Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.dcom.telecom > #12956 > unrolled thread

ISDN's days are numbered: What should you do? [telecom]

Back to article view | Back to comp.dcom.telecom

Contents

  ISDN's days are numbered: What should you do? [telecom] Bill Horne <malQRMassimilation@gmail.com> - 2022-05-19 13:05 +0000
    Re: ISDN's days are numbered: What should you do? [telecom] "Marco Moock" <mo01@posteo.de> - 2022-05-19 17:49 +0200
      Re: ISDN's days are numbered: What should you do? [telecom] "Grant Taylor" <gtaylor@tnetconsulting.net> - 2022-05-20 17:36 -0600
    Re: ISDN's days are numbered: What should you do? [telecom] Bill Horne <malQRMassimilation@gmail.com> - 2022-05-21 16:36 +0000
      Re: [telecom] ISDN's days are numbered: What should you do? Bill Horne <malQRMassimilation@gmail.com> - 2022-05-23 02:41 +0000
        Re: [telecom] ISDN's days are numbered: What should you do? "Fred Goldstein" <invalid@see.sig.telecom-digest.org> - 2022-05-23 08:39 -0400
          Re: [telecom] ISDN's days are numbered: What should you do? "Doug McIntyre" <merlyn@dork.geeks.org> - 2022-05-25 15:20 -0500
            Re: [telecom] ISDN's days are numbered: What should you do? Bill Horne <malQRMassimilation@gmail.com> - 2022-05-29 19:21 +0000
              Re: [telecom] ISDN's days are numbered: What should you do? "Garrett Wollman" <wollman@bimajority.org> - 2022-05-29 22:11 +0000
            Re: [telecom] ISDN's days are numbered: What should you do? "Garrett Wollman" <wollman@bimajority.org> - 2022-05-27 19:53 +0000
        Re: [telecom] ISDN's days are numbered: What should you do? "Grant Taylor" <gtaylor@tnetconsulting.net> - 2022-05-23 10:36 -0600
      Re: [telecom] ISDN's days are numbered: What should you do? "Fred Goldstein" <invalid@see.sig.telecom-digest.org> - 2022-05-22 12:11 -0400
        Re: ISDN's days are numbered: What should you do? "David" <wb8foz@panix.com> - 2022-05-28 16:12 -0400
          Re: ISDN's days are numbered: What should you do? Bill Horne <malQRMassimilation@gmail.com> - 2022-05-29 20:59 +0000
        Re: [telecom] ISDN's days are numbered: What should you do? Bill Horne <malassQRMimilation@gmail.com> - 2022-05-29 20:51 +0000
          ISDN's days are numbered: What should you do? "David" <wb8foz@panix.com> - 2022-05-30 08:50 -0400
          Re: [telecom] ISDN's days are numbered: What should you do? "John Levine" <johnl@taugh.com> - 2022-05-29 22:24 +0000
          Re: [telecom] ISDN's days are numbered: What should you do? "Grant Taylor" <gtaylor@tnetconsulting.net> - 2022-05-29 15:47 -0600
          Re: [telecom] ISDN's days are numbered: What should you do? "Garrett Wollman" <wollman@bimajority.org> - 2022-05-30 22:53 +0000
    Re: ISDN's days are numbered: What should you do? [telecom] "Michael Trew" <michael.trew@att.net> - 2022-05-20 23:40 -0400

#12956 — ISDN's days are numbered: What should you do? [telecom]

I was talking to an old friend yesterday, and he told me that he's
been working from home for a while now, and the conversation turned to
ISDN phone service, which I recommend to anyone who can still obtain
it.

This morning, while searching to find out which states, if any, still
offer ISDN Basic Rate Interface (BRI) phone lines, I came across a
story from 2016, which predicted that "BT" (I assume that's British
Telecom) would discontinue "PSTN" service in 2025.

So, I have some questions:

1. Which states still have tariffs for ISDN BRI lines?
2. Which countries still use the technology?
3. Is "BT" really going to turn off dial tones in 2025?

Curious people want to know!

https://www.computerweekly.com/blog/The-Full-Spectrum/ISDNs-days-are-numbered-What-should-you-do

--
(Please remove QRM from my email address to write to me directly)

[toc] | [next] | [standalone]

#12962

Am Donnerstag, 19. Mai 2022, um 13:05:58 Uhr schrieb Bill Horne:

> 3. Is "BT" really going to turn off dial tones in 2025?

British Telecom at least says that:
https://business.bt.com/insights/digital-transformation/uk-pstn-switch-off/

  |We're moving all our customers from the old analogue public
  |switched telephone network (PSTN) to a fully digital network. We've
  |already started. We plan to have moved everyone over before
  |Openreach stop the PSTN (and ISDN) service in 2025.

Rather interesting - they still gave offers for ISDN on their website:
https://business.bt.com/products/voice/isdn/

They also seem to switch off the analog lines (PSTN).

In Germany, Deutsche Telekom already switched off ISDN. The old PSTN
network has been replaced with ISDN equipment in the 90s and analog
lines were only available from the switching system to the customer.
They are still, but the backbone is IP-based and new contracts aren't
possible.

I don't know how PSTN is currently handled in the UK.

***** Moderator's Note *****

I'm assuming that "the old PSTN network" means "the old analog central
offices and tandem switches (e.g., Step-by-step or crossbar)," because
I think of ISDN as a "link" protocol that is served via digital
switches and tandems which carry the "Bearer" channels to their
destination in digital form, without any A-to-D or D-to-A
conversions. I think, at least in the U.S., that each Bearer channel
is still assigned to a virtual-circuit switched connection during a
phone call.

If I'm wrong, *please* post a correction!

Bill Horne
Moderator

[toc] | [prev] | [next] | [standalone]

#12965

On 5/19/22 9:49 AM, Marco Moock wrote:
> British Telecom at least says that: 
> https://business.bt.com/insights/digital-transformation/uk-pstn-switch-off/
> 
>> We're moving all our customers from the old analogue public 
>> switched telephone network (PSTN) to a fully digital network. We've 
>> already started. We plan to have moved everyone over before 
>> Openreach stop the PSTN (and ISDN) service in 2025.

I see two very key take aways from BT's statement;

1)  "old /analogue/ public switched network" --  I often see "analog" 
omitted and people just referring to the PSTN without qualification.
2)  "and ISDN" -- Seeing as how ISDN is /digital/* it's nice to have it 
called out in addition to the /analog/ (part of) the PSTN.

*Yes, I know that digital eventually depends on the analog domain.

> They also seem to switch off the analog lines (PSTN).

I'm seeing effort to switch of analog lines and ISDN in a lot of places. 
  Many places have a concerted push to eradicate POTS and / or ISDN.  -- 
  I'm using POTS in lieu of "analog PSTN".

I'm also seeing lack of effort / unwillingness to maintain POTS and / or 
ISDN more places.

> ***** Moderator's Note *****
> 
> I'm assuming that "the old PSTN network" means "the old analog central
> offices and tandem switches (e.g., Step-by-step or crossbar)," because
> I think of ISDN as a "link" protocol that is served via digital
> switches and tandems which carry the "Bearer" channels to their
> destination in digital form, without any A-to-D or D-to-A
> conversions. I think, at least in the U.S., that each Bearer channel
> is still assigned to a virtual-circuit switched connection during a
> phone call.
> 
> If I'm wrong, *please* post a correction!

I think that it's more than just Step-by-step and crossbar.  I think 
it's better summarized by thinking about what's connected to the copper 
outside plant that xLECs can viably get rid of / stop maintaining.  DSL 
being one of the last bastions that depends on at least /some/ copper 
last mile.  Even that is being transitioned to fiber in many places.

TL;DR:  My opinion is ... If it depends on copper last mile, it's 
probably on the chopping block.  It's only a matter of how long before 
it gets chopped.



-- 
Grant. . . .
unix || die

[toc] | [prev] | [next] | [standalone]

#12963

On Fri, May 20, 2022 at 11:40:00PM -0400, Michael Trew wrote:
> On 5/19/2022 9:05, Bill Horne wrote:
> >I was talking to an old friend yesterday, and he told me that he's
> >been working from home for a while now, and the conversation turned to
> >ISDN phone service, which I recommend to anyone who can still obtain
> >it.
> >
> >1. Which states still have tariffs for ISDN BRI lines?
> 
> I'm not entirely sure how to read this list, but AT&T keeps updating it.  It
> seems they have a strong push to de-regulate and remove tariffs from as many
> regions as possible.  It's been explained to me that some of these listings
> are "legacy" services, possible ISDN service.
> 
> http://cpr.att.com/pdf/dsa/zero_demand_tracker.pdf

The acronym "ISDN" doesn't appear when I search that file, but almost
all the references are to services defined in other places.

I hope some of the SME's who read this can provide both specifics and
the reasons for the "services" being removed/discontinued.

Just as one example:

- - - - - - - - - - - - -

North Carolina

All services provided under the General Subscriber Services Tariff

All services provided under the Access Services Tariff

All services provided under the General Exchange Guidebook

All services provided under the Private Line Guidebook

All services provided under the Access Guidebook, except AT&T Switched
  Ethernet Service and AT&T Dedicated Ethernet Service found in
  Section E30

- - - - - - - - - - - - -

While we're at it, someone please explain to me how "Ethernet" can be
considered a "switched" service - assuming that Winston Smitch hasn't
amended the definition of the word yet.

Bill Horne

--
(Please remove QRM from my email address to write to me directly)

[toc] | [prev] | [next] | [standalone]

#12966 — Re: [telecom] ISDN's days are numbered: What should you do?

On Sun, May 22, 2022 at 12:11:50PM -0400, Fred Goldstein wrote:
> On 5/21/2022 12:36 PM, Bill Horne wrote:
> >On 5/19/2022 9:05, Bill Horne wrote:
> >>>I was talking to an old friend yesterday, and he told me that he's
> >>>been working from home for a while now, and the conversation turned to
> >>>ISDN phone service, which I recommend to anyone who can still obtain
> >>>it.
> >>>
> >>>1. Which states still have tariffs for ISDN BRI lines?
> >>...
> 
> ISDN Basic Rate Interface (BRI) is generally no longer available in
> the US. Verizon and I think ATT long ago gave formal notice of
> discontinuance or grandfathering. Maybe Qwest, pre-Century, didn't
> bother, so it may still be on the books there. But few know how to
> provision it. Many of the switches that provided it (mainly 5ESS and
> DMS-100 in the US) no longer are in service. It was useful, especially
> for broadcasters doing remote feeds. It was better than a modem for
> Internet access, and that's what killed it as it was coming out in the
> early 1990s -- the Bells hated the Internet, which broke their
> locality-based business model, and while they couldn't attack modem
> users per se, they could at least attack the most obvious Internet
> user group, non-Centrex ISDN BRI users. Bell Atlantic l/k/a Verizon
> was also fanatical in those days about selling Centrex, and saw ISDN
> BRI as a tool for Centrex feature phones, but that was about it. That
> business has faded out too.

I don't often disagree with Fred on issues like ISDN, but I'm going to
advance a different theory: I had a chance to test an ISDN line at my
home near Boston, back around 1994 or so, and I was /very/ surprised to
find that getting a 64Kbps connection on either of the "Bearer"
channels was very difficult.

It turned out that the only solution was to redial several times, and
sooner or later I'd get a 64Kbps connection. After 15 or 20 minutes of
dialing and redialing, I might end up with two 64Kbps "Bearer"
connections to The Well, an ISP which served ISDN customers, and I
could bind them together to obtain a 128 Kbps Internet connection.

When I investigated, I quickly found out that almost all of the
T-Carrier systems connecting the central office to its Tandems were
not equipped for "8 bit clean" connections. In other words, the
connections from the CO to Tandem offices were designed for the
original T-Carrier "robbed bit" signalling paradigm, and were not
capable of delivering 64Kbps data connections.

I think Verizon - and probably the other Baby Bells - wanted to avoid
the expense of retraining a unionized workforce to make use of the
8-bit-clean fiber-optic channels just being introduced at the
time. The company would have had to retrain not only the "CO"
technicians, but also the provisioning specialists responsible for
specifying the number and type of trunks for each CO to use for each
service. Even though ISDN data calls were billed per-minute, the
accountants most likely projected more cost than revenue.

Bill

-- 
Bill Horne
(Please remove QRM from my email address if you write to me directly)

[toc] | [prev] | [next] | [standalone]

#12972 — Re: [telecom] ISDN's days are numbered: What should you do?

On 5/22/2022 10:41 PM, Bill Horne wrote:
> ...
>> ISDN Basic Rate Interface (BRI) is generally no longer available in
>> the US. Verizon and I think ATT long ago gave formal notice of
>> discontinuance or grandfathering. Maybe Qwest, pre-Century, didn't
>> bother, so it may still be on the books there. But few know how to
>> provision it. Many of the switches that provided it (mainly 5ESS
>> and DMS-100 in the US) no longer are in service. It was useful,
>> especially for broadcasters doing remote feeds. It was better than
>> a modem for Internet access, and that's what killed it as it was
>> coming out in the early 1990s -- the Bells hated the Internet,
>> which broke their locality-based business model, and while they
>> couldn't attack modem users per se, they could at least attack the
>> most obvious Internet user group, non-Centrex ISDN BRI users. Bell
>> Atlantic l/k/a Verizon was also fanatical in those days about
>> selling Centrex, and saw ISDN BRI as a tool for Centrex feature
>> phones, but that was about it. That business has faded out too.
>
> I don't often disagree with Fred on issues like ISDN, but I'm going to
> advance a different theory: I had a chance to test an ISDN line at my
> home near Boston, back around 1994 or so, and I was /very/ surprised to
> find that getting a 64Kbps connection on either of the "Bearer"
> channels was very difficult.
>
> It turned out that the only solution was to redial several times, and
> sooner or later I'd get a 64Kbps connection. After 15 or 20 minutes of
> dialing and redialing, I might end up with two 64Kbps "Bearer"
> connections to The Well, an ISP which served ISDN customers, and I
> could bind them together to obtain a 128 Kbps Internet connection.
>
> When I investigated, I quickly found out that almost all of the
> T-Carrier systems connecting the central office to its Tandems were
> not equipped for "8 bit clean" connections. In other words, the
> connections from the CO to Tandem offices were designed for the
> original T-Carrier "robbed bit" signalling paradigm, and were not
> capable of delivering 64Kbps data connections.
>
> I think Verizon - and probably the other Baby Bells - wanted to avoid
> the expense of retraining a unionized workforce to make use of the
> 8-bit-clean fiber-optic channels just being introduced at the
> time. The company would have had to retrain not only the "CO"
> technicians, but also the provisioning specialists responsible for
> specifying the number and type of trunks for each CO to use for each
> service. Even though ISDN data calls were billed per-minute, the
> accountants most likely projected more cost than revenue.

The 64-kbit data bearer service was, as you note, not widely
available.  For it to work, both the transmission systems and the
switching systems needed to implement the B8ZS fix to the T1 carrier
system specification.  And yes, NYNEX was full of old line cards that
only did the not-clean old AMI format. They had upgraded some of the
switches to have ISDN but didn't update the trunk network. Also, the
inbound ports needed ISDN PRI, which they were initially slow to roll
out. They treated ISDN data as "Switched 56", an older data service
that accommodated robbed-bit signaling. That was where their tariff
came from too, at 8c/minute for data calls.

There was a work-around, though. I always used "data over voice bearer
service" (DOVBS), wherein the network was told it was a voice call and
the terminal gear only used the clean 7 bits, for a 56k connection.
That not only worked well, but took advantage of the flat rate voice
calls on residential lines. Those calls could also terminate into a
modem pool that was not on ISDN PRI, just on the older robbed-bit T1
trunk service.  When I was setting up DEC's ISDN trial circa 1993,
they actually told us to do that, as they had no other way to deliver
the calls.

-- 
Fred R. Goldstein      k1io     fred "at" ionary.com
  +1 617 795 2701


***** Moderator's Note *****

For some reason, "DOSBS" (Data Over Speech Bearer Service) was a taboo
subject by 1994: the ISP's that supported ISDN connections all
pretended that they had never heard of it, and "bonding," even with 56
Kbps *DATA* calls, was likewise a mystery.

Bill Horne
Moderator

[toc] | [prev] | [next] | [standalone]

#12984 — Re: [telecom] ISDN's days are numbered: What should you do?

"Fred Goldstein" <invalid@see.sig.telecom-digest.org> writes:
>The 64-kbit data bearer service was, as you note, not widely
>available.  For it to work, both the transmission systems and the
>switching systems needed to implement the B8ZS fix to the T1 carrier
>system specification.

As one who had to troubleshoot ISDN calls failing.
In my area (Minneapolis), I found 64k bearer calls went through more
than 98% of the time.

When those 2% failures came through, I would have to do the cycle
through the almost always CLEC's supportsystems, get them to trap the calls,
and get them to figure out which trunk was marked as 8-bit clean, but
only could handle the 7-bit channels.

To me, it didn't seem like they were purposely not upgrading anything,
just that the 7-bit trunks weren't marked correctly in the switch
database, so that when 64k calls wanted to go through, the switch
incorrectly put them on a 7-bit trunk.

The fix almost always was for the CLEC techs to mark the trunk
properly in the switch database, and there were plenty of 8-bit clean
trunks to use, when they were marked correctly so 64k calls could
properly route through the COs. 

Telecom Digest Moderator wrote:
>For some reason, "DOSBS" (Data Over Speech Bearer Service) was a taboo
>subject by 1994: the ISP's that supported ISDN connections all
>pretended that they had never heard of it, and "bonding," even with 56
>Kbps *DATA* calls, was likewise a mystery.

Since 64k calls went through at least 98% successful in this area, and
in this area, voice & data were all flat-rate billed, there wasn't any
point to do the data over speech calls. I don't remember having to
support anything special to make it happen, but then we didn't really
have any reason to have to do that in the first place, so I don't
remember what it took to happen.

We always did 128k bonded connections with no issues. No mystery here.
The biggest problem was the customer equipment. Most of it sucked
hard.

-- 
Doug McIntyre
doug@themcintyres.us

[toc] | [prev] | [next] | [standalone]

#12988 — Re: [telecom] ISDN's days are numbered: What should you do?

On Fri, May 27, 2022 at 07:53:56PM -0000, Garrett Wollman wrote:
> In article <O8SdnfjNCtEMEhP_nZ2dnUU7-LHNnZ2d@giganews.com>,
> Doug McIntyre <merlyn@dork.geeks.org> wrote:
> 
>> We always did 128k bonded connections with no issues. No mystery
>> here.  The biggest problem was the customer equipment. Most of it
>> sucked hard.
>
> In the early part of my career, I supported ISDN connections for staff
> and faculty in my lab.  This was before widespread cable ISP access
> and overbuilding, but Bell Atlantic (as then was) had a special tariff
> that allowed universities to get unmetered ISDN BRI lines installed at
> employees' homes.  We used Ascend equipment to terminate a PRI in our
> building, which also supported model dial-up.  Normally we'd use a
> smaller Ascend box (smaller than my current cable modem!) on the
> residential end, and we'd configure it to nail up both B channels 24x7
> and give each user a subnet.

[snip]

I'm going to have to descend from whatever foothold I used to have on
Mount Olympus, and admit that I don't understand how you could "nail
up" two bearer channels without disabling the ISDN line's capability
to carry phone calls. Were the ISDN lines used only for data service,
or could the Bearer channels be divorced while a phone call was in
progress?

-- 
Bill Horne
(Remove QRM from my email address to write to me directly)

[toc] | [prev] | [next] | [standalone]

#12995 — Re: [telecom] ISDN's days are numbered: What should you do?

In article <20220529192147.GA29678@telecom.csail.mit.edu>,
Bill Horne  <malQRMassimilation@gmail.com> wrote:

>I'm going to have to descend from whatever foothold I used to have on
>Mount Olympus, and admit that I don't understand how you could "nail
>up" two bearer channels without disabling the ISDN line's capability
>to carry phone calls.

We did not provide staff members' voice service, only the data
connection to our lab.

When the ISDN service ended, it was convenient for those of us who
switched to CLEC ADSL to have that extra known-clean pair to our
homes; folks who were trying to run ADSL on top of an existing
unbundled ILEC voice circuit had a much harder time with installation
and a great deal of finger-pointing between the two carriers.

(Of course now we all have our Internet connectivity via DOCSIS, and
much of this region -- although not Cambridge -- has three competing
facilities-based carriers, Comcast, RCN, and Verizon FiOS.)

-GAWollman

-- 
Garrett A. Wollman    | "Act to avoid constraining the future; if you can,
wollman@bimajority.org| act to remove constraint from the future.  This is
Opinions not shared by| a thing you can do, are able to do, to do together."
my employers.         | - Graydon Saunders, _A Succession of Bad Days_ (2015)

[toc] | [prev] | [next] | [standalone]

#12996 — Re: [telecom] ISDN's days are numbered: What should you do?

In article <O8SdnfjNCtEMEhP_nZ2dnUU7-LHNnZ2d@giganews.com>,
Doug McIntyre <merlyn@dork.geeks.org> wrote:

>We always did 128k bonded connections with no issues. No mystery here.
>The biggest problem was the customer equipment. Most of it sucked
>hard.

In the early part of my career, I supported ISDN connections for staff
and faculty in my lab.  This was before widespread cable ISP access
and overbuilding, but Bell Atlantic (as then was) had a special tariff
that allowed universities to get unmetered ISDN BRI lines installed at
employees' homes.  We used Ascend equipment to terminate a PRI in our
building, which also supported model dial-up.  Normally we'd use a
smaller Ascend box (smaller than my current cable modem!) on the
residential end, and we'd configure it to nail up both B channels 24x7
and give each user a subnet.

We were still doing this in 2001 when I bought my condo, so I was
probably one of the only residential ISDN customers in my town.  The
special rate was detariffed around 2003 so I had the former ISDN pair
ported to Speakeasy for ADSL service.  Shortly thereafter, we made the
decision to stop supporting our own dial-in and retired the PRI and
modems.  (It took only a few years after that to get to the point
where employees were simply expected to pay for their own Internet
connectivity, rather than getting reimbursed for it -- likewise cell
phones.)

-GAWollman

-- 
Garrett A. Wollman    | "Act to avoid constraining the future; if you can,
wollman@bimajority.org| act to remove constraint from the future.  This is
Opinions not shared by| a thing you can do, are able to do, to do together."
my employers.         | - Graydon Saunders, _A Succession of Bad Days_ (2015)

***** Moderator's Note *****

My apologies to Garrett: this was supposed to have been published last
week, but it got stuck in a holding file for some reason.

Bill Horne
Moderator

[toc] | [prev] | [next] | [standalone]

#12975 — Re: [telecom] ISDN's days are numbered: What should you do?

On 5/22/22 8:41 PM, Bill Horne wrote:
> When I investigated, I quickly found out that almost all of the 
> T-Carrier systems connecting the central office to its Tandems were not 
> equipped for "8 bit clean" connections. In other words, the connections 
> from the CO to Tandem offices were designed for the original T-Carrier 
> "robbed bit" signalling paradigm, and were not capable of delivering 
> 64Kbps data connections.

This seems to be directly related to the type of bearer channel /needed/ 
to support the type of call being placed.

E.g. /data/ was supposed to be 64 kbps / 8-bit clean from TA to TA all 
the way through the network.  Conversely, /voice/ and / or /audio/ calls 
(terms are slightly different) could use 56 kbps or even analog trunks 
somewhere in the middle of the network.

My understanding is that 64 kbps / 8-bit clean calls are supposed to 
refuse to establish over an impure intermediate transit between two 
switches.



-- 
Grant. . . .
unix || die

[toc] | [prev] | [next] | [standalone]

#12968 — Re: [telecom] ISDN's days are numbered: What should you do?

On 5/21/2022 12:36 PM, Bill Horne wrote:
> On 5/19/2022 9:05, Bill Horne wrote:
>>> I was talking to an old friend yesterday, and he told me that he's
>>> been working from home for a while now, and the conversation turned to
>>> ISDN phone service, which I recommend to anyone who can still obtain
>>> it.
>>>
>>> 1. Which states still have tariffs for ISDN BRI lines?
>> ...

ISDN Basic Rate Interface (BRI) is generally no longer available in
the US. Verizon and I think ATT long ago gave formal notice of
discontinuance or grandfathering. Maybe Qwest, pre-Century, didn't
bother, so it may still be on the books there. But few know how to
provision it. Many of the switches that provided it (mainly 5ESS and
DMS-100 in the US) no longer are in service. It was useful, especially
for broadcasters doing remote feeds. It was better than a modem for
Internet access, and that's what killed it as it was coming out in the
early 1990s -- the Bells hated the Internet, which broke their
locality-based business model, and while they couldn't attack modem
users per se, they could at least attack the most obvious Internet
user group, non-Centrex ISDN BRI users. Bell Atlantic l/k/a Verizon
was also fanatical in those days about selling Centrex, and saw ISDN
BRI as a tool for Centrex feature phones, but that was about it. That
business has faded out too.

ISDN Primary Rate Interface (PRI), which runs over a DS-1 ("T1")
channel, is still out there, though again its number are in
decline. It is a very good trunk interface for PBX systems, and many
different 1995-2010 vintage switching systems support it, as it
handled the dial-up era's modem pools. But most newer systems use SIP
trunks instead. PRI has higher quality of service than SIP/RTP/IP, but
the industry has moved away from it, as the higher-volume IP services
usually have a lower price tag.

-- 
Fred R. Goldstein      k1io     fred "at" ionary.com
  +1 617 795 2701

[toc] | [prev] | [next] | [standalone]

#12989 — Re: ISDN's days are numbered: What should you do?

Fred Goldstein said:

 > ISDN Basic Rate Interface (BRI) is generally no longer available in
 > the US.
...

 > But few know how to provision it. Many of the switches that
 > provided it (mainly 5ESS and DMS-100 in the US) no longer are in
 > service.

I suspect that last sentence is a major aspect. VZ at least is
actively working to get rid of their 5ESS's. A benefactor of their
recent buyout told me that the ongoing software charges were
"onerous"....

[toc] | [prev] | [next] | [standalone]

#12990 — Re: ISDN's days are numbered: What should you do?

On Sat, May 28, 2022 at 04:12:50PM -0400, David wrote:
> Fred Goldstein said:
> 
> > ISDN Basic Rate Interface (BRI) is generally no longer available in
> > the US.
> ...
> 
> > But few know how to provision it. Many of the switches that
> > provided it (mainly 5ESS and DMS-100 in the US) no longer are in
> > service.
> 
> I suspect that last sentence is a major aspect. VZ at least is
> actively working to get rid of their 5ESS's. A benefactor of their
> recent buyout told me that the ongoing software charges were
> "onerous"....

It must be the heat: I'm just not getting the subtext of messages today.

"A benefactor of " ... *whose* recent buyout, of whom?

What software charges? Do you mean the fees charged for the version of
Unix used in the 5E switch? Come to think of it, who owns that switch
design now?

Bill, who is still feeling old. 

-- 
Bill Horne
(Please remove QRM from my email address to write to me directly)

[toc] | [prev] | [next] | [standalone]

#12991 — Re: [telecom] ISDN's days are numbered: What should you do?

On Sun, May 22, 2022 at 12:11:50PM -0400, Fred Goldstein wrote:
>> On 5/19/2022 9:05, Bill Horne wrote:
>>>> I was talking to an old friend yesterday, and he told me that
>>>> he's been working from home for a while now, and the conversation
>>>> turned to > >>>ISDN phone service, which I recommend to anyone
>>>> who can still obtain it.
>>>> 
>>>> 1. Which states still have tariffs for ISDN BRI lines?
> 
> ISDN Basic Rate Interface (BRI) is generally no longer available in the US.
> Verizon and I think ATT long ago gave formal notice of discontinuance or
> grandfathering. Maybe Qwest, pre-Century, didn't bother, so it may still be
> on the books there. But few know how to provision it. Many of the switches
> that provided it (mainly 5ESS and DMS-100 in the US) no longer are in
> service. It was useful, especially for broadcasters doing remote feeds. It
> was better than a modem for Internet access, and that's what killed it as it
> was coming out in the early 1990s -- the Bells hated the Internet, which
> broke their locality-based business model, and while they couldn't attack
> modem users per se, they could at least attack the most obvious Internet
> user group, non-Centrex ISDN BRI users.

This is twice in one day that I've had to take a step downward from my
place on Mount Olympus, and I fear I might turn into Sisyphus if I
don't - pun intended - watch my step. ;-)

Why would the bells hate the Internet? To be sure, their business
model was built around central offices which each served a rate
center, but how could they have predicted and/or anticipated the
development of VoIP? Did Mother Bell see /any/ data transmission
method as a threat? Why?

The Baby Bells knew that Cellular was coming, and I'd bet they knew it
would displace copper-served POTS within time we've had to see it
happen. Still, I just don't remember the leaders of the Baby Bells as
being such long-term thinkers. The Internet hasn't replaced their
locality-based feeding trough: we still have and use phone numbers,
and even if a cell call has to be routed using VoIP and/or SIP trunks,
the savings in billing offered by "Free" long-distance would have more
than offset the cost of adapting to new trunking paradigms.

> Bell Atlantic l/k/a Verizon was also fanatical in those days about
> selling Centrex, and saw ISDN BRI as a tool for Centrex feature
> phones, but that was about it. That business has faded out too.

I wonder why? What was so different between the business models of the
1990's and those of the 2020's that Centrex would no longer be a
cost-saver for firms which chose to use it? Granted, the Coronavirus
has caused a reexamination of work-at-home as a viable real-estate
strategy, but I think the /time/ spent on dialing, connecting, and
suffering with the shortcomings of cellular calls, like picket-fencing,
fading, disconnecting, and - last but far from least - being easily
tapped by anyone with an antenna ana a few items of listening
equipment.
 
> ISDN Primary Rate Interface (PRI), which runs over a DS-1 ("T1") channel, is
> still out there, though again its number are in decline. It is a very good
> trunk interface for PBX systems, and many different 1995-2010 vintage
> switching systems support it, as it handled the dial-up era's modem pools.
> But most newer systems use SIP trunks instead. PRI has higher quality of
> service than SIP/RTP/IP, but the industry has moved away from it, as the
> higher-volume IP services usually have a lower price tag.

I'm afraid comparing IP-based telephony to ISDN PRI links is the
ultimate race-to-the-bottom in voice communicaiton. As far as I can
tell, the only thing that makes SIP or VoIP or /any/ Internet-based
real-time service - don't forget streaming video - viable is a surplus
of bandwidth which will, inevitably, decline as paid-prioritization
methods and equpment take hold.

Bill, who is feeling old and out-of-step. 

-- 
Bill Horne
(Please remove QRM from my email address in order to write to me directly)

[toc] | [prev] | [next] | [standalone]

#12992 — ISDN's days are numbered: What should you do?

First, my source was a VZ employee who accepted their buyout offer to 
reduce manpower, and left. Second, the charges he mentioned are the 
ongoing application software (called a "Generic") license fees on a 
5ESS. The operating companies didn't just pay WECO to buy the hardware, 
they also had stiff ?monthly/yearly? license fees to use the 5ESS 
Generic that made them work.

 > Why would the bells hate the Internet?

The Bell's were welded to their "If only we can charge local calls by 
the minute, it would be great..." thinking.

They hated dialup, be it POTS or ISDN, because it shredded their
predicted call durations, utilization of switch resources and 
interoffice trunkage.

People like me would make one 9c call, and leave it up. I had calls that 
would stay up for 999 hours before my router would drop the call when it 
reached 1000.

PLUS:
Ma Bell had anticipated that CLEC-fed businesses would call LEC-served 
residences. Under Her insistence, the originating {C}LEC would pay the 
terminating {C}LEC compensation per minute.

But the ISP's, soon tired of dealing with LEC's unwilling/unable to make 
large dial-in modem pools function, switched to CLEC's who would help 
them. So instead of an income stream, it was a huge drain. Fred 
Goldstein can likely comment on the ensuing legal fights.

Centrex:
I don't know if is less popular it is now than it was, but in the DC 
region, it was a major LEC income stream. The reason is only the tiniest 
USGovt agency fits into one building; most are spread out between many, 
often scattered between DC, MD & VA locations. Centrex gave them 4 or 5 
digit calling between all their offices. Further, ISDN Centrex gave the 
boss a fancy feature phone with many buttons, vs. a POTS 2500 set.

[toc] | [prev] | [next] | [standalone]

#12993 — Re: [telecom] ISDN's days are numbered: What should you do?

According to Bill Horne  <malassQRMimilation@gmail.com>:
> On 22 May 2022 12:11:50 -0400, Fred Goldstein wrote:
>> IT was better than a modem for Internet access, and that's what killed it as it
>> was coming out in the early 1990s -- the Bells hated the Internet, which
>> broke their locality-based business model, and while they couldn't attack
>> modem users per se, they could at least attack the most obvious Internet
>> user group, non-Centrex ISDN BRI users.

>Why would the bells hate the Internet?

No per minute charges (other than what they could try to get for ISDN calls),
no separations, no "value" pricing.  It totally broke their business model.
This was way before VoIP, they wanted data to pay by the minute too.

>I wonder why? What was so different between the business models of the
>1990's and those of the 2020's that Centrex would no longer be a
>cost-saver for firms which chose to use it?

Phone switches have gotten a lot cheaper, wires haven't.  Putting a PBX
in the customer's office is a lot cheaper than running every extension
back to the CO.  I realize there were versions of Centrex that put the
switch on the client's premises but now it's just an expensive telco
managed PBX.

R's,
John
-- 
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

[toc] | [prev] | [next] | [standalone]

#12994 — Re: [telecom] ISDN's days are numbered: What should you do?

On 5/29/22 2:51 PM, Bill Horne wrote:
> Why would the bells hate the Internet?

I don't /know/ why.  But I have a few speculations:

  - Not Invented Here (bells)
  - Bells tended to be EXTREMELY /circuit/ switched, which is
    diametrically opposed to /packet/ switched.
  - Bet on the wrong horse.
  - Had to double down on any of the above.

> To be sure, their business model was built around central offices 
> which each served a rate center, but how could they have predicted 
> and/or anticipated the development of VoIP? Did Mother Bell see /any/ 
> data transmission method as a threat? Why?

I think it would be rather naive to think that /nobody/ saw the
possibility of the Internet making things over a disparate distance
equal cost to access vs the distance based billing of local vs long
distance.

> I wonder why? What was so different between the business models of 
> the 1990's and those of the 2020's that Centrex would no longer 
> be a cost-saver for firms which chose to use it?

I don't know of /any/ /single/ ILEC employee ever talking about
Centrex.  I think they had decided that Centrex was an unwanted step
child by the 2000s when I was working on phone systems (PBXs / KSUs /
""Smart (read: dumb) phones / multi-line POTS).  If I had known about
Centrex and the pricing would have been acceptable, I probably would
have done more with it.

> Granted, the Coronavirus has caused a reexamination of work-at-home as 
> a viable real-estate strategy, but I think the /time/ spent on dialing, 
> connecting, and suffering with the shortcomings of cellular calls, 
> like picket-fencing, fading, disconnecting, and - last but far from 
> least - being easily tapped by anyone with an antenna ana a few items 
> of listening equipment.

I don't do enough on cell to be able to comment.  But I can say that
my recent messing with ISDN vs POTS in my house, the call connection
speed of ISDN is -- in a word -- /amazing/ to me compared to POTS.

> I'm afraid comparing IP-based telephony to ISDN PRI links is the 
> ultimate race-to-the-bottom in voice communicaiton. As far as I can 
> tell, the only thing that makes SIP or VoIP or /any/ Internet-based 
> real-time service - don't forget streaming video - viable is a surplus 
> of bandwidth which will, inevitably, decline as paid-prioritization 
> methods and equpment take hold.

I think that VoIP /across/ /the/ /Internet/ is a questionable idea at
best.  I also think that VoIP technology across the LAN is a very good
technology.  Especially if you have the LAN switches that can isolate
& prioritize VoIP.

With this in mind, both ISDN PRI and VoIP are communications protocols
which imply an underlying network.  The former seems to be a vertical
market while the latter seems to be used ~> abused for anything and
everything.

I'm aware of some larger SIP trunks, which have supplanted ISDN PRI
trunks, that are using dedicated access circuits.  As such the
dedication means that there will always be sufficient bandwidth.

-- 
Grant. . . .
unix || die

[toc] | [prev] | [next] | [standalone]

#13003 — Re: [telecom] ISDN's days are numbered: What should you do?

In article <20220529205126.GA30139@telecom.csail.mit.edu>,
Bill Horne  <malassQRMimilation@gmail.com> wrote:

>Why would the bells hate the Internet? To be sure, their business
>model was built around central offices which each served a rate
>center, but how could they have predicted and/or anticipated the
>development of VoIP?

Voice over IP -- indeed, *multiparty* voice over IP -- was already a
thing by the early 1990s, before most people had Internet access at
all.  The problem, as it was then conceived, was that there wasn't a
whole lot of bandwidth available on inter-network links.  The NSFnet
had just upgraded from 56k to T-1 to T-3 over a very short period, and
while people thought that a whole 45 Mbit/s was an *enormous* amount
of bandwidth, that was still only 690 simultaneous point-to-point
voice connections (assuming the routing actually worked out).
Videoconferences were even more bandwidth-intensive.

The folks I worked for in my first job out of college had a research
program called "ISIP" -- "Integrated services Internet Protocol" --
that was trying to figure out how to fix that, by providing both
aggregate service guarantees and individual, per-flow resource
reservations to the Internet architecture, and by translating those
service requests into something that could be provided by the actual
lower-layer network technologies.  That involved quite a bit of
standardizing service definitions, so that you could programmatically
give a service request to a network provider and they could tell you
yes-or-no whether they could service the request and how much it would
cost.  (This was what they hired me to work on, although it's largely
not what I actually ended up doing.)

Per-flow resource reservations over a public network turned out ot be
an intractable problem, for reasons that were part technical and part
economic.  (The PSTN was able to make it work by effectively only
providing one flavor of service, constant-bit-rate switched circuits.)
The economic reason, which was obvious even in the late 1990s, was
that (unlike the cooperative ARPANET and NSFnet, which were funded by
a single body for a unitary purpose), the commercial Internet
consisted of many mutually distrustful parties whose economic
interests were adversarial to one another.  (By 2000 there were big
controversies about some large providers using their market power to
impose a settlements regime on smaller carriers, when in the early
days, providers exchanged traffic over neutral, settlement-free
exchange points.)  In order to implement anything like resource
reservations, or even differentiated services, over the public
Internet, you needed interdomain capacity reservations, and that
wasn't in any provider's interest to implement at a cost customers
were willing to pay.

What really killed this line of R&D, however, was the dot-com bubble
of the late 1990s.  Suddenly, the newly commercialized Internet was
*awash* in bandwidth, as everyone who had the VC money to burn
invested in burying dark fiber in every right-of-way imaginable.
There was no need to worry about resource scarcity, because if
bandwidth was a problem, it was just a matter of swapping out the
transceivers and suddenly you had double, triple, even ten times the
bandwidth as before.  Resource reservation is something you need
contol latency when you're trying to maximize utilization of a limited
resource;[1] it doesn't help you if the resource is so cheap that you
can afford to run at 10% utilization all the time.

High-end router vendors still support RSVP (the resource reservation
protocol) and differentiated services for enterprise customers who
require them, and I expect in cable ISP networks supporting voice they
probably do get some internal use.  But we've all been Zooming for the
past two years and nobody's home wireless router supports them; we've
been streaming Netflix for more than a decade.  it's much easier and
cheaper for the endpoint software to adapt to the available bandwidth
than to set up DiffServ (never mind RSVP) at every customer router in
the world.

-GAWollman

[1] There is a well-known result in queueing theory that summarizes
like this: if you have a serialized resource of fixed capacity and a
queue in front of it, and if arrivals are random and independent, then
the length of the queue will grow without bound if the mean arrival
rate of requests exceeds about 85% of the capacity of the resource.
Of course real routers don't have infinite queues, they drop traffic,
but the latency can still be enough to wreck isochronous streams like
voice.
-- 
Garrett A. Wollman    | "Act to avoid constraining the future; if you can,
wollman@bimajority.org| act to remove constraint from the future.  This is
Opinions not shared by| a thing you can do, are able to do, to do together."
my employers.         | - Graydon Saunders, _A Succession of Bad Days_ (2015)

[toc] | [prev] | [next] | [standalone]

#12964

On 5/19/2022 9:05, Bill Horne wrote:
> I was talking to an old friend yesterday, and he told me that he's
> been working from home for a while now, and the conversation turned to
> ISDN phone service, which I recommend to anyone who can still obtain
> it.
>
> 1. Which states still have tariffs for ISDN BRI lines?

I'm not entirely sure how to read this list, but AT&T keeps updating it. 
  It seems they have a strong push to de-regulate and remove tariffs 
from as many regions as possible.  It's been explained to me that some 
of these listings are "legacy" services, possible ISDN service.

http://cpr.att.com/pdf/dsa/zero_demand_tracker.pdf

[toc] | [prev] | [standalone]

Back to top | Article view | comp.dcom.telecom

csiph-web