressed are personal and do not necessarily reflect Philips' policy.
Newsgroups: comp.dcom.isdn
From: imhw400@indyvax.iupui.edu
Newsgroups: comp.dcom.isdn
Subject: Re: The ISDN network
Date: 12 Dec 92 08:14:59 -0500

In article <7370@dove.nist.gov>, toense@cplxsys.ncsl.nist.gov (Robert E. Toense) writes:
> As for dial-in services, I would expect that they would have analog lines for
> modem service and ISDN lines for pure digital service.  The mix would be
> based on the needs of their customers and other business factors.

Don't forget the money that the telcos can make by offering modem pools to
their ISDN customers (if and when they deign to accept any) for a fee, to
facilitate connection to the digitally impaired.
-- 
Mark H. Wood, Lead Analyst/Programmer    +1 317 274 0749   [@disclaimer@]
Internet:  IMHW400@INDYVAX.IUPUI.EDU     BITNET:  IMHW400@INDYVAX
Celebrate freedom:  read a banned newsgroup.
From: Arthur@cswamp.apana.org.au (Arthur Marsh)
Newsgroups: comp.dcom.isdn
Distribution: world
Subject: Looking for TA
Date: Mon, 14 Dec 1992 17:47:50 +1000

On Fri 04 Dec at 17:30 Lee Ziegenhals (8:7000/8@fmlynet) wrote to
All:

 LZ> From: lcz@dptspd.sat.datapoint.com (Lee Ziegenhals)

 LZ> I'm trying to locate a BRI terminal adapter that has two 
 LZ> V.35 interfaces (to support circuit-switched connections 
 LZ> on both B channels simultaneously) and a separate RS-232 
 LZ> dialing port.

Philips produce something called the TA Multi.

The only contact I have is the voice number +61-3-881-3725

 * Origin: Camelot Swamp MJCNA, Hawthorndene, Sth Australia
(8:7000/8)

Newsgroups: comp.dcom.isdn
From: nelson@crynwr.com (Russell Nelson)
Newsgroups: comp.dcom.isdn
Subject: The ISDN network 
Distribution: world
Date: Fri, 11 Dec 92 17:48:46 GMT
Organization: Crynwr Software

In article <5ce56aee.1bc5b@pisa.citi.umich.edu> Jim.Rees@umich.edu writes:

   In article <1992Dec10.235056.27621@spectrum.CMC.COM>, lars@spectrum.CMC.COM    (Lars Poulsen) writes:

     If the straight digital asynch TA is $600 and a V.32bis modem is $400,
     a combined modem/TA should cost $800. When the digital TA is $100
     and the V32bis modem is $200, the combined modem/TA might still cost
     $250.

   Given equal production volumes, the digital modem should be cheaper than the
   analog one, since it doesn't have to deal with nasty analog phone line
   issues like ring voltage and electrical isolation, and it doesn't need a
   hybrid or a codec.

Ha!  What do you think your NT-1 is doing?  Those local loops are
pretty nasty.  Yes, you're paying for the functionality, you just get
to use it for both B channels at once.

-russ <nelson@crynwr.com> What canst *thou* say?
Crynwr Software           Crynwr Software sells packet driver support.
11 Grant St.              315-268-1925 Voice  |  LPF member - ask me about
Potsdam, NY 13676         315-268-9201 FAX    |  the harm software patents do.
From: rees@pisa.citi.umich.edu (Jim Rees)
Newsgroups: comp.dcom.isdn
Subject: Re: The ISDN network
Date: 15 Dec 1992 16:27:04 GMT
Organization: University of Michigan CITI
Distribution: usa
Reply-To: Jim.Rees@umich.edu
NNTP-Posting-Host: pisa.citi.umich.edu

In article <bob1.724430340@cos>, bob1@cos.com (Bob Blackshaw) writes:

  >More like the RBOCs don't want to pay for the power to run everyone's
  >phone anymore.

  Well, with all those smart engineers making telephone sets that suck
  up more and more power every day, why should they?

Because I'm paying them, that's why.  It makes a lot more sense to me for
the uninterruptible power supply to be located in the CO than in my house.
The amount of power we're talking about is not large.  The most you can draw
from the CO battery is about 1.5 watts (48v * 30ma).  If I'm off-hook all
the time, that's about 1 Kwh per month.  The phone company pays about $.10
per Kwh for power from the power company, and I'll let them have another
$.20 or so for supplying the battery plant and backup generator.  That's
still a small part of my $10 monthly phone bill.

By the way, putting more power-sucking gadgets on your phone doesn't
increase the drain from the CO battery much.  Most of the power is
dissipated in the "A" relay (or whatever it's called in these modern
electronic switches) and the local loop.
Newsgroups: comp.dcom.isdn