Diagnosing and what to do about poor internet connection (likely wireless signal)

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DaRuSsIaMaN

[H]ard|Gawd
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Apr 22, 2007
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I need to figure out the reason(s) behind, and what to do about, my poor internet connection. It's very inconsistent. It can be pretty adequate at times, and at other times it's really laggy. I am in a 3-story house in Boston. The modem/router (both in 1 device) is in the common room on the second floor. I'm relying on the wireless, since winding a cable down the stairs and across the hallway would be very unwieldy.

**********************

So, first problem: I don't understand this situation.

If the problem is simply poor wireless signal strength, then why is my internet connectivity not consistently bad? It's only bad sometimes. Or much of the time. But the point is, it's not always good, it's not always mediocre, it's not always bad. It varies between bad and mediocre and sometimes *really* bad. Why would it vary? Is it possible for a router to output poor signal sometimes, mediocre signal sometimes and good signal sometimes? Doesn't it always transmit the same quality signal??

Secondly, still with first problem, why does Windows tell me that the signal strength is fine? The quality of my experience appears to be completely (or maybe just mostly) decoupled/not correlated with how many bars I see in the task tray. It seems that sometimes I see 4 bars and yet websites grind to a halt. Other times I see 2 bars yet browsing is fine. Wtf?

I think my roommates on the second floor do not experience any issues. I haven't asked the other one yet.

***

Now, second problem: what do I do about this?

Just get a second router with powerful antennas and set up some kind of repeater thing? I feel like I should find out more about what's going on before I start spending money and -- more importantly -- time that I should be spending on grad school instead of dealing with this crap.


Thanks for any help.
 
Interference can give you a false sense that everything is perfect. Most likely there are many people in the area who are using wireless device, or even the same provider with modem/wireless router combo where it's left on the default Wireless Channel.

I'd suggest using inSSIDer to determine the relative signals in your immediate region and try to move to a channel that has less interference. Of course distance wont help much either if it's interference from neighboring wireless devices, which can also cause the instability sometimes and not in others. I'd try that and go from there.
 
Yes, use inSSIDer to see what channels your neighbors are using. If you're using Wireless G (the 2.4GHz channels), many wireless routers are defaulted to channel 6. To avoid interference from other people using channel 6, you should choose either channel 1 or channel 11, because when you use a channel, you also use the channel above and below the one you chose, and cause interference in the two channels above and the two channels below the one you chose. You'll see how that works in the inSSIDer display. Don't choose channels between 1, 6 and 11; you'll just get interference from two of those channels instead of just one and muck it up for everyone else in both of those channels.

Going to Wireless N and using the 5GHz channels eliminates all that; there's a lot more channels to choose from, and you aren't getting interfered with by microwave ovens, garage door openers, and whatever else uses the very popular 2.4GHz bandwidth. It is more expensive, though.
 
Liger88 said:
Interference
Click to expand...

Ahhhh I can't believe I completely forgot all about it!

Ok so here is a snapshot of what I see on inSSIDer. When I click on the RSSI header to arrange it by descending RSSI, it fluctuates a lot. So is just one of those instances. But my own network is highlighted. Interestingly, it's on channel 9. I guess that was how it was set up? So should I switch it to channel 6 instead? There's seems to be only 1 channel 6 network nearby (most of the time). When I watch it fluctuate for a bit, it seems that the top few networks are channels 1, 11+7, 3+7. Also I see an 8 and a 6 pop up. Suggestions?

 
First piece of advice.....get your channel width out of 40Mhz mode and down to 20Mhz mode.

That should help. Currently your wireless router is trying to go for the gold and in that environment (seen on inSSIDer) it isn't going to happen.

That is step one.


Step two is....see if this is any better.
Force your unit to channel 11. Your 8db stronger on your signal than the next closest signal. You may be able to talk over their network.




Step three....admit defeat 2.4Ghz is way crowded at your location. You need to either use 5Ghz or give up using wireless and use Powerline/physical ethernet instead.


If it were me, I would try to get everyone together and see if I can offer my services to improve everyone's performance/compatibility and speed. By smartly using the correct channels and turning down the damn output power. IF that didn't work I would probably make a point by using a 2.4-2.5Ghz noise generator for a week. :D ....and then again offer my services.
 
Click the tab for "2.4GHz Channels" and that will make things more clear. You have a LOT of neighbors because I count at least 14 unique SSIDs there and you haven't scrolled down to see the others. No wonder you're having trouble. Like Mackintire said, the only real solution is to get out of the 2.4GHz channels entirely. The ones with generic names who have left their security open - if you try to talk to them about it, they'll have no idea what the hell you're talking about.

Wireless N is able to use both 5GHz and 2.4GHz, while Wireless G can only use 2.4GHz. The 11+7 and 1+5 stuff is Wireless N routers being able to use two G channels instead of just one when connecting to G NICs. The 11 is the primary and the 7 is the secondary, or the 1 is primary and the 5 is secondary. In this case, it's like being in a noisy restaurant and someone starts shouting so they can be heard over everybody else; in the end, everybody's shouting and nobody can hear anything.
 
Thanks for the help so far, guys. A few things. First, I did a little digging about my router/modem, which was provided by the ISP. It turns out it's an N-capable router... It's an SMC SMCD3GNV. (Also, wiki link.)

Interesting. However, I cannot make it go into the 5 GHz band/mode. Can't figure out how. Nor can I change my channel width, as Mackintire suggested. The control panel or interface, or whatever you call it, is very basic. I have little experience with networking but in my limited judgement this looks retarded rudimentary. The below screenshot is pretty much all I can control:



There's nothing about channel width, and there's nothing about selecting the 5 GHz instead of 2.4 GHz. I can switch to manual channel selection, in which case it only lets me select 1, 6, 11. Ok fine. So I can try going with channel 11. But what if I want to select two g channels, <x> + <y>, like some of those other networks are doing? Apparently I can't manually do that either. If I select channel 1 or 6, it assigns a second one. For instance when I selected channel 1, it showed up as 1 + 5. Selecting 6 made it do 6 + 10. When I put it to 11, it shows up as only 11 in inSSIDer.

*****

If I switch to automatic, it randomly selects 2 channels. I don't even know how it used to be on just channel 9 previously. Because after playing around with it and switching back to auto, it's now set to 10 + 6. If I switch back and forth between manual and auto, I can get it to be on a different channel combination, but it's random, like throwing dice.

*****

So anyway, I think my signal situation did improve. It's not a catastrophe anymore. I can rely on it to actually be able to do work without interruption. But I still want to do more. Why am I not able to switch it into 5 GHz mode??

Can I maybe upload some 3rd party firmware to this thing which will have more options? Looks like DD-WRT does not support anything by SMC at all. :\
 
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Have you tried hardwiring into router and see if wireless is even the issue or if the connection just sucks?
 
marley1 said:
Have you tried hardwiring into router and see if wireless is even the issue or if the connection just sucks?
Click to expand...

No I have not myself. But the connection sucking is not it because one of my roommates is wired to it, and he reports that he has no problems. The other guy who is on wireless but much closer to it than I am also has no problems, I believe, although I haven't talked to him about it much.
 
jimh425 said:
I'd also switch to aes mode.
Click to expand...

Oh, why? I pretty much have no clue about what the differences between tkip/aes, etc. modes are, aside from that WEP is easy to break into compared to WPA. What does AES mode do better?
 
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Try ....that wireless N devices are built for WPA2-AES encryption and other encryption methods are not only harder on the device but less secure.

There's discussion on the comcast forum about how crappy the vender was with this device and how it creates interference and results in a hostile 2.4Ghz wireless environment.


Based on what I see you're best off reconfiguring the SMCD3GNV into bridge mode and but a real wireless router that you can actually control.

Once you have a real router Comcast can put your SMCD3GNV into bridge mode for you Call this specific support number for assistance 1-800-363-2416.



You have zero chance of using two channels in the 2.4Ghz spectrum at your location without severe performance problems.

I would suggest you heed the advice we are giving you.

New router:
Channel 11, 20Mhz mode. set to wireless N only, WPA2-AES
You should see close to 10MB/s over the wireless after doing this.
 
Mackintire said:
There's discussion on the comcast forum about how crappy the vender was with this device and how it creates interference and results in a hostile 2.4Ghz wireless environment.
Click to expand...

Ahh now that you mention it, I looked for this specifically, and I'm indeed finding multiple threads of people having issues with this device. I didn't see it before. People are suggesting basically the same thing you are. For instance:

wireless gateways are generally terrible devices, with their biggest weakness in their router functionality.

The allure is that all the functions are built into one box, but the fact is that few if any gateways do a very good job.
Click to expand...

...etc. Well, that settles it. I will get a decent router and have the gateway put in bridge mode, and put the router into N only mode.

Mackintire said:
I would suggest you heed the advice we are giving you.
Click to expand...

Absolutely! lol. Your advice is greatly appreciated, and I'm going through with it. Thanks! :D
 
Would something like this be okay?
Buffalo WHR-HP-G300N
Just one that happens to be on sale for $40 in the promo email. Comes with DD-WRT so that's nice.

However, question: why does it not list anything about a 5 GHz band? If it can do IEEE 802.11n, and all n-capable routers can do 5 GHz, why does it not say anything about it? I just want to double check... like I said I'm no expert on networking by a long shot.
 
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