Identifying the problem

[theanalyzer]

So my accommodation package gives me wifi internet only. There is one big router in the hall and many access points in the flats providing access to about 26 people and their devices. Everyone is supposed to get 8mb download speeds.

When its around evening time 17:00+, the internet becomes kinda slow, running a constant ping to google shows latencies of 3000ms+ (its usually 32ms). The problem lasts upto a minute or more and is random. Sometimes happens at other times of the day too.

If I ping my gateway IP (router), there is a lag is there too. The milliseconds usually compliment the pings at google.

It seems to me that the router is having load balancing issues. Have been bombarding the service provider with emails for about 2 months now.

Could a better router solve this problem? Or should I go just go and invest in a separate broadband line...(read that EE is providing 8mb/s at 6 GBP p.m)

[mikeo01]

When you say "Big router" be more specific, model etc?

Yes providing a better performing router would help as 26 people is quite a lot; depending on the router itself it sounds like it's having problems processing everyone's activity

That isn't a load balancing issue that just sounds like pure struggle on the router's behalf poor thing!

[CoolHotCold]

If it's a business class router it should be fine, if it's consumer based then 26 is really pushing it

[theanalyzer]

Oh, my bad. Its this one:

http://routerboard.com/RB1100AHx2

[watercooled]

If a load of clients are using WiFi on the same channel, that could cause latency problems too. Do you have the option to connect through a wired connection?

In theory a router like that should cope with 20-odd people fine, depending on how it's been set up. However, if it's just been chucked in with no proper configuration, then the lack of QoS queues could also cause major problems if someone is hogging all the available upload speed. There's a fairly long explanation as to why it happens, but it basically boils down to this:

The modem's buffer gets saturated with a load of packets by the router, but the modem has no understanding of the IP layer or prioritisation, so when someone starts maxing the upload, it just uploads them essentially in the order they arrive, and your latency sensitive packets, and TCP ACK packets get stuck in a queue while the modem is taking its time uploading tons of full packets. Decent QoS is essential for a situation like this, and will ensure a) the modem's buffer isn't allowed to fill and b) TCP-ACK and other latency-sensitive packets are given priority over bulk upload.

[theanalyzer]

How would I go about to convince the ISP people that the problem exists? I sent them pictures like this:



They think its because I have some trojan. If some trojan was uploading my data to someone, there would be more of "Request timed out" and the latencies would be fine (I tested with utorrent and max number of connections).

They sent a network intern, who sat and waited for 1 hour and it wasnt slow at all. Eventually he left. But he was convinced (the last time he came) that the problem existed, but prolly because he is an inter, he couldnt explain it.

[kalniel]

Switch to linux and keep requesting help. Linux isn't completely free of trojans, but the chances are so miniscule compared to windows that they shouldn't be able to fob that off as an excuse.

[watercooled]

If it's the problem I'm thinking, bad QoS, ping time to the router itself should be fine, which would also show your PC isn't to blame. Next time it happens, grab a similar screenshot but with a few pings to your default gateway.

However if that's also high, it could be a radio problem e.g. congestion/interference.

Edit: Durr! Just noticed you *do* have some router pings. Do you have a wired connection you could check, or another system to ping from?

[theanalyzer]

Nope, no wired system. But I do check from my Android ping apps sometimes, and pings are 4 digit there too at the same time its slow on the laptop.

Though one really weird thing. I had my system (PC) hooked up via the mobile (tether - 3rd type of connection in this scenario) and it was slow and at the same time my laptop was just fine. THAT could be attributed to mobile wireless being sucky though. I hate to write about this as it weakens my over all case that the router is the main problem.

[watercooled]

TBH the router is sounding less and less like the problem to me, unless it's being deliberately attacked somehow. Like I say it could be the wireless link getting saturated or suffering from some sort of interference, especially if everyone is using the same channel and sharing an access point or something - the theoretical transfer speed doesn't have to be met to start degrading wireless performance.

[theanalyzer]

Like I say it could be the wireless link getting saturated

How could that be resolved? From my side and/or their side. Switching channels? Like to 5Ghz or that n/b/g thing?

[watercooled]

Well installing wired connections to the rooms would probably be the best solution were it feasible. But yeah, spreading users over a couple of non-overlapping channels, and using multiple bands could significantly improve things. n/b/g/etc cover technologies, so for example b/g/n on 2.4GHz will still interfere/overlap.

It could also be interference; WiFi etc use essentially the same frequency band as things like microwave ovens (and tons of other wireless devices), so a leaking appliance could cause harmful interference when running.

[shaithis]

Get one of the wifi analysers...you can get them for windows and android.

Should show you the strength of your wifi and what others around you are using, might help pinpoint the problem to the wifi.

Also, what strength does windows show on your wifi connection when the slow pings happen?

[theanalyzer]

Get one of the wifi analysers...you can get them for windows

Well I decided to try one (inSSIDer and Chanalyzer). And there were interesting results. I was able to replicate the problem (high pings), but its not the exact replication.

Usually when it becomes congested/slow, the pings go 3-4 digits one after the other.

With inSSIDer or Chanalyzer running, the same problem happens, but the 4 digit pings come one after another like (1455ms, 5ms, 2045ms, request timed out,10ms etc)

Made a video to demonstrate the problem:



Wifi signals are full at all times. Checked pings on my mobile when running inSSIDer or Chanalyzer, and it didnt seem to be affected by my laptop's behaviour. So the problem seems to be with my wireless device....

But why and what would be causing such disruptions to my wifi? I really feel like installing/multi-booting Linux on testing.

There are also these settings in the Device properties of my wireless device (as i explore in the video):

Country Region: #0(1-11)
MM/Gaming Environment : OFF
Power Saving Mode : CAM (constantly awake blabla)
Radio ON/OFF: Enable
Roaming Sensitivity : Medium

Any idea if the bold ones could fix it? Ive been reading about someone fixing their dropping connection problem updating drivers and setting sensitivity to high (but then their problem is dropping connections, mine isnt)

Gotta to test that for myself, at the moment, I made the sensitivity HIGH and Gaming environment to ON, inSSIDer still causes high pings. Have to see results over the next day or so, if pings go bad.

[watercooled]

The change caused by having inssider open would suggest a local issue rather than with the network, and could be unrelated. However, it could also suggest a driver issue (are NIC drivers up to date) or CPU load (is CPU heavily loaded when ping spikes?)

There are an awful lot of stations nearby by the looks of it. Although your network has a decent signal strength vs the rest, they can still interfere and reduce throughput - stations operating on the same channel will still 'hear' stations from other networks, sharing the channel - that's only filtered out at higher layers.

I'm not too sure what mm/gaming environment would do, maybe some form of better tailored local QoS, which I doubt would help here.
Radio on/off does what it says - it will switch the WiFi radio on/off.
Roaming sensitivity refers to how aggressively the client will switch between different APs on the same network, based on signal strength. Not really relevant here.

However, driver strangeness means some settings can have an impact on seemingly unrelated issues.

Next time you get the major latency issue, see if it persists with nothing else running.

[theanalyzer]

Well the chip is RT3090 from Ralink (now merged with MediaTek). Got the drivers from here:

http://www.mediatek.com/_en/07_downloads/01_windows.php

Changed to those settings. Again at around 1700 in the evening the random lag started. Everyday, I can play dota like right uptil 1630-1700, after that its risky to play. The video I posted does seem laggy, and my it indeed was (cpu load). But the tests that I do (like the previously posted picture) is when the CPU is idle, so cant be it or a simple prime95 would be able to reproduce the problem.

So back to square one.