Subject: (usr-tc) ISDN leased line on DSP?

From: Jeff Mcadams <[email-masked]>
Date: Wed, 20 Sep 2000 21:24:24 +0000

OK...this is a bizarre one..

I have a customer wanting to upgrade from 2 channel ISDN, to a 2 channel
leased line type of set up (don't ask, I'm not sure why).  In any case,
they have an ISDN PRI into their location to support their voice traffic
on their PBX.  What they want to do (and apparently have an Adtran unit
to do this on their end) is to pull two channels off the PRI and hand
them to a cisco 1600 as a nailed up data connection (ie, no dialing).  I
know that you can set up an ISDN leased line connection like this, but
I've never seen anyone pull two channels off a PRI to do this.  *shrug*

In any case...this setup is giving our mutual CLEC telephone company
fits on how to do this.  Being a leased line setup, my initial response
was to say, "OK, drop that to me on a frac-t1 connection to my cisco
3640 down there."  I *think* this can be made to work...the tech dude at
the telco (who's pretty sharp and friendly) thinks he can get this
delivered to my 3640 on a frac-t1...

Now...I like our telco down there a lot...they're good guys, so I want
to try to help them out if I can...and besides...I wanna do this setup
without doing alot of really weird provisioning, as that tends to cause
problems down the line.  So, my question boils down to...

Can a DSP be made to use two channels as an ISDN leased line connection?
My thinking being that if I could peel off two channels of one of my
PRIs, it might be easier, simpler, more reliable, etc. to take my two
channels and patch them through the switch to these folks two channels,
rather than having to add/drop mux it out somewhere, convert it to a
frac-t1, and proly several other weird gyrations, to get the connection
to me.  Not being a telco tech, I'm not sure if this would be easier to
do or not...I can't imagine it would make it harder, but who knows.  But
before I offered to the telco tech dude, I wanted to make sure the DSPs
would indeed do this.  The impression I've gotten from what I've looked
at so far, is that no, the DSPs *won't* do this...but I'd like to get
some confirmation from folks that know more about this than I.

Thanks!

P.S.  Still no response from anyone of any signficance about the news
server on totalservice.  :/
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

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From: Mark Thornton <[email-masked]>
Date: Wed, 20 Sep 2000 21:55:57 +0000

Are you sure the Adtran is set up to add/drop from a PRI? That would put a
lot of intelligence in the Adtran that is not normally included in a csu/dsu
in order to deal with the D channel call setup stuff. It is my understanding
that a PRI isn't really sliced up just like a CT1.

We provide the same functionality to a few of our clients using an Ascend
router configured in the 'nailed' mode. This essentially creates a leased
line between their router and the dsp, and has the advantage of moving to
other PRI's if one of them fails for any reason. We set up our end to never
dump that call for any sort of timeout.

Mark Thornton
San Marcos Internet, Inc.
512-393-5300

----- Original Message -----
From: "Jeff Mcadams" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, September 20, 2000 2:20 PM
Subject: (usr-tc) ISDN leased line on DSP?

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From: Paul Farber <[email-masked]>
Date: Wed, 20 Sep 2000 21:58:07 +0000

I tried this a while ago with BELL/Verizon.. I ordered an point to point
ISDN circuit.. it showed up as a plain old ISDN but with no useage
charges, I just paid by the mile.

But everything else was a plain old ISDN circuit... plugged it into a
courier I modem and let her rip.  So I guess your CLEC could reroute it to
a pair on you PRI if they can pull them out of the circuit and reassign
them to that dedicated link.

It might not be tarriffed to work that way, but if  they are willing to
try it...

Paul Farber
Farber Technology
[email-masked]
Ph  570-628-5303
Fax 570-628-5545

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From: Jeff Mcadams <[email-masked]>
Date: Wed, 20 Sep 2000 22:07:34 +0000

Also sprach Mark Thornton
>Are you sure the Adtran is set up to add/drop from a PRI? That would
>put a lot of intelligence in the Adtran that is not normally included
>in a csu/dsu in order to deal with the D channel call setup stuff. It
>is my understanding that a PRI isn't really sliced up just like a CT1.

Yeah...I looked at some of the Adtran stuff...it looks like they have
some rather intelligent "CSU/DSU's"...up to the point of doing IP
routing to some degree.  It looks like it can seriously slice and dice a
connection any way you want it...with some of their equipment, it looks
like it'll even drop a single DS0 out of a DS3 like this.

I've called the consultant dude working on this whole setup to try to
find out the actual Adtran unit that they're using, in the hopes that
it might tell me a bit more about the setup they're doing and how it
might affect us.

>We provide the same functionality to a few of our clients using an
>Ascend router configured in the 'nailed' mode. This essentially creates
>a leased line between their router and the dsp, and has the advantage
>of moving to other PRI's if one of them fails for any reason. We set up
>our end to never dump that call for any sort of timeout.

Ugh...don't get me started.  I suggested a channelized T1, to pull of
channels to do this...they already had the PRI in place.  I suggested
taking the PRI into the PBX and then provision a BRI out of the PBX to a
BRI router and do a nailed dial-up connection like you suggested.  They
already had the Cisco 1600 and didn't want to purchase the BRI card for
it, and already had the Adtran to break out the two PRI channels.

*cue rant about people ordering equipment and services before knowing if
it will work end-to-end or not*  *sigh*

Anyway...I'm not wanting to put a whole lot of work into this, since the
customer and consultant pretty much have their minds made up on how they
want to do this, and aren't willing to consider suggestions on better
ways to handle it, but I thought I'd ask to see if you could set aside
ISDN leased line channels on a DSP.  I know such a thing as an ISDN
leased line exists, and its not a dialed connection, but didn't know if
the DSPs supported it.
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

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From: Jeff Mcadams <[email-masked]>
Date: Wed, 20 Sep 2000 22:09:16 +0000

Also sprach Paul Farber
>I tried this a while ago with BELL/Verizon.. I ordered an point to
>point ISDN circuit.. it showed up as a plain old ISDN but with no
>useage charges, I just paid by the mile.

Right...and its not dialed, correct?  It just comes up and is connected
through as a clear connection.  Did you have to set up multi-link to be
able to have a 128kbps channel on that?  Or was it a clear 128kbps
channel?  That's one thing I wasn't sure on...I was assuming it'd
require MP, but hadn't ever actually experienced it, so didn't know for
sure.

>courier I modem and let her rip.  So I guess your CLEC could reroute it
>to a pair on you PRI if they can pull them out of the circuit and
>reassign them to that dedicated link.

Right...I thought it might be easier for the CLEC to do that...I'm not
sure if you can configure the DSP to do that though.

>It might not be tarriffed to work that way, but if  they are willing to

Oh...these are good people...they're willing to give just about anything
a try.  It helps that they seem to really like me and IgLou.  :)
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

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From: Charles Sprickman <[email-masked]>
Date: Wed, 20 Sep 2000 23:02:30 +0000

> leased line exists, and its not a dialed connection, but didn't know if

The only thing that comes to mind here is that this would only work if
your telco and their telco were the same entity...  Otherwise I can't
imagine this working.  I've never heard of any centrex-type service going
cross-carrier...

Just another possible data point.

Charles

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From: Paul Farber <[email-masked]>
Date: Wed, 20 Sep 2000 23:16:38 +0000

I *think* it came up as a MLPPP circuit.... there was really nothing to
it.. I got a spid and had to give the modem a different init string
(ignore carrier.. cant remember.. the circuit was taken down a few months
ago.)

Paul Farber
Farber Technology
[email-masked]
Ph  570-628-5303
Fax 570-628-5545

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From: Jeff Mcadams <[email-masked]>
Date: Wed, 20 Sep 2000 23:29:37 +0000

Also sprach Charles Sprickman
>imagine this working.  I've never heard of any centrex-type service
>going cross-carrier...

Yup, same telco...so no problems there.
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

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From: Jeff Mcadams <[email-masked]>
Date: Wed, 20 Sep 2000 23:59:32 +0000

Also sprach Paul Farber
>I *think* it came up as a MLPPP circuit.... 

OK...that's what I thought...I'm not aware of any support at the ISDN
level for making multiple channels into a bigger single pipe like there
is for fractional-T1's.

>there was really nothing to it.. I got a spid and had to give the modem
>a different init string (ignore carrier.. cant remember.. the circuit
>was taken down a few months ago.)

Probably ignore carrier and just to answer or originate without dialing
probably.  I didn't figure it was a big deal...thanks for the input
though.  :)
-- 
Jeff McAdams                            Email: [email-masked]
Head Network Administrator              Voice: (502) 966-3848
IgLou Internet Services                        (800) 436-4456

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