Surf'n from Home

by Andrew W. Donoho - A work in progress
Copyright 1994 by Andrew W. Donoho, All Rights Reserved.

What's a long time net junkie to do... Your POSSLQ has discovered the internet and wants in on the action. Well, I jumped into my blue suit (no, not the pinstripes but the blue tights with red underware and the big "N" on the chest). I decided that I needed to bring my home office into the 1990's. Since we were moving into a new house and Southwestern Bell was offering an experimental ISDN tariff, I decided to wire it up for 10BaseT networking and ISDN.

It's not as easy as it looks. First, I discovered that "nobody knows nuttin' " when it comes to networking. Second, they know even less when it comes to mixed protocol and mixed media networks like I want to run (both IP and AppleTalk over ISDN, POTS, EtherNet and LocalTalk). Third, they want to run screaming away when they see my budget and all of the old creaking hardware that I want to work on this network (I mean, does anybody really use their old MacPortable). It's not totally hopeless -- just don't expect any help from anyone.

Rebooting my Life

Well, I've just come out of the long dark night that was Fusion Data Systems and am rebooting my career. One of my goals is a return to my youth to program from home. Well, to do that and retain the appropriate coolness factor, I needed a high speed internet connection. I've been a net junkie on and off since 1980 when a friend dropped out of MIT and introduced me to the prehistoric ARPAnet. Southwestern Bell's new ISDN tariff seemed to fit the bill. They were having a special on ISDN installation of just $90 versus the regular $585 and a flat monthly rate of $57.00. This is real hard to resist. While I want my company to be mostly just me (I've had enough of management), I do have several friends that I want to collaborate with. So, using ISDN and exploiting the promotional tariff, we are setting up a "Virtual" LAN.

Because I have ten years worth of old Mac hardware cluttering up my life, everyone in the house gets a machine -- even the kids. That's the problem specification: be cool, use ISDN for the "virtual" office, use my existing hardware and go fast.

Connecting the Dots

I created this network rather backwards to most people, I started with the wiring. When SWBell was installing our new phones, I had them install a punchdown block. This allows me to mix and match wall sockets to network topologies. Because you are going to change your mind, you must have the flexibility a punchdown block allows.

Another key factor is to get enough twisted pairs installed to each socket. Your voice sockets should have two pairs and your data sockets should have 4 pairs though you can get away with just two. The installer is going to want to use four pair cable to run voice and data. Don't let him! Your analog POTS service will suffer from being in the cable sheath with any highspeed data (yes, localtalk is highspeed data). Most telephone company installers use category 3 cable for all of their installations. This is the standard cable for both ISDN and 10BaseT ethernet. Because of the generally small extent of the cable plant, Category 5 cable is not necessary in the home. If you are expecting to upgrade in five years to 100MHz 100BaseT, then the Cat 5 cable is probably a wise investment.

You should have the standard RJ-11 sockets for phone and RJ-45 sockets for data. Do not let the phone company sell you special "data grade" RJ-45S sockets. These are for special leased line data services like switched 56. For more information on wiring, read Frank Derfler's and Les Freed's book: "Get a Grip on Network Cabling" from Ziff-Davis Press (1993).

Figure 1 is a topological drawing of my house's cable plant.



Figure 2 is a topological drawing of the localtalk passive star. We are using three of the possible four branches to connect up the three rooms and it works great. (Well, as great as LocalTalk ever works).



Outline

  1. Everyone gets a machine.
  2. ISDN & the internet.
  3. Virtual Office ISDN Daisy Chain.
  4. House Network Topology.
  5. Eunuch the Unix machine - Not!
  6. LocalTalk looks good compared to ISDN!
  7. BRouters v. Bridges.
  8. Back Off - Retry.
  9. Send your Network URL to BH&N.
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