NOTE (4/5/00): This page
was designed as a way for other isp's to save time in getting broadband
access to their customers. If something doesn't seem complete it's
because I assume a high level of technical expertise on the reader's part.
I was caught by the slashdot post after being out of town for a couple of
days. I'll fill in a few things near the bottom to help out the none
technical types reading (and talking) about this site. I really
REALLY recommend the Paradyne book noted at the bottom of this page.
It will help answer many other questions...
The SDSL Homebrew Home Page
Last updated 4/5/200 11:37pm (sigh)
This page is intended to describe in detail how I
put SDSL services into my home town without a CLEC (Local Telco) providing the majority of
the system. Please do not make this out to be any more than my accumulated knowledge
(such as it is) relating to my project. I've used some of what I learned, and some
of what I've learned over the last several months of researching this has been a complete
waste of time. Either way, I hope that this will save you some time and money!
Enough for the disclaimer...
I live an a VERY rural area
of eastern Washington. There are about 500 phone numbers in my local phone book
(judging by my bill I think that half of them must be mine!). Many of my customers
are out at extreme ranges and/or are on very old Telco equipment. All of the testing
that I've done shows that 56k v.90 will only work for a few of my customers thereby making
the hardware/phone line costs a complete waste of money.
I still wanted to be able
to offer my customers a high speed solution. Some of them are what I call power
users (home users who really should get a new life) and some are business customers.
Some of the business customers have offices in a number of the surrounding towns
and they will have to link them all together someday.
So, having looked into
wireless... My POP is at a very low point of town and it is right beside a rock
bluff. Wireless would also cover the downtown corridor very nicely but it would also
be limited in distance and would be much more expensive to get up and running.
Especially when you consider that I would probably have to put in a point-to-point system
to feed a multipoint-to-point system on top of one of the local grain elevators (If the
grain company would let me).
That left me with a dsl
solution. I called the Telco sales rep that services my area and we had a number of
long conversations (I'd have taken him to lunch if he wasn't so far away (I'll still do it
anyway when I can)). Tom at Century Tel was a great help. We were able to
determine that Century was going to roll out dsl services (in fact it should be out by
now) just not in Odessa any time soon. We also decided on what should work ok out
here. Which brings me to what you all want to know!!!
Tom put me in touch with
the local PairGain rep and arranged for me to borrow a pair of PairGain dsl modems for 1
month. (You need TWO modems to make this work without a DSLAM (that's basically a
pm3 for dsl lines)). Also, Howard at Net to Net Technologies offered to let me try
out a pair of his modems so that the two systems could be run side by side.
I then ordered two
circuits. One to my house and one to our local hospital (they are stuck paying
$1000.00 per month for a 348k connection that they need for video medicine and as a local
tax payer who voted for the M & O levy.....). I ordered 1 pair
of dry, unloaded, unconditioned, copper pair from my office to each location.
(About $20.00 per month.) I was also able
to talk to the installing tech (purely by chance due to Century Tel's practice of checking
with me before doing anything with my system (did I mention that Century Tel is a great
local company?)) and I asked that all of the bridge taps be removed also. (They were
going to do that anyway.)
It took about three weeks
for the circuits to be installed. Mostly the delay was due to the strangeness of
this order and the fact that I still had no modems at the due date.
After what seemed like
forever, I got the circuits and one set of modems all at the same place at the same time.
It was a Saturday when I picked up the Net To Net modems from my main office.
I found out that I needed an RJ45 connector to hook them up to the
dry pair (These are apparently called "Alarm Circuits"
some times). So I had one of my guys build me a standard phone cord with an RJ45 on
the red and green wires of the other end. I then raced the 40 miles (well under the
posted speed limit mind you <G>) back to Odessa. I then hooked
one modem (the SNE1000P) into the hub at my POP and the SNE1000S into the newly installed
hub at my house. I also hooked them up to the dry pair circuit using my custom RJ11
to RJ45 cables. And NOTHING happened! No link to the hubs,
no link to each other, nothing. Well s*%t.
Next I called Century Tel
out to retest the lines (I used my meter to check for continuity on the wires after tying
one end together). I must have not gotten the lines together right because the telco
tests showed all was very good. This time I got the test readings from them:
(distance (20,000 feet to me and 6300 feet to the hospital), ohms (about 800 and about
400), dB loss and whatever else they could/would give me). Everything checked out
good. Upon closer inspection I found that the wires going into one of my RJ11 to
RJ45 adapters didn't go all the way in. I then tried things with a new adapter and
shazam, the Net To Net modems saw each other! (Egg on face moment)
I still, however did not
see the modems on either end of the system. I called tech support (and got right
through I might add (way to go guys!)) and made the determination that you must use a
cross over cable to use them with a hub. I didn't have one so I'm just using the X
port on the two hubs. As a side note: I asked the tech why in the world they
would do such a ridiculous thing and he said that they were designed to be used on a
switch and that would require different cabling, does this sound right? The one nice
thing about this is that you won't have to use anything but a NIC card at the average SOHO
links were all up and running (which with the cabling done right was truly a plug and play
deal) all I had to do was set up the remote machine with a free IP address and I was off
and running. No username or anything as the remote system does not have to
authenticate onto my network for any reason (it only goes through the router).
The PairGain setup was
setup at the Odessa Memorial Hospital and was a similarly brain dead install.
I used hardware
from www.nettonettech.com (the sne1000p and the
sne1000s for my house) at a cost of about $700.00 for the PAIR of modems. And www.pairgain.com (the Megabit Modem 768+ and 768) at a
cost of about $1200.00 per PAIR. The Net To Net can be set to 4 speeds from 272k to
1.16mbps and the PairGain are a flat 768k. Seeing how I only have
a Frame Relay T-1 (CIR of 768k) to the whole town I don't see a need for the higher speed
and probably won't use it (unless I can talk some customers into using an off site backup
The final results:
The Net To Net modems
hooked up at 272k (I saw a maximum of about 30k/sec on Netscape) to my house at 20,000
feet and full speed at our local hospital at 6,300 feet. I saw an occasional outage
while they retained every once in a while (I saw this 3 or 4 times in the two weeks that I
had them at my house, never at the hospital). The PairGain Modems (actually HDSL not
SDSL) worked perfectly at 768k (I did a big download from the server and it was at
87k/sec! and still climbing when I stopped it, how's 14megs in under 3 minutes grab
ya!!!!) to both locations with no known outages (the Net To Net had more informative
Is the PairGain worth the
extra $500 or so? Don't know, the only time that I really noticed the extra speed
was with PC Anywhere. It's almost like I'm sitting right at the server. For
Web pages I couldn't tell much.
7/23/1999: Just for
kicks, I just downloaded a Radius log file from my server. It was 41,272,729bytes
(all text) and it took 2:55 minutes at 235,844 bytes/sec according to PC Anywhere's file
transfer stats! THAT is why DSL can be so over sold! Who can use that much
bandwidth for more than a few seconds at a time normally!
The Latest News:
January, 10 2000
some of the PairGain 300s's (about $900 per pair). These units are great! I got 2.1
meg at about 4000 feet and 1.2 meg at 20,000 feet! They cost about
the same as the Net to Net units but were much more stable and faster at
the long ranges. I got ftp downloads from my internet server of
240k/sec using the Internet Explorer download program. I bought a
pair of these! I'm actually hosting a web site on it to see how well
it works (www.craigsmithmotorsports.com).
No problems of any kind for the last month!!!
I am now also the proud owner of a
pair of Net to Net 2000SNE modems. They are about $900 per pair
also. They are running at 1.6 meg on the 20k' circuit to my
house. Actual speeds have been about the same as the PairGain 300s
and just as stable (good job both of you!).
I've got to
say that BOTH of these new products are much better than the first ones
that I tried. Neither one ever has to retrain. They have had
much better up time than my t-1!
I found the Paradyne source
book (it's free) a good read. Although you really don't need all of the info in it.
For those of you left with
questions at this point.... I am the ISP. The circuit must run
from your locations THROUGH the Telco office then to then to the
ISP. I do pay about $20/month for the circuit (just the circuit, not
the access (I already have lots of that ;-)), if your Telco is going to
charge more than that then the only reason to do so is to screw you out of
cheap service. They had these cheap circuits for years! The
only reason they are charging more for them now is cause someone found a
way to use them better than the Telco. Time to hit the phone and
call the PUC/UTC in your state. Don't whine about it to the rest of
use, we're in (or soon will be) the same boat. Call your
congressman..... As for this being illegal: If your the ISP you can
sell your bandwidth any way you want. If you're an end user then you
need to read your AUP/TOS, ours does not allow for resale of our
residential services. Much more help and expertise can be had by
signing up for the dsl list at www.isp-lists.com .
Be forwarned though, this is a professional list! Watch for a while
and search the archives BEFORE you ask any questions as you might not like
the answer if we JUST went over your topic.....
Have fun, this is easy (that's
why I can do it <VBG>) and it does work well.