networking - analyizing why wifi / internet connection is slow

07
2014-07

sam

We've got around 10mb download internet which we connect to over wifi, we have about 8 machines / devices connected at any one time. The internet speed ranges from ok to bad depending when you use it.

Is there a way i can see all the traffic over our wifi network and analyize whats slowing it down ?

I know i could go through each machine disconnect it, monitor and try and trouble shoot the issue that way, but its unscientific - is there a better way ?

Answers

Nevin Williams

I think studying each component of a system to determine why it may be behaving in a certain way is the epitome of scientific; perhaps you intended 'technical'...

To examine an access point's or router's packet counters and stats, I suggest investigating [SNMP]. If your router/wifi AP supports it, it can provide an abundant account of interface attributes to assist in diagnosing a problem.1

Are all hosts connecting with 802.11n (or better), or is there a mixture? If you've no .11g devices, setting your wifi AP to exclude .11a/b/g will improve performance. There are a plethora of online WiFi tuning articles to be found to suit the spectrum of network configurations.

In this case, though, as stated, it's not clear if there is a wifi issue. This should be verified by transferring data between two hosts, and noting its characteristics: transfer rates, error rates, hangs, signal levels.

Concurrently, when experiencing performance degradation, verify that a wired host has good connectivity, which will also help identify whether WiFi is an issue.

Related Answers

dlamblin

Because it's not a big truck.
It's a series of tubes.

And with wifi, there's not even tubes in the series.

Seriously, your problem could be any of the following, and we need more info about your router, about how all the computers connect, about all the computer specs and amount of use, and about what you did when you changed from one laptop to an other with "the same problem."

Lets assume all the computers are on the same wireless connection. If the old and new laptops are 802.11b while the other computers are 802.11g that's a simple explanation. Even if it were reversed, it might explain it, because b has a little more range than g and maybe you're using the old and new laptops a tad far from the router.

Otherwise the old and new laptops could be always in the same location. There could be interference just there. Maybe from another appliance, or some wiring in the wall to that room. Common culprits are: Microwaves, Compressors (in an Air Conditioner or Refrigerator), fans (in anything from an air-filter, to a plasma TV), paper shredders, electric water boilers and in-sink garbage disposals.

It could be the OS or software. You might have replicated the same software to the new machine and been stuck with the same problem. E.G. I've found some virus scanners to run so frequently (daily) for so long (4 hours) while thrashing the disk so much, that general downloading that gets cached to disk or saved is definitely 1/4 regular speed.

Or it could be that all your computers are not treated equally by the router. It might be doing Quality of Service filtering, or it might be lacking proper QoS. In one case it might think that computer is low priority, or in the other case it should be throttling the up-streams of the other machines so that they allow ACK packets through uncontested.

Rob

What kind of router? Wireless B routers have had problems with Vista.

Any security suites running? Mcafee/etc can definitely slow down your connection.

Is this a WAN only problem, ie, can you copy files to/from other computers on your LAN without any problems?

If possible I'd try a speed test on both the vista laptop and a non-vista laptop and see how they compare.

Assuming a reasonably powerful computer ram/processor wise Vista shouldn't really be much slower than XP.

Yuval

Just in case you have a bandwidth-hungry process on your laptop, try NetLimiter or some similar application. It's a sort of task manager for bandwidth usage, and not only will it give you a clearer picture of bandwidth usage, it will also allow you to limit this usage per process.

splattne

I've never had these problems with Vista machines on my home network/Wifi. Has this computer a special configuration, is it perhaps connected to a VPN and all the traffic is routed through the VPN? Normally you can change this behaviour in the VPN network settings.

Since it happens on a new computer, I suspect a configuration problem or a problem with the wifi access point/router. You could try to upgrade your router's firmware (disclaimer: careful, when you do that - you could end with a bricked device, bla bla...)

Tim Meers

Because you did not say if you'd tried attaching it to the wired network or other troubleshooting this is kind of a long shot. But as far as I'm aware there is Auto-Tuning on the network devices. Here is a nice write up on how to disable this. After running only internet speeds and not doing a lot of internal traffic the overall network speeds were down to below what my DSL speeds were after about a week of using my Vista laptop. Once completed my intranet and internet speeds were were back up to snuff.

You may also want to check for newly installed software like firewalls and anti-virus. As already stated these can wreak havoc on your PC speeds.

Also it should be noted that despite your wireless potocol A, B, G, N, all of them are going to be much faster than your typical home internet connection. Granted, if your hardly able to get a network conection due to being 100's of feet away you will have slowness but that does nto appear to be the case.

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networking - analyizing why wifi / internet connection is slow