What was planned as an afternoon's work filled three days. After reading many of the online references, we were left in confusion over which components to use and how to configure them. This paper is our first experiment in post-modern technical literature, a guidebook where the narrarator is as clueless as the reader where we discover the answer together. This will be part diary and part a compilation of our notes in migrating our SOHO network to support wireless. This document is not so much an authoratative guidebook as it is a travel log tracing our journey.
The Teledynamics offices are located in the maple-wood forests along the eastern shores of Lake Huron, about 220km northwest from Toronto Ontario. Broadband in this neighbourhood sometimes seems a pipe dream. Despite promises by Industry Canada to deliver 1.2Mb/sec bandwidth by 2002, the current best-choice for broadband is the 700kb/s asymmetrical Avarion/Breezecom wireless system from Datastore, a 400kb/sec asymmetrical connection through Hughes Satellite systems from Internova, and a new land-line based circuit called ‘Superlink’ also from Internova. All but the wireless are bound to Windows and all of them carry a cost of entry of about $2000. Thus it's become evident that if we want home broadband, we'll need to roll our own.
Wireless networks, and especially 802.11b wireless, are probably the future of last-mile broadband for rural and remote regions. Components are cheap, the network can potentially deliver upwards of 11Mb/s and there is a wealth of free online documentation and opensource initiatives. Armed with this realization, we set out to learn how to install and configure a wireless network as the first tiny step toward understanding how the technology might be deployed on a community level, and also to understand how wireless community networks might actually be used by a geographically local community. Our explorations were inspired by reports such as the O'Reilly home-LAN recipe[SE] and another ORA-sponsored project that described an as yet unbuilt project to provide rural broadband through the use of low-cost 802.11b network connected through discarded satellite antennas; their system claims 11Mb/sec bandwidth across 20 miles, and our location is a scant 10 miles up a concave shoreline from broadband suppliers in Port Elgin.
Taking our first steps required basic understanding of compiling kernel drivers, understanding the wireless drivers and how they relate to the various vendor products, and then configuring a router bridge between our wireless network and our Internet gateway.
The good news is that it worked, as showed on Soleica.
Part of the struggle as a newcomer to wireless is the jargon, and the plethora of alternatives. The following are some of the more confusing terms we encountered and our naiive understanding of them:
This defines the standard protocol for encoding and moving data packets across the radio, including a basic (non-functional) authentication scheme.
One of the 802.11b operating modes, often called ‘AdHoc’ mode. It is ad-hoc because it has no central base station; an ad-hoc network will exist so long as any members of that network remain on the air.
In this mode, one station is central to the network and all others are simple STN nodes. This is the most common mode for dedicated wireless gateway devices and is probably a necessity for a wireless network of any size. AdHoc works fine for a handfull of nodes, but to scale up for a community network, you will need HostAP support.
Each wireless network is assigned to one of about a dozen radio channels (frequency), which is obviously insufficient for any densly populated area. Individual networks are identified by their SSID code, an arbitrary string known to all nodes within that network. Quite often this is the host site's telephone number, but any unique string will do. Cracking into an unsecured wireless network is simply a matter of guessing the channel and then scanning that channel until you intercept the SSID broadcast.
Bridging is a technology for restricting traffic between two network segments, with a useful side-effect of being able to combine two physically different networks into one logical TCP/IP subnet, for example, to have both your Ethernet LAN and your wireless network appear to be under the same 192.168.70.* network address.
A dynamic host allocation server that listens for broadcast requests from an unassigned node's network card and then binds that MAC (machine address) to the assigned Ethernet address. DHCP protocol can also set default services such as NNTP and webservers, DNS, and gateway routers.
This is a feature built into the Linux kernel and causes a computer to mirror traffic from one network interface to another.
A firewall technique where the original of packets is re-written by the gateway/firewall machine such that hosts outside the firewall will see the packets as originating from the gateway host rather than seeing the internal LAN address. This also means that incoming connections will be unable to find the hidden machine unless the gateway is also running port-forwarding software.