Better at a Distance

I have a Compaq laptop acquired a few months ago. While originally it worked well, presently it fails to make a useful connection if it is near the router, but works better at a distance of perhaps 40 feet, in another room. Since I have two wireless routers, I think that we can rule them out. (For tests, I always have the wireless turned on in only one router.)

What are possible causes of this problem?

Thanks for your help. Mike.

Reply to
Mike -- Email Ignored
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On Fri, 09 Nov 2007 16:26:30 GMT, Mike -- Email Ignored wrote in :

Interference. See list of possible sources in the wiki below.

Reply to
John Navas

[...]

The problem appeared without any change in relevant environment.

Mike.

Reply to
Mike -- Email Ignored

On Fri, 09 Nov 2007 17:01:17 GMT, Mike -- Email Ignored wrote in :

How do you know that aren't any new sources of interference?

Reply to
John Navas

I haven't brought any new electronic things into my house.

Reply to
Mike -- Email Ignored

On Fri, 09 Nov 2007 17:28:09 GMT, Mike -- Email Ignored wrote in :

Are you sure? Really sure? Otherwise... It could be caused by malfunction. It could be caused by a neighbor. It could be caused by the city.

Reply to
John Navas

Why not try checking to see if you can reduce signal strength in your router.

Reply to
Cal Vanize

Interference. However, the interference is not entering at the router end. It's getting to the Compaq laptop. (Interference can happen at both ends of a link). If the interference is maximum if you're standing near a window, it's almost certainly coming through the window.

Possible sources are many but can possibly be identified if you offer some sort of pattern. Is there all the time, or only erratically? If erratic, at some specific time of day? How long does it last? Etc. Your laptop may also have some way to display the signal strength and signal quality. What you'll probably see is that the signal strength is better when you're close, but the signal quality may get worse due to interference.

You can also install Netstumbler on your laptop, and use the indicated signal strength and quality to do a site survery around what I assume is your house.

If Vista, use Visumbler:

Reply to
Jeff Liebermann

It might also be beneficial to have a look at what channels are being used within close range of your system. It might be better to select a channel that isn't being used and set it in your router. See how that works. (No need to change the SSID.)

Reply to
Cal Vanize

Yep. Channels are important. However, the latest generation of wireless access points arrive by default with a channel selection of "auto". The idea is for the access point to automagically select an empty channel. In theory, you don't have to set your channel or find an empty channel.

It sorta works, but I have my doubts. For example, I'm not convinced that it can detect networks that don't broadcast their SSID. What I've also found at one customer with DI-624 wireless router and one DI-624 acting as an access point, is that they both radios ended up near one channel after about a week. I would have expected them to end up at opposite ends of the band, but that wasn't what happened. I have no idea what went wrong, so I just disarmed this feature and manually set the channels.

I've also received calls from customers complaining that "it was working just fine, but now I seem to be getting interference". At first, I was blaming new wireless network arriving in their area. Upon further tinkering, I found that they had automagic channel selection enabled and it had landed on a rather bad choice of channel. When I disarmed the feature, sniffed a bit, set the channel manually, everything was back to normal.

While I'm ranting on the subject, I also found that it was very difficult to get a wireless router in auto mode to change channels. I tried every trick and source of interference I could find and never got it to reliably switch channels. However, it would sometimes switch without the slightest provocation. I have no idea what algorithm is being used, or exactly how it's suppose to work. My current guess is that it only switches when there's no traffic, making it useless for selecting the channel with an active connection.

Reply to
Jeff Liebermann

At boot / reset. But maybe not dynamically.

On both our Gateway 7001a/b/g and Cisco 1121g, the clearest channels are selected at reboot or power cycle as default. Both settle in on what is good, but only at boot time. Boot time might not reflect average conditions throughout the day.

My suggestion is to try fixed channels to see which one(s) work the best most of the time. Select that channel in the A/P. that will help overcome

Yep. But beyond that, performance needs to be checked throughout the day as well as periodically. It could very well be that at times during the day several wireless devices (A/Ps, routers, PC, whatever) are in use on a channel that would otherwise be OK the rest of the time.

Reply to
Cal Vanize

Cal Vanize hath wroth:

Nope. I tried that and found that the DI-624 always came up on the same channel that was last used. That makes sense because you don't want an AP reboot to reset all the existing wireless connections. Rather, the connections should continue from where they left off. Other AP's that I've tried are totally random on initial channel selection, with zero consideration for existing traffic. That's how some of my customers AP's landed on heavily used channels.

I think (not sure) that this is the applicable patent:

Note that the initial selection is random, followed by reselection at random intervals:

"Within a radio access network (111, 112) an access point (181, 182, 183 and 184) selects a channel by first randomly choosing a channel from those available for use. The Access Point then monitors the channel for a random interval to determine if the channel is presently carrying traffic. The Access Point will select the channel unless the channel is in use by another AP. If so, then the AP will select another channel and commence monitoring for a random interval in order to determine whether the channel is available. The AP will continue to choose channels until a suitable channel is found, or all available channels have been exhausted."

How do you know it's the cleanest channel that it initially selects? It could be random and you would not know the difference unless you had a spectrum analyzer or channel scanner program running.

Agreed. Fixed channels are probably better than auto. Some trial and error will be necessary.

Yeah, I've seen that. I have several customers in high rise buildings, with glass walls, that are facing other high rise buildings. The Wi-Fi interference is fairly bad, but the microwave oven interference is really awful. During coffee break, lunch, and afternoon loafing times, when the microwave ovens are doing their thing, Wi-Fi comes to a grinding stop.

Reply to
Jeff Liebermann

HAHAHAHAHAHAHAHA!!!

A DI-624 is a home networking toy! Hardly anything on which to base any reliable network or a kind of discussion of connection quality! I'm not surprised you get strange and variable results.

Besides, it hardly even complies with THAT patent.

But still its better to "survey the airways" with a PC to determine channels that aren't in use. Combine that with a good scan at boot time and there may be channels identified to start fixed channel testing.

No, its not random. Both our A/Ps scan all channels (confirmed in the boot logs) and determine / select the best. I've noted that it detects and selects channels that have nothing else on them. Since the Gateway is the faster boot, it finds its channels (a and b/g) and the Cisco selects a different one. Both find and select channels with the weakest (or none) other signals. Consistently.

Don't think that the little wireless telephones don't play complete havoc with 802.11b/g wireless. That's why I've got an A/P with 802.11a and all our PC adapters are a/b/g. In case the interference levels knock them off of their primary b/g connection, they are on automatic fallback to the 802.11a A/P.

But that's just what we use at home.

Reply to
Cal Vanize

Cal Vanize hath wroth:

Yep. It's a toy. I'm too lazy to dig out the sales figured, but my guess is that DLink has sold at least as many wireless routers as Cisco AP's (if you eliminate Linksys sales). The DI-624 and similar routers may be toys, but they're very common toys. Besides, I like my toys.

If you read the questions that are asked in alt.internet.wireless, the number of questions about Cisco routers are few when compared to the large number of questions involving toy routers. It's a fair assumption that most users in this newsgroup buy and use toy routers, not Cisco access points.

I'll have to take your word for it as I have no way to test it right now. If I get the chance, I'll do some more testing. Doing experiments on the customers time is generally discouraged.

Agreed.

What I want for Hannukah:

Good enough if the log file shows how it decides. There's nothing useful showing on the toy routers in the logs. Does the Gateway or Cisco scan randomly for empty channels as the patent describes? I'm fairly sure the DI-624 does NOT, which means you're probably correct that it does not follow the patent description.

I have a 2.4GHz Panasonic KX-FPG379 fax/phone/answering-machine conglomeration. It's a bit smarter about dealing with wi-fi than my previous Panasonic cordless phone. I've watched it on the spectrum analyzer. It apparently looks for existing signals and plants itself on the opposite end of the band. If I set my WRT54G toy router on channel 1, the cordless phone ends up near ch11. If I set the WRT54G for ch11, the cordless phone ends up near ch1. If the WRT54G is on ch6, the phone seems to favor the lower channels. The previous phone didn't do that and would appear on random channels and sit there forever.

I should try my home WRT54G on auto, but I don't want to disrupt our neighborhood WLAN that's running on it. I'll play with it at the office, where I can do some real damage.

Reply to
Jeff Liebermann

But these are "toys" don't necessarily provide reliable service (and my point in using the term "toy"). Just cheap mass-produced [insert derogatory term here] that is compromised to a price point. And the compromises are against reliability and stability. They might look pretty but don't seem to hold up.

Agreed. Consumers trying to save a few bucks are vulnerable targets for this crap. Cheap stuff outsells quality most of the time. Cisco routers and A/Ps don't have the problems of the cheap junk so I would expect very few questions. I'm sure there are a lot fewer Cisco appliances in use except in serious applications where reliability and stability are valued.

There weren't many of the Gateway 7001s sold so I wouldn't expect to see many, if any, questions at all. At about $400 per copy, they priced themselves out of the market trying to compete against Cisco (with the Cisco reputation).

I see all kinds of complaints about cheap networking appliances failing all the time. D-Link, Linksys, other cheap consumer crap sells good and then fails relatively quickly. In the meantime, users having problems don't understand that the quality of this crap is really negatively contributing to their limited service levels.

Good quality components (Cisco, most 3Com, high-end D-Link / Netgear) typically provides reliable service and rarely fails. No resets required, no power cycling, no "getting lost" on the LAN.

FYI, a used Cisco 831 on eBay is about the same price, maybe a little more, than the network toys that fall apart in a few months. A Cisco

1121g recently went for under $100 inc. shipping, a 1231g for under $120 inc. shipping. These tools are robust and provide reliable connectivity. Put these on a UPS and they just never go down.

If you're charging for customer support, wouldn't you want to recommend better components? In the long run, wouldn't it be cheaper?

Both Cisco and Gateway appear to start at channel 1 and go through 11 for the 2.4ghz band. For the 5ghz band, the Gateway appears to start at channel 36 and works its way to 165 sequentially.

Both the Cisco and Gateway have set-up options for single channel selection within the bands they operate. Because of a particular vulnerability, the Gateway needs to be set to fixed channels.

Nice feature on the Panny. NOBODY in our neighborhood uses ch1 or ch11 because of the wireless phone issues.

Just out of curiosity, are you running separate VLANs for your WLAN? (Is that feature supported on a WRT54G?) And what kind of security / access has been implemented on the "neighborhood WLAN" to limit unauthorized access?

Reply to
Cal Vanize

Cal Vanize hath wroth:

How reliable would you like it? For the average home user, rebooting the wireless router every few weeks is no big deal. After some initial problems, router stressing protocols, such as Bitorrent, work quite well. Granted, I've seem some really bad junk being sold as wireless consumer grade products, but presumably one does not buy from the very bottom of the market.

Ummm... Considering the number of power failures and glitches we get every winter, I don't think uptime is a major issue. If I applied commercial ISP standards to the average home computer installation, literally every component, from the power conditioning, to the antennas, would fail to comply. That's why there's a difference between consumer and commercial. I have no problem with using commercial hardware for consumer applications. However, I doubt if Joe Sixpack is willing to pay the price.

Checking... well, my office WRT54G toy router, running DD-WRT v24, has been up for 5 days (when I did the firmware upgrade). It's been running for perhaps a year, with uptimes running around 4-5 weeks. Downtime is usually inspired by me wanting to try some experiments that require a power cycle. I think that's reliable enough.

"Trying" is a bit of an understatement. Even Cisco bought a cheap router company (Linksys) because they thought there was something good about the product. The consumers are not only trying, they've succeeded. There are plenty of user installed wireless systems that work fine out of the box and do not require a CCNE to configure.

No, they have other problems. Joe Sixpack can't program a VCR or DVR, can't set his digital clock, can't put the batteries into a toy, and probably can't configure a Cisco router. That's why the wireless industry has invented SES, AOSS and other setup aids.

When the cheap wireless router biz was configuring their routers with built in web based interfaces, I was doing battle with Cisco 25xx series routers in IOS from the command line. It may take a while for Cisco to discover and adopt simplicity from the cheap junk.

Sure. I have a few Cisco wireless access points and bridges in service. They work great. However, in the presence of interference and path impairment issues, they don't work any better than commodity wireless devices. Cisco's main advantage is in the weird and wonderful protocols that most home users don't need. To Cisco's credit, I've had no equipment field failures, while the consumer grade stuff has experienced all manner of disgusting failures.

Dell also tried that with network hardware, and gave up. I didn't mind them giving up on a bad idea. What bugged me is that they left their "loyal" customers hanging. Gateway did much of the same thing, but I think Acer might pickup the support. Dunno.

I don't. My guess is about less than 1% genuine hardware failure rate. Most of these are due to power glitches, idiot errors, or physical damage. My biggest headaches are the constant firmware updates required to keep ahead of bugs and exploits, plus companies that abandon their existing customers by NOT releasing firmware updates for known bugs. However, I'm fairly careful to avoid vendors and product that have these issues.

I think they're learning to tolerate it. Most consumer electronics is essentially throw away. Cell phones have an 18 month average life time. I suspect wireless routers run about 3 years before they are replaced. DSL modems about 4 years. I don't even wanna touch the lifetime of TV's and hi-fi. Not only does Joe Sixpack understand that he's buying commodity junk hardware, he likes it because of the low price.

Have you ever tried to sell Cisco hardware to a home user? I'm not talking about buying used stuff off eBay. I mean new, out of the box, with warranty, and possibly a service contract? I have and actually succeeded, once. I wish I hadn't because I was expected to provide what amounted to an SLA (service level agreement). The Cisco 826 DSL/router combo was fine, but the PBI/SBC/AT&T DSL service and phone lines were awful and accounted for most of the service calls. I lost money on this one.

I have specific issues with some of the allegedly high end D-Link and Netgear equipment. I've tried it and was not impressed. Most of it is re-labeled equipment from tiny specialty manufacturers. The large vendors stick their name on the box, offer zero support, and sell the initial production run. Then, they drop the product because the customers are complaining. The small company can't handle the support load, so that creates an essentially abandoned product, even while it's still being sold. Specifics if you really want them.

Yep. There's enough there that I could probably support my business re-selling used hardware. That makes Cisco hardware price competitive. However, the few pieces of Cisco hardware I've bought this way have all burned far too much time. All needed firmware updates. Some didn't work. I don't mind doing this, but it does take the edge off the price benefit. However, Joe Sixpack would never be able to do any of this. Are you suggesting that some of the users in this newsgroup purchase Cisco access points on eBay and deal with these problems? I hope not.

I'm almost retired, so keeping the phone from ringing is slowly becoming a priority. I want a happy customer but there's a problem. I rarely make the initial sale. My purpose in life seems to be fix the mess after it's totally screwed up by someone else. I do mostly troubleshooting, damage control, rework, and repairs. With wireless, it's almost always an installation or interference issue, not an equipment issue. Where I do find absolute junk or defective hardware, I'll sell a replacement.

I do better with the coffee shop installs, where I'm able to specify my choice of cheap commodity wireless routers. In this case, you're correct. I've been seeing problems that would best be solved with a better grade of hardware. I proposed a solution upgrading from Buffalo hardware to Sonicwall TZ-170w. The customer refused due to the price tag and now declares that he's willing to live with the problems. I don't think I would have done any better specifying Cisco.

I'm in an office complex with about 6 businesses. 5 of them have wireless. 4 of those are on channel 6. (I didn't set these up). All of them are happy because the wireless is lightly used (mostly visitor laptops and PDA's). I initially put myself on Ch1 and found that my

2.4GHz cordless phones start their scans at the bottom of the band. So, I moved to Ch11 and lived happily ever after.

No. I have "AP isolation" enabled in the WRT54GS router. That keeps the wireless users from seeing each other. The wireless part of the WRT54GS will not forward packets from wireless to wireless. I also use this in coffee shop installs. I have used VLAN's to isolate public and private wireless networks.

Not with the stock firmware. DD-WRT supports VLAN's but the firmware seems very beta. I had problems with wireless VLAN's and dual SSID's. However, setting up a separate VLAN on an ethernet port works fine.

EoIP (ethernet over IP) tunneling is also supported:

but I haven't had a chance to play with it. I've been told there are bugs and that it currently only works in bridge mode.

Lots of trees to block the RF. It's really crude and should not be used as an example of how to setup a neighborhood LAN. I use no encryption and MAC filtering. I monitor access with arpwatch. Someone could break in, but I would know about it rapidly. I've had more problems with "wiretaps" into the CAT5, coax, and fiber running through the forest, than with wireless. Not only does the security suck, the traffic can be sniffed. There's considerable old 802.11b WEP only hardware in the system that needs to be replaced. The only reason there haven't been problems is that I know all the neighbors within range (as limited by the forest). This would never work in my palatial office, where WPA-PSK is mandatory because even the local street bums have laptops and wireless PDA's.

I have a stand alone RADIUS server sitting on my bench (PC104 based) that I'm going to eventually deploy for WPA-RADIUS with 802.1x authentication on the neighborhood WLAN. The main consideration is that it makes no noise and draws little power. That means no fan and no hard disk. I'm trying to run the whole mess on a 1GB compact flash card, but I'm out of space. I should have a 4GB card shortly, which should be sufficient. I'm also looking at some stand alone authentication products.

Reply to
Jeff Liebermann

For the average home user, its a pain in the ass to reboot it. And typically rebooting occurs more frequently with the age of the device

How do you spell UPS?

Joe sixpack doesn't stop to think that he pays [insert $$ amount here for broadband] and gets pissed off wen he has problems in teh middle of an eBay auction. If he were to spend another $2 per month for a connection that didn't fail, he might go for it. Take one year's worth of that extra $2 and spend it on a good router and he gets what he wants.

It the responsibility of support technicians to educate those they support to help them understand the investments they make in support hardware.

But OTOH, it may just impact their job security and billable hours.

5 days!!! WOW, that's really impressing for a Linksys!! I just looked to see that its only bee five weeks for the power cycle of our Cisco. That happened because we put it on a different UPS.

And work great for weeks, maybe even a few months. Even Cisco knows that Linksys is just consumer-grade crap that won't last.

And if you check, it doesn't take much to configure a Cisco router anymore. They have web-based tools that work just fine.

Cisco 2500 series? Those are a little old, doncha think? Didn't they use those to stream live video of the sporting events at the Coliseum? The old one in Rome. You know "and the latest score is Lions 4, Christians nothing... And now back to the action!"

Modern Cisco routers have easier set-up. And even the 2500 series are workable. Plenty of set-up scripts laying around.

The difference is that Cisco A/Ps don't need to be reset. As you note, they are robust and last. The investment in hardware alone pays for itself for the life of the unit (not even considering the $$ spent in set-up time charged by support staff). They just keep going unlike the vast majority of the toys.

The interference issues are typically not with the A/Ps, they are with the radios in the PCs trying to communicate with the A/Ps.

The good news is that they don't require much support. Even the known bug in the Gateway A/P has an easy workaround.

Its been my experience and the experience of those I know that very few cheap routers or access points last more than a few months. I've never had one last for more than 18 months without constant nursing. They're OK out of the box, but develop problems as internal components start to fail. Buggy software doesn't help.

I've successfully done cost of ownership comparisons that seemed to help users understand the long-term expense. Because there's an understanding and acceptance of the limited life of consumer grade electronics, the get the picture quickly. And a couple of them have taken pride in owning a Cisco router or access point. They want it in plain sight rather than tucked away out of sight.

Haven't tried to sell new Cisco gear. Can't justify the payback. But then I've never been burned by defectve used Cisco equipment. I use the same set-up script for routers (got it off the net and refined it) so I don't have much variability in the base configuration. The rest of the set-up is from the web-based set-up tool.

I will admit that setting up a Cisco router takes longer than some of the plug 'n play stuff, but that is typically done once and then tweaked shortly after installation. For A/Ps, I've always just used the web-based tools. They work great and are easy to use.

Sounds like you cut a bad deal for yourself. I've been close to doing one of those support arrangements myself so I understand the risks. Too bad you didn't write in a clause for billing (even at a low rate) if the problem was not in the equipment you were contracted to support.

You could have been suckered into that one with a Trendnet wireless router.

I'm also close to retirement (2 1/2 weeks) so I'm interested in deinstalling the phone. ;) Except for a few friends. Maybe I can support them by phone from the Cook Islands. :)

Reply to
Cal Vanize

[...]

It looks like it was interference after all. I changed to channel

1, and the problem disappeared.

Thanks for your advice. Mike.

Reply to
Mike -- Email Ignored

On Tue, 13 Nov 2007 16:30:59 -0600, Cal Vanize wrote in :

Actually very simple and easy to use a digital timer on the power.

Doesn't age like that.

It actually lasts quite well, years in normal use, well beyond normal obsolescence.

I've got a great many running for years without incident.

Reply to
John Navas

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