Re: Extending network over a dry pair

[Matthew Crocker <matthew () corp crocker com>]

You can’t push a T1 through a load-coil which are normally placed every mile on copper.   Typically the telco would cut 
the load-coil out of the 2 T1 pairs and install a repeater to push the T1 the next mile.  That is with a traditional T1 
circuit.   Most T1s these days are 2 wire HDSL which has a max of about 12k feet.  So for 6 miles you’ll need 3 
repeaters in the span *if* you have good copper.



From: NANOG <nanog-bounces () nanog org> on behalf of Nick Bogle <nick () bogle se>
Date: Wednesday, December 12, 2018 at 10:00 PM
To: Dan Hollis <goemon () sasami anime net>
Cc: "nanog () nanog org" <nanog () nanog org>
Subject: Re: Extending network over a dry pair

The driving distance is 4 miles, we are leasing it from CenturyLink whose headend maybe adds a mile or less, it's on 
the route and about half way through. I made it 6 miles to be safe. We currently can pull a full 1.5Mbps off of that T1 
we run there so perhaps CenturyLink is repeating at their CO and/or along the route?


On Wed, Dec 12, 2018 at 6:32 PM Dan Hollis <goemon () sasami anime net<mailto:goemon () sasami anime net>> wrote:
I doubt he will get >1.5mbps with those over a 6 mile long connection.

I did a quick check and flowpoint 2200s seem to max out at 192kbps at 3
miles.

-Dan

On Wed, 12 Dec 2018, Tim Pozar wrote:

> For dry pairs, I have used Flowpoint SDSL modems (see attached).  I
> picked these up for a sawbuck.
>
> Tim
>
> On 12/12/18 5:00 PM, Dan Hollis wrote:
> > On Wed, 12 Dec 2018, Nick Bogle wrote:
> > > A quick question for you guys;
> > >
> > > If you had a single dry pair (pair of copper wires originally for phones)
> > > to a remote site that was around 6 miles away, what would you use? We
> > > currently are just extending a T1 line to this site, but 1.5Mbps isn't
> > > cutting it anymore. Unfortunately it's a research site on a federally
> > > protected wildlife preserve so we can't run any new infrastructure (fiber
> > > etc) and it isn't in a geographical place where point to point
> > > wireless is
> > > practical. We were thinking there is some sort of network extender that
> > > uses some form of DSL for higher bandwidth capacity.
> > >
> > > Any suggestions?
> >
> > If this is telco provided dry pair then the distance is probably longer
> > than 6 miles as the endpoints are probably tied together through a telco
> > CO.
> >
> > I have not heard of any equipment which will work over a 6 mile pair any
> > faster than you're getting with T1.
> >
> > You might consider setting up wireless repeaters to bridge where there
> > is no direct LOS. Look at what the hamwan guys have done.
> > http://hamwan.org/
> >
> > -Dan