Discussion:
[asterisk-users] ISDN
Wilton Helm
2008-10-13 20:44:26 UTC
Permalink
Hi,

I'm in the process of setting up Asterisk in a SOHO environment using ISDN for trunking. More specifically a BRI 2B+D circuit where one SPID is used for the business and the other is used for personal. The circuit already exists, but is presently being interfaced to POTS phones via a TA.

This configuration is not very common in the US, but we are fortunate that our LEC offers it price competitively with equivalent POTS services and it makes more sense, both in terms of voice quality (4 wire digital to the PABX) and flexibility.

Ideally it would allow any combination of two calls, identified by SPID.

If anyone has done anything similar, or has any experience with BRI ISDN, I would appreciate input and direction.

If anyone knows where documentation exists on configuring ISDN, that information would also be greatly appreciated. Asterisk has a bit of a learning curve, and ISDN BRI isn't the most widely used or covered aspect of it. BTW, I have a strong telecom background, so the theory part of it will not be a problem, only the necessary documentation to apply it to Asterisk.

Thanks,
Wilton Helm
Embedded System Resources
Michael Graves
2008-10-13 20:57:51 UTC
Permalink
I had considered something like this as well, but was convinced to go
another direction.

I wrote something up about it at the time.

http://www.smallnetbuilder.com/content/view/30444/84/

Michael



--Original Message Text---
From: Wilton Helm
Date: Mon, 13 Oct 2008 14:44:26 -0600

Hi,

I'm in the process of setting up Asterisk in a SOHO environment using
ISDN for trunking. More specifically a BRI 2B+D circuit where one SPID
is used for the business and the other is used for personal. The
circuit already exists, but is presently being interfaced to POTS
phones via a TA.

This configuration is not very common in the US, but we are fortunate
that our LEC offers it price competitively with equivalent POTS
services and it makes more sense, both in terms of voice quality (4
wire digital to the PABX) and flexibility.

Ideally it would allow any combination of two calls, identified by
SPID.

If anyone has done anything similar, or has any experience with BRI
ISDN, I would appreciate input and direction.

If anyone knows where documentation exists on configuring ISDN, that
information would also be greatly appreciated. Asterisk has a bit of a
learning curve, and ISDN BRI isn't the most widely used or covered
aspect of it. BTW, I have a strong telecom background, so the theory
part of it will not be a problem, only the necessary documentation to
apply it to Asterisk.

Thanks,
Wilton Helm
Embedded System Resources



--
Michael Graves
mgraves<at>mstvp.com
http://blog.mgraves.org
o713-861-4005
c713-201-1262
sip:***@pixelpower.onsip.com
skype mjgraves
fwd 54245
Steve Totaro
2008-10-13 21:37:37 UTC
Permalink
I have done this. Why BRIs exist in the US is beyond me. If you can, don't
go with BRI.

Who is the carrier. There is someone on the list that will tell you it is
impossible unless you use his code, which is not true.

Thanks,
Steve Totaro
Post by Michael Graves
I had considered something like this as well, but was convinced to go
another direction.
I wrote something up about it at the time.
http://www.smallnetbuilder.com/content/view/30444/84/
Michael
--Original Message Text---
*From:* Wilton Helm
*Date:* Mon, 13 Oct 2008 14:44:26 -0600
Hi,
I'm in the process of setting up Asterisk in a SOHO environment using ISDN
for trunking. More specifically a BRI 2B+D circuit where one SPID is used
for the business and the other is used for personal. The circuit already
exists, but is presently being interfaced to POTS phones via a TA.
This configuration is not very common in the US, but we are fortunate that
our LEC offers it price competitively with equivalent POTS services and it
makes more sense, both in terms of voice quality (4 wire digital to the
PABX) and flexibility.
Ideally it would allow any combination of two calls, identified by SPID.
If anyone has done anything similar, or has any experience with BRI ISDN, I
would appreciate input and direction.
If anyone knows where documentation exists on configuring ISDN, that
information would also be greatly appreciated. Asterisk has a bit of a
learning curve, and ISDN BRI isn't the most widely used or covered aspect of
it. BTW, I have a strong telecom background, so the theory part of it will
not be a problem, only the necessary documentation to apply it to Asterisk.
Thanks,
Wilton Helm
Embedded System Resources
--
Michael Graves
mgraves<at>mstvp.com
http://blog.mgraves.org
o713-861-4005
c713-201-1262
skype mjgraves
fwd 54245
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+12024369784 (Skype)
Hans Witvliet
2008-10-13 21:53:33 UTC
Permalink
Post by Steve Totaro
I have done this. Why BRIs exist in the US is beyond me.
Much of the idea's behind ISDN are hopelesly outdated, except for one:
With POTS, the analogue/Digital conversion is done some miles away, in
the your local number exchange, and the distance between your phone and
the exchange dictate the quality you can get.

With ISDN, the conversion is done in your phone, no further deteriation.
Some telco's offer a single, high bandwith channel, others dropped the
second B-channel (thus offering at reduced price 1B+D)


You wrote: "If you can, don't go with BRI."
I would agree, IF you can get a PRI-line for the same price.

Some time ago, i heard that BT offered PRI-lines with a reduced number
of B-channels. That would be a better alternative for BRI.

hw
Tzafrir Cohen
2008-10-14 09:49:31 UTC
Permalink
Post by Steve Totaro
I have done this. Why BRIs exist in the US is beyond me.
BRI is actually ISDN BRI. PRI is ISDN PRI. Uses very much the same
concepts, standards, etc. BRI is supported in chan_zap/chan_dahdi
through libpri :-)

In most parts of the world BRI adds some extra layers of complication to
make the CPE units behave a bit more like analog phones (PtMP). In the
US, AFAIK, this is not used.

Again I'll note that I have met very few cases, so I might be wrong.
--
Tzafrir Cohen
icq#16849755 jabber:***@xorcom.com
+972-50-7952406 mailto:***@xorcom.com
http://www.xorcom.com iax:***@local.xorcom.com/tzafrir
Gordon Henderson
2008-10-14 11:54:52 UTC
Permalink
Post by Steve Totaro
I have done this. Why BRIs exist in the US is beyond me. If you can,
don't go with BRI.
Why didn't BRI catch-on in the US? It's been in-use in the UK and Europe
for a long time (especially Germany AIUI). I have several sites with
ISDN2e (BRI) in the UK. In some locations it was cheaper to run in more
ISDN2e lines than get BT to provide an ISDN30e (BT 'forcing' the customer
to pay for the fibre, but they'd happily run ISDN2e over copper). One site
has 8 ISDN2e ports (16 channels), although I think only 6 are "lit" right
now.

I use mISDN FWIW.

Gordon
Wilton Helm
2008-10-14 16:53:20 UTC
Permalink
Post by Gordon Henderson
Why didn't BRI catch-on in the US?
I a word--greed. It arrived shortly after divestiture when there was a lot of competition in the market and a dozen independent regional telcos. Apparently they saw a huge cash cow for this data service and yet another competitive advantage to proprietary implementation details. I used to live in GTE territory (now Verizon) and they were charging 2 cents per minute of connect time! This was on top of monthly fees that were unreasonable to begin with. I don't know if they have all caught on now and fixed it, but its too late now because most of the US has DSL which is 10x the data rate and supports VoIP for voice.

I'm fortunate here that Qwest has offered it for at least 10 years at rates comparable to two POTS lines and no per minute charges. When I started using it, in my situation I got more features for less money than two POTS lines, which I would have needed instead.

The irony is that the direct cost (equipment) of ISDN is less per B channel than POTS. Anyone who has ever compared the cost of digital versus analog station cards for a PABX, knows painfully the cost of supporting A/D conversion, 90 V 20 Hz ringing and even DTMF registers. If they had wanted to the telcos could have made ISDN cheaper than POTS, still made money and moved technology forward in the process.

But to illustrate the mentality, GTE, who I mentioned above was serving the affluent community I was in with stepper switches in the CO until well into the 1980s! They put tone to pulse converters in front of them (initially for an extra fee) so they could support DTMF. Ironically they only put 600 ms interdigit time in the converters and the steppers could take up to 800 ms to find a link for the next digit, so the call failure rate ran 10 - 50%! I ran a PABX at the time and we did our own tone to pulse conversion just to avoid that. With 800 ms interdigit time we had at least 99% completion!

Wilton
Michael Graves
2008-10-13 21:55:01 UTC
Permalink
I had converations with both Pika and Xorcom wherein the thought that
it should be possible using their interface hardware. There might be
some software changes to be made in their drivers, but BRI should be
usable in the US.

I abandoned the idea for being more expensive when all costs are
considered.

Michael

--Original Message Text---
From: Steve Totaro
Date: Mon, 13 Oct 2008 17:37:37 -0400

I have done this. Why BRIs exist in the US is beyond me. If you can,
don't go with BRI.

Who is the carrier. There is someone on the list that will tell you it
is impossible unless you use his code, which is not true.

Thanks,
Steve Totaro

On Mon, Oct 13, 2008 at 4:57 PM, Michael Graves <***@mstvp.com>
wrote:
I had considered something like this as well, but was convinced to go
another direction.

I wrote something up about it at the time.

http://www.smallnetbuilder.com/content/view/30444/84/

Michael



--Original Message Text---
From: Wilton Helm
Date: Mon, 13 Oct 2008 14:44:26 -0600


Hi,

I'm in the process of setting up Asterisk in a SOHO environment using
ISDN for trunking. More specifically a BRI 2B+D circuit where one SPID
is used for the business and the other is used for personal. The
circuit already exists, but is presently being interfaced to POTS
phones via a TA.

This configuration is not very common in the US, but we are fortunate
that our LEC offers it price competitively with equivalent POTS
services and it makes more sense, both in terms of voice quality (4
wire digital to the PABX) and flexibility.

Ideally it would allow any combination of two calls, identified by
SPID.

If anyone has done anything similar, or has any experience with BRI
ISDN, I would appreciate input and direction.

If anyone knows where documentation exists on configuring ISDN, that
information would also be greatly appreciated. Asterisk has a bit of a
learning curve, and ISDN BRI isn't the most widely used or covered
aspect of it. BTW, I have a strong telecom background, so the theory
part of it will not be a problem, only the necessary documentation to
apply it to Asterisk.

Thanks,
Wilton Helm
Embedded System Resources





--
Michael Graves
mgraves<at>mstvp.com
http://blog.mgraves.org
o713-861-4005
c713-201-1262
sip:***@pixelpower.onsip.com
skype mjgraves
fwd 54245


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--
Michael Graves
mgraves<at>mstvp.com
http://blog.mgraves.org
o713-861-4005
c713-201-1262
sip:***@pixelpower.onsip.com
skype mjgraves
fwd 54245
Steve Totaro
2008-10-13 22:39:07 UTC
Permalink
The documentation is in my head, two solid days worth.

The issue is the SPID code that Marcin Pyco claimed he had the only code,
and way to make it work in the US..

You may need this "code" if you are using SPIDs to route calls. In my
situation, they were just a hunt group, two BRIs, and I was tasked with
adding a quad port Sangoma analog card. Absolutely NO difference in audio,
but talk about a mish mash of equipment. Luckily Sangoma drivers for
Zaptel 1.4 do not require Zaptel to be patched.

It absolutely refused to work with 1.2 so it became my first 1.4
installation out of necessity, I am sure 1.2 didn't work because of
conflicting patches (BRIStuff and Sangoma)

That is why Xorcom was so happy to help me with a US BRI, and I just thought
Tzafrir was a nice guy trying to help out...

Marcin Pyco claimed that BRI would not work without his code in the US and
went so far as to call me a liar.

I proved him wrong, but he is not very good at admitting he is wrong, he
blamed Verizon rather than apologizing. He is very good at calling people
liars but not so good at apologizing and admitting he is wrong.

Whatever the rub, using BRIStuff, Zaptel 1.4.X and a Junghanns' card or
knock-off (and even Sangoma drivers), it will work with Verizon.

I have pages upon pages of all the emails and IRC chats where I am called a
liar, and where Tzafrir admits his true motives (to his credit).

And finally the revelation that you do not need any additional code for
SPIDs (at least with Verizon) in the US, and around here everyone resells
Verizon anyways.

One thing to note is that inbound calls work immediately when the spans come
up BUT it takes ten to fifteen minutes for outbound calls to work.

I am not sure if the time starts at loading qozap or Asterisk but it works
beyond a shadow of a doubt, so don't pay for "code" that makes it work.

I am convinced that the conversations you had with Xorcom and probably Pika
(since Marcin works or worked there (LinkedIN)) came as a direct result of
my work.

Anyways, in this area, everything is close to a CO and I BET that calling
from a regular phone, you could never guess which is ISDN and which is POTS,
unless you cheat somehow, but not by voice quality. I am not sure why OP
thinks that two pair for voice is better than two unless he is afraid of
echo, which was absolutely no issue with the Sangoma cards with onboard EC.
--
Thanks,
Steve Totaro
+18887771888 (Toll Free)
+12409381212 (Cell)
+12024369784 (Skype)
I had converations with both Pika and Xorcom wherein the thought that it
should be possible using their interface hardware. There might be some
software changes to be made in their drivers, but BRI should be usable in
the US.
I abandoned the idea for being more expensive when all costs are
considered.
Michael
--Original Message Text---
*From:* Steve Totaro
*Date:* Mon, 13 Oct 2008 17:37:37 -0400
I have done this. Why BRIs exist in the US is beyond me. If you can, don't
go with BRI.
Who is the carrier. There is someone on the list that will tell you it is
impossible unless you use his code, which is not true.
Thanks,
Steve Totaro
I had considered something like this as well, but was convinced to go
another direction.
I wrote something up about it at the time.
*http://www.smallnetbuilder.com/content/view/30444/84/*
Michael
--Original Message Text---
*From:* Wilton Helm
*Date:* Mon, 13 Oct 2008 14:44:26 -0600
Hi,
I'm in the process of setting up Asterisk in a SOHO environment using ISDN
for trunking. More specifically a BRI 2B+D circuit where one SPID is used
for the business and the other is used for personal. The circuit already
exists, but is presently being interfaced to POTS phones via a TA.
This configuration is not very common in the US, but we are fortunate that
our LEC offers it price competitively with equivalent POTS services and it
makes more sense, both in terms of voice quality (4 wire digital to the
PABX) and flexibility.
Ideally it would allow any combination of two calls, identified by SPID.
If anyone has done anything similar, or has any experience with BRI ISDN, I
would appreciate input and direction.
If anyone knows where documentation exists on configuring ISDN, that
information would also be greatly appreciated. Asterisk has a bit of a
learning curve, and ISDN BRI isn't the most widely used or covered aspect of
it. BTW, I have a strong telecom background, so the theory part of it will
not be a problem, only the necessary documentation to apply it to Asterisk.
Thanks,
Wilton Helm
Embedded System Resources
--
Michael Graves
mgraves<at>*mstvp.com*
*http://blog.mgraves.org*
o713-861-4005
c713-201-1262
skype mjgraves
fwd 54245
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Thanks,
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+18887771888 (Toll Free)
+12409381212 (Cell)
+12024369784 (Skype)
--
Michael Graves
mgraves<at>mstvp.com
http://blog.mgraves.org
o713-861-4005
c713-201-1262
skype mjgraves
fwd 54245
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Tzafrir Cohen
2008-10-13 23:52:09 UTC
Permalink
Post by Michael Graves
I had converations with both Pika and Xorcom wherein the thought that
it should be possible using their interface hardware. There might be
some software changes to be made in their drivers, but BRI should be
usable in the US.
Or actually: I suppose that now that Asterisk finally knows that spans
can be of size 2B+1D (as of 1.4.22), chan_dahdi will support US BRI will
with any BRI device that has a Zaptel/DAHDI driver. That should be
either ours (Xorcom) BRI module of the Astribank, Junghanns
quad/octo/duo BRI cards and compatible, or the simple HFC-S -based
single port PCI cards. Sangoma A500 cards should have Zaptel drivers as
well.

However this is based on quite a few cases and mostly remains to be
tested.

(The relevant patch to Asterisk is trivial to apply to earlier versions
of 1.4 / 1.2)
--
Tzafrir Cohen
icq#16849755 jabber:***@xorcom.com
+972-50-7952406 mailto:***@xorcom.com
http://www.xorcom.com iax:***@local.xorcom.com/tzafrir
Wilton Helm
2008-10-14 03:44:30 UTC
Permalink
The card I have has no name but is based on the Winbond W6692CF chip and ships with RVS, which I think is for Windows and of no use to me. I'm not sure about whether it is supported by DAHDI or not.

Wilton
Tzafrir Cohen
2008-10-14 09:36:30 UTC
Permalink
Post by Wilton Helm
The card I have has no name but is based on the Winbond W6692CF
chip and ships with RVS, which I think is for Windows and of no
use to me. I'm not sure about whether it is supported by DAHDI or not.
There's a HFC-S winbond card. How does that card show on lspci?

I started adapting the driver of zaphfc ot dahdi. And got to the point
that I have a compiling but oopsing driver due to the fact that I don't
have such a card myself.
--
Tzafrir Cohen
icq#16849755 jabber:***@xorcom.com
+972-50-7952406 mailto:***@xorcom.com
http://www.xorcom.com iax:***@local.xorcom.com/tzafrir
Wilton Helm
2008-10-14 20:03:10 UTC
Permalink
Post by Tzafrir Cohen
There's a HFC-S winbond card. How does that card show on lspci?
Network controller: Dynalink IS64PH [0675:1702] ISDN Adapter
kernel modules: hisax

Does that tell you anything useful? Do you want more details? Would you
like to borrow one for a while (I have two)?

Wilton
Steve Totaro
2008-10-14 20:59:48 UTC
Permalink
Post by Tzafrir Cohen
Post by Michael Graves
I had converations with both Pika and Xorcom wherein the thought that
it should be possible using their interface hardware. There might be
some software changes to be made in their drivers, but BRI should be
usable in the US.
Or actually: I suppose that now that Asterisk finally knows that spans
can be of size 2B+1D (as of 1.4.22), chan_dahdi will support US BRI will
with any BRI device that has a Zaptel/DAHDI driver. That should be
either ours (Xorcom) BRI module of the Astribank, Junghanns
quad/octo/duo BRI cards and compatible, or the simple HFC-S -based
single port PCI cards. Sangoma A500 cards should have Zaptel drivers as
well.
However this is based on quite a few cases and mostly remains to be
tested.
(The relevant patch to Asterisk is trivial to apply to earlier versions
of 1.4 / 1.2)
Can you define the SPIDs and what to do with them, otherwise it is fairly
useless.
--
Thanks,
Steve Totaro
+18887771888 (Toll Free)
+12409381212 (Cell)
+12024369784 (Skype)
Steve Totaro
2008-10-14 21:05:25 UTC
Permalink
On Tue, Oct 14, 2008 at 4:59 PM, Steve Totaro <
Post by Steve Totaro
Post by Tzafrir Cohen
Post by Michael Graves
I had converations with both Pika and Xorcom wherein the thought that
it should be possible using their interface hardware. There might be
some software changes to be made in their drivers, but BRI should be
usable in the US.
Or actually: I suppose that now that Asterisk finally knows that spans
can be of size 2B+1D (as of 1.4.22), chan_dahdi will support US BRI will
with any BRI device that has a Zaptel/DAHDI driver. That should be
either ours (Xorcom) BRI module of the Astribank, Junghanns
quad/octo/duo BRI cards and compatible, or the simple HFC-S -based
single port PCI cards. Sangoma A500 cards should have Zaptel drivers as
well.
However this is based on quite a few cases and mostly remains to be
tested.
(The relevant patch to Asterisk is trivial to apply to earlier versions
of 1.4 / 1.2)
Can you define the SPIDs and what to do with them, otherwise it is fairly
useless.
--
Thanks,
Steve Totaro
+18887771888 (Toll Free)
+12409381212 (Cell)
+12024369784 (Skype)
In addition, do the BRI cards/drivers use the US Standards for BRI or the
R.O.W (fest of the world)?

http://www.smallnetbuilder.com/content/view/30444/84/
Written by Michael Graves, May 20th 2008
--
Thanks,
Steve Totaro
+18887771888 (Toll Free)
+12409381212 (Cell)
+12024369784 (Skype)
Joe Greco
2008-10-13 22:37:43 UTC
Permalink
I'm in the process of setting up Asterisk in a SOHO environment using =
ISDN for trunking. More specifically a BRI 2B+D circuit where one SPID =
is used for the business and the other is used for personal. The =
circuit already exists, but is presently being interfaced to POTS phones =
via a TA.
This configuration is not very common in the US, but we are fortunate =
that our LEC offers it price competitively with equivalent POTS services =
and it makes more sense, both in terms of voice quality (4 wire digital =
to the PABX) and flexibility.
Ideally it would allow any combination of two calls, identified by SPID.
If anyone has done anything similar, or has any experience with BRI =
ISDN, I would appreciate input and direction.
If anyone knows where documentation exists on configuring ISDN, that =
information would also be greatly appreciated. Asterisk has a bit of a =
learning curve, and ISDN BRI isn't the most widely used or covered =
aspect of it. BTW, I have a strong telecom background, so the theory =
part of it will not be a problem, only the necessary documentation to =
apply it to Asterisk.
The one solution I've heard, on and off again, that works with Asterisk
here in the US is the Eicon Diva cards.

There are other solutions. Where I am, we're unreasonably close to a
local radio conglomerate that has a number of high power antennas. We
found early on that RF interference was a killer, which caused me to run
a lot of our telecom and data wiring in conduit.

Unfortunately, we discovered that POTS lines were a hell of a mess when
connected to anything more complex than a phone or two. Lots of RF
interference. Church radio music on Sundays, even. So, we brought our
lines in on BRI, which we've used for data and voice elsewhere.

Being eternally frustrated with the lack of ISDN support after maybe 2000
here in the US (we have a bunch of interesting ISDN gear from the 90's!),
I set out to see what I could do to interface BRI to Asterisk. I *didn't*
go the Eicon route, because at the time it was considered relatively
unreliable.

Instead, we picked up an Adtran Atlas 550, which can handle ISDN BRI, PRI,
POTS, etc. We have been using the Atlas as a translator to convert BRI
to T1, which works moderately well, but we've seen some issues, mostly in
the capabilities of the Adtran (such as an inability to select the desired
SPID/DN for outgoing calls).

The Adtran has some other amazing capabilities, such as providing FXO/FXS
ports, and even ISDN BRI ports for other devices we'd liked hooked into
our PBX.

Despite that, I'd love to see an ISDN BRI solution for the US. I might
be willing to test the Eicon Diva Server card... hm.

... JG
--
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.
Wilton Helm
2008-10-14 03:15:17 UTC
Permalink
Post by Steve Totaro
I have done this.
Good
Post by Steve Totaro
Why BRIs exist in the US is beyond me.
I'm not sure why you say that. It is the only way I know of two get two digital voice grade circuits at prices competitive with POTS. The better question is why the LECs used such poor judgment when they introduced this. Most were charging outrageous prices that had no technical justification and per minute usage fees. They destroyed the market before it got off the ground. I don't use it for data any more now that I have DSL, but it is still a very viable voice channel.

If you can, don't go with BRI.
Why? (Not that I don't already have it and have been using it for seven years.)

Who is the carrier.
Qwest (formerly US West or US Worst as some used to call it).

So do you have some information about what you did or where to get configuration information?

Wilton
Wilton Helm
2008-10-14 03:39:30 UTC
Permalink
Post by Hans Witvliet
With ISDN, the conversion is done in your phone
Exactly. Or in the case of Asterisk, it is a 4 wire digital right into the switch--no degradation. Even converting back and forth between analog and digital multiple times compromises quality. Try doing a dial-up modem across such a path. The best you will get is 20 - 30 K.
Post by Hans Witvliet
IF you can get a PRI-line for the same price.
Not to mention that the interfaces for PRI are about five times as expensive. I'm not sure why. It doesn't seem like it ought to take a lot of electronics to break down the bit stream.
Joe Greco
2008-10-14 13:17:29 UTC
Permalink
Post by Hans Witvliet
With ISDN, the conversion is done in your phone
Exactly. Or in the case of Asterisk, it is a 4 wire digital right into =
the switch--no degradation. Even converting back and forth between =
analog and digital multiple times compromises quality. Try doing a =
dial-up modem across such a path. The best you will get is 20 - 30 K.
A single D/A hop destroys the ability to do 56k. Successful 56k requires
that there be a single A/D hop at the far end (the user's POTS interface)
and then digital delivery of signal the remainder of the way to the
terminating equipment. (modem -> phone co A/D -> digital to ISP modem
bank).

If you stick an extra D/A (maybe plus A/D) transformation in there, you
will probably get fairly clean speeds in the upper ranges of 28.8-33.6,
but that'll be it (modem -> phone co A/D -> digital network -> phone co
D/A -> your buddy's modem). If you're unlucky enough to get some crummy
phone co arrangement where they punt you back and forth from digital to
analog and back to digital within their network, that's even worse.
Joe Greco
2008-10-14 14:31:53 UTC
Permalink
Post by Gordon Henderson
Post by Steve Totaro
I have done this. Why BRIs exist in the US is beyond me. If you can,
don't go with BRI.
Why didn't BRI catch-on in the US?
Stupidity.

Okay, well, many reasons.

It was targetted as a business service, and the pricing models (at least
locally) didn't offer a reasonable residential offering until ... I'm
thinking almost the mid 1990's (1994-1995). That's when I first recall
hearing about the availability of residential BRI that didn't charge by
the minute, I think.

The telcos had this huge amount of legacy plant installed, much of which
wasn't particularly great copper. Good enough for voice. There was also
lots of CO and remote equipment for which BRI simply wasn't available. I
fondly remember Ameritech running BRI lines out of MILWWI10, using a bunch
of repeaters, because they didn't have the capabilities (or capacity, can't
recall for sure) at MILWWI45,

(you know what's interesting, Google Maps knows CLLI codes!)

which resulted in about 11 extra miles on a BRI circuit, and I guess it was
much worse in wire miles. It's useful to remember that the phone company
expects their equipment to be good for decades, and so there's a huge
amount of resistance to upgrading "just for newfangled data services."

Now, I know that there was this huge "vision" in the '60's and '70's of the
possibility of things like videophones, and ISDN might well have been the
ideal platform for delivering something like that, but the flip side is
that the Carterfone decision resulted in a booming non-Ma-Bell CPE business
and Ma Bell mostly realizing that they were getting shut out of that market.

Now, prior to that point, you had a situation where it was Only The Phone
Guy who would bring CPE to your house and hook it up, you might dare to
move the phone line or jack, but usually not. This meant that a service
that was more complex to provision would still be relatively easy for Ma
Bell to deploy, since it was just training and equipping their techs that
was important. The end user would have had no idea what the underlying
technology was.

After that point, though, it would have been really hard to sell a
residential BRI, unless you had equipment capable of automatic
configuration, because it's hard enough for Joe Sixpack to plug in a
POTS line correctly as it is. Configuring more-complex stuff, especially
in the days before nifty little GUI interfaces (which requires electronic
capabilities not really present until recent years) would have been rough.

Despite all this, there was a renaissance with BRI in the 1990's. We had
reached a point where the electronics were reasonable. The Internet did
not yet exist for most people, and modem technology was 9600 or 14.4. As
corporate networking and the Internet exploded, there was a willingness to
pay premium prices for ISDN gear that would allow relatively inexpensive
BRI circuits to attach at speeds far beyond POTS.

Then we saw that fall apart, as speeds increased to 28.8 and then 56K,
and for most users, that was close enough. DSL was right on the heels of
that, offering greater-than-ISDN speeds. ISDN BRI was back to dead status
by about 2000. You can *see* this in terms of CPE devices that supported
ISDN BRI.

In the meantime, the ILEC's began to truly understand the difference
between switched circuit and packet data services. Many people had been
using ISDN BRI as a faster and more flexible alternative to 56K DDS
lines, which tended to tie up switch capacity. More people were ordering
"second lines," and leaving them connected to local ISP's for hours at a
time, which created trunk, network, and switch capacity challenges for
the ILEC's. This was devastating to the ILEC's, which typically plan
capital expenditures to be good for many years, but in this case, I have
to assume that the ILEC planners knew that Internet would be provided
over circuits other than their switched POTS/DS0's in the near future,
which would dump capacity requirements back down. They even got smacked
harder than maybe they expected, as some people gave up land lines
entirely, in favor of cell...

In the meantime, many of the major "data" uses that had been envisioned
for ISDN BRI have been done, better, cheaper, on the Internet.
Videophone? Easy on a PC with speakers, mic, and an Internet connection,
but hopelessly challenging to someone with a POTS or BRI line. Private
network interconnection? VPN over Internet. Etc.

This has meant that BRI has "evolved" towards a way to deliver telephone
network with no loss, or, rather, most of the envisioned benefits are no
longer likely to be exploited via BRI. So you don't see many BRI lines,
and it is pretty common for those that you do see to be hooked up to a
PBX, automated call handling system, etc.

Further, telco departments to handle BRI's have suffered mightily. We had
a problem maybe a year ago where we had suddenly "broken" and were unable
to dial... local? ld? I can't remember, but we were getting an operator
intercept for one of them. A dozen phone calls later, and ten people who
were various degrees of "sure" they knew where to refer me to, I still had
not succeeded in finding the correct department to talk to. Ironically,
it appears that the complaint I submitted through the automatic system
MIGHT have been responsible for getting the problem resolved. Even in
1998, which was probably the height of the ISDN BRI here in the US, an
installer who was installing lines noted that you could count the number
of BRI-qualified installers in the county on a hand, and they were
generally hicap people who simply got the BRI jobs when one came along.

In any case, this is by no means a comprehensive history or analysis of
the situation, but just a description of a variety of factors that have
worked against BRI.

... JG
--
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.
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