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4. Summary

Our wireless routers have been in continous operation since Oct 5th, 1998. We have had only three major outages - the first two related to windy weather skewing the antennas, which we fixed by crimping the antennas down tighter. The last outage was due to the very severe weather conditions around the thanksgiving holiday. We ended up writing a script to lower the bandwidth arbitrarily on each side, and managed to stay up at the 384K setting for the remainder of the day. As it turned out, the downstream antenna had been knocked slightly askew this time, too. We've otherwise managed to stay up at the 1Mbit setting going 13.1 miles through wind, rain, storms and fog with nary a blip.

The only ongoing problem that remains is when 3 of us start playing quake (The game uses udp and sends enormous numbers of packets), the downstream router tends to stop transmitting for a minute or more at a time. Most of the evidence we've gathered to date suggests that the wireless card itself is not at fault but the ne2000 cards, so at some point we're going to upgrade to Netgear DecChip tulip based cards. (And incidentally, gain 100Mbit/sec capability). We are also not currently running the latest arlan drivers.

The natural congestion management of the TCP protocol means that we NEVER see this problem when doing normal things (ftp,web,email,etc), and it also does not occur via NFS (also udp based), which is puzzling.

This project cost us lots of time, but we saved lots of money. The arrangement we worked out with our downstream ADSL guy was 2/3s of the cost of his ADSL - 154 bucks a month. The ADSL install charge from pac bell was 450.00. The total cost of all the hardware we bought was less than 3k.

The downstream router not only handles the wireless stuff, but has 2 network cards enabling it to do traffic shaping for the guest network. The upstream router has a modest amount of firewalling features turned on so we don't have to deal with people trying to hack or portscan us.

Ultimately we plan to build a SBC based solution using flashdisk technology and the PCMCIA version of this same card. Elmer says his current driver works now on the PCMCIA cards... we have the flashdisk stuff going... the single unit cost should be less t han 2k, easily... now to get more funding...

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