Wireless Networking

Chapter 5: Dateline February 2002.

Here at the ranch, computer adventures never cease. Last summer we had the opportunity to be an 'early adopter' of two way satellite for broadband internet communications. This was an experience at first but finally settled down.

The technology consists of a KU band Satellite dish which looks very much like the KU band dishes that are used for TV service, except that they are bidirectional. The provider that I have used is 'starband' as in "www.starband.net" From the dish you run two coax cables (a receive and a transmit cable) to a 'satellite modem' located indoors.

In the late fall of 2001 Starband upgraded from a '180' hardware configuration to a '360' model satellite modem. This upgrade resolved most of my difficulties. The performance varys but compared to dial up service which out here in the boonies barely worked it is real fast. I never could get dial up faster than 19.2k and usually slower, and if you wonder why this website is designed for narrow band, it is because most of the time when I was writing the corp of this site I couldn't get more than 9.6k dialup speed and I need to be able to view the site myself.

Starband fixed all that, and I am eternally grateful for the broadband service. We are still pretty exclusive--at latest report I heard that they had 40,000 subscribers in the US which considering the millions of internet customers isn't a whole lot. Spectrum is at a premium with satellite service and they don't want you using the service as a web server, so the uplink speed is petty modest (128k)---only ten times faster than I got with my dial up, but the down link is fast enough that I don't hesitate at 50 megabyte downloads.

The starband satellite modem comes with an Ethernet connection on 'your side of it' but it is a bit of a nonstandard connection, implying that it cannot be fed to a hub or a switch---it is only suitable via a cross over cable to be fed into an Ethernet network card. This implies that to network the Starband system you need to 'dual home' a computer by putting 2 network cards in it.

Dual homing is not really too difficult. It is a little easier if you use 2 different brands of network cards, because otherwise it is hard to tell which card is which. The card that is connected to the satellite modem will be DHCP enabled as it gets its IP address from Starband. The second card must be hard coded with a local IP address as it will be the root of your local network. If you are smart you use a non-routable IP address for this. I then installed a proxy server on this computer (my choice was WINPROXY---a proxy server that supports Starband) and I was in business. You don't have to use a proxy server, and may just use the dual homing support built into Windows 98 second edition and later versions of windows, but I wanted a little more security than that. One of the good things about using a proxy server is that they have a place to take a virus checker, so you can have one virus checker that guards the whole network, instead of depending on each workstation to catch the viruses before they spread around the network. Anyhow the second network card goes to a hub and from there to the rest of the network.

If you use a proxy server, you then have to point your web browsers at it, which implies a bit of a special setup for each browser, but the result is a fairly decent security system, and one that is apparently fairly common in the industry. Proxy servers tend to be hated because they have so many options and are difficult to set up. While it is true that they have many options for set up, I have found it pretty straight forward.

Once the server is setup then come the hubs and other, computers. In my case I simply have a slightly modified peer to peer network. My so called "server" is just a Windows ME based PC. Winproxy, the proxy server, provides DHCP services, and WINS services within the network.

The first priority with a network is to keep the server running no matter what. Since we live on the end of the electric utility line (literally) and response time in the best of conditions is 2 to 3 hours, an APC XL (extended run) UPS was in order, along with extra battery packs.

The usual UPS that people end up with is usually only good for 5 minutes. Obviously in my situation such a battery backup would be next to worthless. It would ride through the blinks of the reclosers, but other than that accomplish not very much. So Off to "Ebay" I went and rounded up an APC 700XLNET UPS. I didn't need a monster of wattage, just lots of battery capacity. Ths model has about a 40 lb battery in it, I then added 3 of the 24 volt battery packs to it which weight about 80 lbs each. This has given me battery capacity to sustain the server, the satellite modem and the master network hub for about 8 hours. I figured this was a reasonable safety margin over the typical 2 to 3 hour outage that I usually see several times a year.

Networking for the ranch wasn't to be complete until I figured out how to extend the network to all the ranch houses. I knew right away that copper wasn't going to work because it is limited to 300 feet or so, and I needed to go 3/8ths of a mile over a hill. I next considered fiber which is the classic solution, but I didn't know how to work with fiber and it would have required a lot of digging. I suppose I could have learned, but another option appeared, WI-FI, as it is called. As loggers we have a lot of experience with radios. The first CB radios we had were filled with Vacuum tubes. Later the loggers association established a regional network in the 450 mhrz radio range, and we have long had a FCC license of our own in the band area, so most of our rigs have these days a CB radio, the 450 mhz band two way, as well as a cell phone for use when you actually get somewhere that they work.

With over 30 years of 2-way radio experience under our belts, the thought of using radio microwave for data transmission amoung our ranch houses didn't seem very radical. Back to Ebay and I grabbed some CISCO 342US wireless bridges of the 802.11b variety which took external antennas. Since these 100 milliwatt microwave units work in the 2.4 ghz band area they are pretty much line of sight units, and I had a hill to content with. Fortunately, the shop was on the hill between a couple of the houses that needed service, so the shop got a repeater. It is a little bit of a drill to configure these wireless bridges, but what has amazed me is how trouble free it has been. I"ve had 5 brige units interacting with one another for 8 months now, and exactly once have I had a service failure. One of the bridge units crashed once, and had to be rebooted. You can visit the bridges via telnet or with your web browser, and the crashed bridge looked fine when visited in this fashion, but it didn't work, and on physically inspecting it, the idiot lights indicated a problem, and nothing would go through it. They can be remotely rebooted, but it never occurred to me that was the problem until after I went and looked at it. Then I simply manually rebooted it, and all was well.

One thing to remember if you are wanting to use the web browser for looking at your WI-FI transmitters inside your network---The the browser is pointed to the proxy server and will try to find these things on the other side of the proxy server, unless you put the IP addresses in the exception list. If you are using Explorer, you point the browser at the proxy server under a button called "LAN SETTINGS", and there is a button within that area called 'ADVANCED" which will allow you to insert exceptions. This exceptions list needs to contain all the objects on the inside of the network that you want to view with the browser. I can't think good enough thoughts about my experience with wireless bridges. The cloud is that like everything else in the computer world, the technology is evolving. The 802.11b technology is a 11 mbs technology---just barely faster than 10baseT, and when you run it through a repeater, you lose half the speed as the radio has to take turns listening and repeating and of course everyone is always looking for something faster. The year 2002 has blessed/cursed us with the 802.11a protocol and the 802.11g protocol. Both acheive speeds of up to 54mbs, and at this writing it is not yet clear which of these higher speed wireless protocols will predominate. I'm sort of rooting for the 802.11g variant because it uses the same frequency range as the 802.11b, but I think you will need to stay tuned until next year to see where that all goes.

I'm not under any great pressure to upgrade, since everything is working just ducky, and the performance that I have is greater than Starband can dish through. The only cloud on this is that I have rounded up a large format printer which is available to the network. Those HP Designjets are real happy to have 100 megabyte graphics files thrown at them, and files like that can really stress a low performance network. Shucks, they stress everything. They remind me of the days when I used to wait for a spread sheet to 'recalc'. Now if that doesn't date me.

DATELINE NOVEMBER 2003

Well the wireless network has been in service for just over two years now. About 6 months ago one of our 4 CISCO AIR-BR342 Bridges ceased to function reliably. We didn't think too much about it and changed it out and went on, but in the last month all hell broke loose. The wireless network which had been invisible and out of sight and out of mind started mostly not working. None of the error messages made much sense. The basic symptom was that periodically, the bridge would disappear from the system. The log message from the Cisco Unit would say that it couldn't find the server. You of course couldn't find it either during these times. A Ping would provide no response. This problem would just fade in and out. After about a week of this we finally got our hands around the problem. We finally traced the problem to fading power supplies for the transmitter units. If the power supplies had just died it would have been easy, but instead their voltage output faded. The Chinese power supplies are rated at nominally 18 volts. At no load they seem to put out about 22 volts. The new one that we bought will sustain 20 volts under the load of the unit, but the suspect ones would fade to about 16 volts when they warmed up and were loaded. With some examination we determined that the CISCO bridges either won't boot, or reboot themselves when the voltage drops under 17 volts. Of the several we have there seems to be a little variance at just how low a voltage they will work on, as we had one sick power supply that would boot one of out bridges but not another.

In our case the diagnosis was particularly difficult because the root transmitter was one of the culprits and the second most important in our topology was the other culprit. I spent several days trying to diagnose this because I kept getting mixed signals as to what the problem was. IT took a while to figure out that I had 2 intermittent problems which accounted for the mixed signals as to where the problem was. Worse it took us a while to figure out how to test the power supplies as the superficially seemed to work. The big 18 volt power supplies have a cover which you can unscrew and have a fuse inside which provides a pretty good place to take a voltage reading. What really tipped us to the problem was that we took a suspect power supply that was cold, and plugged it in, and plugged the bridge into it and watched the VOM meter over time as the power supply warmed up. That power supply started out at 17 volts under load--and the bridge booted up as it should, and then the voltage started to slip toward 16 volts, and low and behold, the bridge rebooted itself, or at least attempted to reboot. Actually it started to reboot and then just went to sleep with a center red light on which is an error code for a 'software error'

Once we got focused on this we checked the input voltage--and it was right one at 124 volts. --- We have always had these power supplies plugged in to American power Conversion UPS units so we are pretty confident that the input voltage isn't the culprit.

Next we started our research on what the voltage ought to be. We were satisfied that 16 volts wasn't enough since our bridges wouldn't boot at that level. We check out a new Cisco Aironet Power supply and found that it put out 20 volts under load which has left us in a quandry since they are all rated at 18 volts. The thing that we did find out is that with a little more voltage any and all of our CISCO units work once again, including the one that we changed out 6 months ago. We have approached the cure in two ways.

First we have purchased some more Aironet / Cisco chinese power supplies. Given their history of mass failure in less than 2 years I think I know what to expect from them. The second thing that we have done is to visit Fry's and pick up a couple monster power supplies intended for laptop computers that happen to be 18 volt output units. They are 65 watt power supplies that have the output voltage adjustable. (The Cisco chinese units are 35watts). We have had to guess what voltage to set. What we know is that the no load voltage of the OEM units is 22 volts, and the loaded voltage seems to vary between a usable 20 volts and an unusable 16 volts. As I write this we are still trying to decide whether to use the nominal voltage (18 volts) or a little more---say 19 volts--given the the working power supply that we hve puts out 20 volts under load.

All I can say is that at the moment I am a little beaked at Cisco for selling very spendy bridges with cheap (Not that Cisco sells them cheaply) Chinese power supplies that won't live 2 years.

Dateline December 28,2003

My how times change. I spent this Christmas assembling some hardly state of the art computers. AMD2800+ CPUS, 80 gigabyte hard drives and 1 Gigabyte of ram. These are a long ways from the latest and greatest technology, but it still is nothing short of amazing. It seems not the long ago that I put my spreadsheets on manual RECALC so they system wouldn't get CPU bound.

They will be replacing a couple of 233 systems that are still lurking around. The 233's were a couple of steps down from the state of the art in 1998 when I bought them. Oh how the box has changed. The color is about all that is the same. There is little opportunity to upgrade. We have moved from AT cases to ATX cases. The keyboard connectors as smaller, and now we have a mouse port instead of using a serial port. Gone are the separate sound cards and network cards. Floppy drives have become largely irrelevant, and zip drives less interesting. CD burners are standard. My, My!.

DATELINE May 2005

Well, it has been over 2 years since I wrote another section. It seems that the computers of the last few years are born to die. As soon as a cooling fan goes, they are gone. I've spent the last year scrambling around trying to rebuild/replace the dozen or so computers that I have to keep track of not so much for better performance, but just because the old ones died.

I haven't rushed to the latest and greatest, trying to stay in the sweet spot of the price curve. In perspective, however, there is do doubt that moving beyond WIN 95 and WIN 98 and WIN ME is a good thing just in terms of stability. I used WIN ME as the server for my satellite dish for several years. It never could run more than about a week without crashing. When the Satellite IA7 was down last winter, I went through a bit of hell getting things going again and upgraded to a computer with WIN 2k to run the satellite software (and server as an informal file server for one of my networks). Windows 2000 will run for months without crashing. A big difference.

DSL arrived at my office, and I promptly installed a server for it and put WINPROXY on the dual homed server to spew the internet around that network. I keep the virus checker in Winproxy going, and it guards the whole network, a good thing I think. If you rely on virus checkers at the individual workstations the defense is only as good as the weakest link.

My upgrade of the month is an effort not quite achieved to upgrade my office network from a windows NT server to a Windows 2000 server. The NT machine has been sitting there running trouble free since 1998, and it isn't a high price server box at all, it is just a Gateway 233 desk top with a meager 64megs of ram and a 10 gig hard drive. Seven years of trouble free service is pretty good, but I think I am pressing my luck. I've got the files moved over and if I can ever figure out how to install the active directory in W2k I'll be able to pull the old NT machine off line. My new server is still a cheap box, but in a bow to reliability, I did hang a couple 80 gig hard drives on a cable inside and used the software RAID in W2k to mirror them.

I've had a real run on DOA motherboards in the last year or two and it seems the the more money I pay for them the less likely they are to work.

Hewlett Packard HP 8200 Scanjet

My latest and greatest toy is a HP Scanjet 8200. The things are dirt cheap are are they nifty. I've had an UMAX 1210 around for a good many years, but I can't say enough nice things about this Scanjet 8200. I go around to set it up today after looking at it for a month or so, and the setup was a breeze. Plug it into an USB port, plug in the power supply, and install the software and it was ready to go.

The only thing I found out for sure was that it is a lot smarter than my computer. I was interested in high resolution photo scans as I sometimes want to blow them up to really large sizes to print on my Plotter. I right away figured out that I didn't have enough memory in my machine for that game. I had only installed 650 megs of RAM and that doesn't cut it. The computer I put it on has an 'el cheapo' motherboard in it that only has two memory slots. With all the issues I've had getting DOA motherboards I bought a MOBO with CPU (a Semperon 2400) with 128 megs of RAM. When the system worked I stuck another 512 meg stick in it and hoped to be OK. Well forget it. If you aren't going to want a picture bigger than 8x10 that might due, but I ran out of RAM long before I approached the limits of the scanner. It was fairly easy to upgrade to 1 gig of ram--- I just changed out the 128M stick for a second 512M stick, but this still isn't enough to take the scanner to its limits. I'm not sure a Semperon 2400 is either, but the real delays come from thrashing virtual memory, and you don't have to try very hard to make a 1 gig file.

I even managed to cause my local server a fit. I scanned a 35mm negative at 9600 DPI, producing a 600+ meg file and then tried to print it 11"x17" on my HP 2500C which uses my starband server as a print server. The photo was cropped somewhat on one side, and I got a little screen message that the server was making some more virtual memory. I am reminded that I only set that file server and print server up with 256 megs in the first place. It is really a Peer to Peer network here at the ranch, but I run WinProxy on that computer to distribute Starband and use it as a file server for shared files and it works as a print server as well since I have a network card in the HP 2500c.

Yet another Laptop

Years ago, I bought a Nec Laptop and used it for stuff that needed DOS which my desktops were all on CPM. I kept it right up until my wrists started hurting and I thought about either dumping the laptop or dealing with Carpel tunnel and the laptop went away. Now years later, I have ordered another. I have promised my self I won't use it much, but having a laptop has become a traveling necessity. Every Motel that is worth its salt has wifi or hardwired Ethernet these days and Email goes on whether you are on the road or not, so I got one to take on the road when I travel. Also I am on a few Boards and they are common around the board table as well. Indeed Board rooms come with Ethernet net connections and electric plugs these days. I should have purchased a light weight one because I am going to pack it a lot, but alas, I didn't. I got a Sony 8 pounder off of UBID. The price was right $950 bucks for a K33 model that is suppose to run somewhere around 3 gighz and have most of the features of a desktop including a 15.4" screen, but we will see. I know I can't stand the 'mouse pads' so I will have an external mouse. I have a Dell 810 Latitude on loan from my last business trip. It is a few years old and just as heavy. I found it far more usable with a real mouse. The Dell runs on w2k and seems to take forever to boot, and like my NEC of years ago, the batter lasts about long enough to get the computer booted so it can tell you that the battery is about to croak. The real improvement in the last many years is in the screens. The Old Nec had a barely readable monochrome screen whereas these new flat screens are really nifty.

CP3500 HP Plotter

It doesn't look like I remembered to mention it, but I managed to acquire a CP3500 plotter a few years back. I real big monster---it is about 8 feet long and takes 54" paper. I don't really know why I bought it, but it has been fun now and then printing maps and giant photos. It really gets spendy to keep around because the ink cartridges cost $150 bucks or more a piece, and a lot more if you want the UV resistent ink. The cartridges hold about a pint of ink and last a long time but...... Printing big photos 4 feet x 6 feet has been quite a challenge with it. It presses the hardware to the limits. While the printer has a hard drive built into it, and I upgraded the printer to as much memory as it will take, you still have to use special options to format the large photos in the computer, as the printer just doesn't have enough memory to do it. To keep the files managable, what I have usually done is to avoid making a really large photo in the computer.--- instead a I make a smaller one usually in Adobe Elements and then set the printer driver to 'zoom to paper size' when I print. This seems to work better than enlargeing the photo to 4 feet in Adobe. You can fill up the house fairly quickly when a 4x5 photo means 4 feet by 5 feet but it is a lot of fun. Line drawings and maps take a lot less effort. They do take time to print however. The print time for a 4x6 foot photo is in hours not minutes. The computer horsepower to handle the file sizes necessary for these big plotters is really struggling. The software is mostly Kludged, and the wait times can easily get out of hand.

PRINTER PRICES DOWN

I haven't paid much attention to printer prices for a few years, and just now got to thinking of replacing my bemoth 2500C with something I could carry. I was shocked at the drop in prices over the last few years. I remember all too well paying several thousand dollars each for a variety of printers over the years, and now most are priced in hundreds,not thousands of dollars, and they do really nice work.

In other news of the day, the 802.11b wi-fi seems to be on the way out, being surpassed by faster technologies. There are still a lot of things happening in the Wi-Fi world.

Windows XP

I was going to talk about WIN XP but never quite got around to it. I stayed away from it for a long time, but I have to admit that it is better. It just does somethings right. The Dos box works right with a mouse for example (unlike W2k), and the networking and installation issues are much more hassle free. I can't quite get use to the interface and generally set it to backwards compatible for the interface, but the function is simply better. Getting printers to work has been a hassle for as long as I have used computers, and XP does it the best yet. Plug an XP machine into a network and it runs around looking for printers to hook up to. I have no idea how much time I"ve spent in the last 25 years trying to make shy printers respond.

At this point the only reason not to migrate to XP is cost. I've got a lot of computers that aren't used all that much and a clean upgrade would cost a fortune, but I am working at upgrading them one at a time as the opportunity presents itself.

- - Updated 12/16/2012
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