Chapter 2: Hardware


Still to be determined. The center point of our design is to use freeware off the shelf products as much as possible in as many places as possible, so any box that runs Unix (or a close clone such as Linux) would be of interest.


The Free-Net uses a '486DX2-66 with 4 MB RAM, and a 420 MB hard disk running NetBSD as a firewall machine. The Free-Net's firewall does a simple task, protect the Free-Net against the world. We have a somewhat more complex task, us against the world, and our sites against each other and us (the thought that users at one site might attempt to hack another site can not be ruled out...).

On paper one firewall could serve all of our needs. However for reasons of reliability, simplicity and load I would suggest that we plan on at least two firewalls (one for us vs the world, and another for our site vs each other and us).

Terminal Servers:

Terminal servers do two things, first they do some of the grunt work in controlling modems (telling the modem to pick-up the phone when it rings, etc.). Second terminal servers handle the physical connection of the 30 - 100+ modems to the system.

The reduction in workload on the computers would for us be enough reason to justify the terminal servers.

Both the Portmaster and the Annex III terminal servers are highly thought of in the industry (and I have some very possitve hands on experiance with the Portmasters). Cisco Systems has a very good reputation in the bridge and router markets, but trust me, the pain connected with their terminal servers isn't worth the trouble at any price.


We will need a modem pool. The goal will be to a few modems as possible, and make sure that as many terminals are hanging off each of those modems as possible.

The first question is in our case, what can we get cheap (or better yet free). We will need to worry about modems for our central site (which lends itself to rackmount modems) and at the community access points (where standalone modems would be the choice).

Community Access Terminals

Our centerpiece is the hope and plan to have terminals in many public locations around Metro Toronto. The concept being that not having a computer/ terminal and modem should not be a barrier to accessing the Toronto Free-Net.

This will mean long term getting terminals into some of the oddest of places. Apparently the "Community Memory" project in San Francisco (a Free-Net like project) has had excellent results putting some of their terminals in laundromats.

Public access site layout:

A key point in our plans are the public access sites. A dedicated line can be run over a few blocks for a very reasonable price (under $25/month). For a typical location we hope to set-up a something like the following:

Public Access Site: Us:

+----+  +----+  +----+  +----+

|8088|  |8088|  |8088|  |8088|                   Other

| PC |  | PC |  | PC |  | PC |                   Links

+----+  +----+  +----+  +----+                    |||| 

  |        |      |        |    +----+           +----+


          Ethernet link         | PC | Dedicated |wall|

                                +----+  Line     +----+

                                                    | Link

                                                    | to

                                                    | system

The set-up above would use the cheapest ethernet cards available on 8088/8086 IBM PC compatibles.

+----+  +----+  +----+  +----+

|8088|  |8088|  |8088|  |8088|

| PC |  | PC |  | PC |  | PC |------+

+----+  +----+  +----+  +----+      |

  |        |      |             +------+             +------+

  |        |      +-------------| '386 |-------------| Fire |

  |        +--------------------|  PC  |   Dedicated | wall |

  |                             +------+   Line      +------+

  |                                  |                   | Link

  +----------------------------------+                   | to

      RS-232 serial link                                 | System

The above with the '386 is a variation on first design. With this option we would use a machine running NetBSD/Linux and then run the 8088/8086 machines as dumb terminals. The trade offs here are that we trade of the cost of ethernet cards for a multi-port serial card (in SOME situations this could be cost effective). Another trade off is that, with thin ethernet the machines can be spread out over several hundred feet, while with the RS-232 links should be kept to under 50 feet.

We will go with which ever arrangement is the least cost workable solution at a given site.

For some locations we are going to need to protect the terminals. The "Community Memory" project's approch in San Francisco was to build a stand-up terminal case out of thick plywood, with the front of the monitor covered by a sheet of plexyglass. The case was set-up so that the keyboard was held in place so that it could not be moved or removed. Over the keyboard they had placed a "keyboard skin" (a thin rubber membrain) so that spilling liquids over the keyboard would not cause damage.

Other bits:

Busy outs:

A small but very useful item for an ISP is the "busy outs". These consist of a short (approx. 15 cm) cable with a male RJ-11 connector one end and at the other end a pill bottle containing a 620 ohm 5 watt resistor. When the RJ-11 connector is plugged in, the 620 ohm resistor appears to the Bell switch to be an off-hook telephone.

When we have had cable problems with the terminal server that we could not deal with immediately, or when we have had problems with the load on the login servers and had to temporarily limit the number of phone users logging in, the busy outs have been fantastic. Here we can keep lines from ringing with no answer (which many users find very annoying). We have over one hundred busy outs stored at the Canadian Home Shopping Club.

The cables and resistors were purchased from Active Surplus on Queen St. The pill bottles were purchased from the Shoppers Drugmart near Yonge and Eglinton. Keep in mind that 5 watt resistors are overkill in this application, but they were so cheap, well, why not... Also, the reason for the pill bottles is two fold first to insulate the resistors and keep the bare wires from touching anything else. Second when in use the resistors can get hot enough to be very unpleasant to touch (not quite hot enough to burn), and the pill bottles keep people from the heat.

Building a busy out:

Parts required:

Tools required:



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