for keeping track of my digital experiments

Today started out with a woeful surprise. Snow!?!? Yeah I know I’ve lived here in Minnesota for almost five years now, and I’ve never seen snow this late in April. I hadn’t coded in awhile, not for about two weeks. Desayuné, me lavé los dientes y me puse mis ropas en el cuerpo. After that I started up my laptop.

I had recieved an email from Scott VanderVeer Thursday night, asking me about The Source. The Source is an early scripting job that I did for the youth group at Trinity Presbyterian Church that I was more actively a part of in the past. This was before I become a more regular attendee and member of Emmanuel Mennonite Church. The Source kind of died out about 5-6 months ago. Maybe Scott can give it the new blood it needs to take off again. So the first half of the day was spent interspersed between giving Scott assistance on the finer points of DNS issues and PHP scripting, interspersed with various household chores.

After lunch was spent working on a contract coding job for these guys that call themselves, “Tribal Shaman” and “Zerja Sone”. They are working this upstart cracking/hacking network called XSSLink and Prohacks.org. I got called in to write the backend PHP/MySQL data processing and arrange the hosting, as they have other tasks at hand. Something about affiliates and investment return. I would have to say that the XSSLink backend is my craziest undertaking to date. “Tribal Shaman” wanted a completely Plug ‘n Play tracking method in Javascript as well as a monetized linking system at minimal cost. So I will be attempting to load balance across a couple free hosts. It will be risky but worth the payout.

And now as I write this at almost half past 11pm I feel my body asking to sleep. Which then got me thinking about this interesting venture called, Rockabye Baby!. The go by the logo, “Transform your favorite rock music into baby music.” They Green Day riff on the front page certainly sounds calming. Just imagine a couple years down the road, “Daddy … why do you have a different version of my lullaby music on your computer?” Which could turn into a valuable teaching moment about the world in general and what the artists are getting at when they offer up their work to the world.

On this week’s show, Jason Zerbe learns about the technology behind DSL.

The topics for R&D are:

1. Do DSL soft modems exist and how do they work?
2. Is DSL soft modem the source code available?
3. Can an end-user create their own DSL links?

According to the Wikipedia article on DSL soft modems, the current lack of DSL soft modems is because of SOHO (small office/home office) networking. Hence the embedded DSL gateways take care of the modulation and networking. I’ve found out that speed of the DSL service is directly proportional to the modulation type. In order from least efficient modulation to most efficient: T1413, GDMT, GLITE, ADSL2, ADSL2Plus. Then there is also MMODE modulation (multi-mode) that automatically detects what type of modulation is being used. In my area (central Woodbury, Minnesota) QWest is using GDMT modulation that is auto detected by the MMODE setting on their DSL gateways. For a list of DSL modems supported by customer service, you can check out this page.

There are plenty of papers and articles about how DSL works (a 2001 Microsoft paper) and twice as much documentation and source code about analog soft modems. I could not find any source code that deals with building a DSL soft modem. I did find a 1999 precursor to “full DSL” done by Andreas Gustafsson. Too, bad guess we’re going to have to stick with those little embedded devices and wall-wart combos.

Yes, you can create your own DSL modem to DSL modem links, with the cooperation of the reigning TelCo (telephone company). To do so you must purchase a “dry copper” line, typically used for alarm systems, and have the TelCo route the dry line to another dry line. “Dry copper” is called such, because it carries no power or dial-tone, as opposed to “wet copper” or a line carrying dial-tone. At the termination of this other dry line, you have your buddy place a DSL modem on his end, and you place a DSL modem on your end. Presto, long-range LAN/WAN. For more information and ideas about this: check out the pbs.org article from Robert X. Cringely.

12/22/2007 – Add: I was poking around and I found a retailer of DSL modems and Ethernet extenders. I have been experiencing some trouble with the 100Mbps Ethernet link & Telephone combo that runs on the Cat5 that I installed last summer. It seems as though I might have exceeded the Ethernet spec’s distance.