Help with Wireless card (TP-Link)

[Dragice]

You'll have to forgive me, I'm pretty new to the desktop world so I'm probably missing something obvious.
Anyway, I'll get to the point. I recently got a new desktop from PCS with a TP-Link TL-WN881ND 300Mbps wifi card. I get "up to 100Mbps" from my ISP, but I rarely get above 80 on any device. My problem however, is that on the desktop I never get about about 30 Mbps. I know it's not the connection, because putting a laptop I got from PCS next to the desktop the laptop gets 83 or so. I've seen on forums and such that other people have similar problems with other models, but they get all technical really quickly and I get lost. I was hoping some of you nice people could help explain to me what to do in words I understand (or at least don't have to google every 3rd word).
I've got the drivers up to date, and I've tried resetting everything, used both the TP network configuration and Windows, and most importantly swore a lot. It's not urgent, because 30 is still pretty dang fast, but I just want to know what I'm doing wrong, or if my house just hates me.
Thanks for your help.

Edit: If it's any help, it's the one on the site called "WIRELESS 802.11N 300Mbps PCI-E CARD"

 

[ubuysa]

Hi Dragice, I'll try and keep this as non-technical as possible.

You have the drivers up to date I see which is good, because that's often a cause of these sorts of issues. Clearly something is creating a bottleneck between your router and your PC which is reducing the maximum data rate from 80Mbps down to 30Mbps (oh, how I wish I could get 30Mbps here ). It could be because of a less than perfect radio signal between you and the router that causes many of your data packets to have to be retransmitted several times (in either or both direction) and the effect of these retransmissions is to reduce your apparent bandwidth.

So, we need to see how many data packets are being retransmitted and we can get at that information by issuing a simple Windows command. To issue this command you need to open the Command Prompt window.

On Windows 7, you need to click Start then click All programs, from the list of programs click on Accessories and from the list that drops down click on Command Prompt. The Command Prompt window will open, it's black with a simple C:\Users\your-name> prompt.

On Windows 8, you need to click Start then click All programs, from the list of programs click on Windows System and from the list that drops down click on Command Prompt. The Command Prompt window will open, it's black with a simple C:\Users\your-name> prompt.

Now simply type "netstat -s" but without the quotes ("). Note that there is a space between the netstat command and the -s parameter. This command requests a list of all the network statistics, it's a long list and you'll need to use the scroll bar on the right to scroll back and forth through it.

For now, the information we want is at the bottom. Find a group of statistics labelled TCP Statistics for IPv4, tell me the following numbers:

Reset Connections
Segments Received
Segments Sent
Segments Retransmitted

The group underneath labelled TCP Statistics for IPv6 should have very low numbers in it (less than 10 for each). If any of the numbers are more than 10 give me the numbers for the same rows as IPv4.

Now find the group of statistics labelled UDP Statistics for IPv4, tell me the following numbers:

Datagrams Received
Receive Errors
Datagrams Sent

The group underneath is labelled UDP Statistics for IPv6, if any of the numbers in there are more than 10 give me the same numbers as for IPv4.

This will give us a feel for how many data packets are being retransmitted and will confirm or refute my hypothesis that it's a poor radio connection.

Don't be afraid to ask if you don't understand any of these instructions.

 

[Dragice]

Right, the IPv4 stuff is
Reset Connections: 220
Segments Received: 1796400
Segments Sent: 848530
Segments Retransmitted: 7900
Datagrams Received: 843626
Receive Errors: 307649
Datagrams Sent: 843679

IPv6:
Reset Connections: 43
Segments Received: 115689
Segments Sent: 58642
Segments Retransmitted: 305
Datagrams Received: 214084
Receive Errors: 0
Datagrams Sent: 226481

Since you said IPv6 should be less than 10, is it bad that it's so high? I'm usually pretty tech savvy but this is an area I know nothing about.

 

[ubuysa]

I only said IPv6 might be less than 10 because IPv6 is rarely used in the home environment at the moment, IPv4 is the dominant protocol at home. Windows can (and does) use IPv6 which is why you see some IPv6 traffic, it may be that you also have some applications using IPv6. Either way, it's not something you ever need to worry about, it's all under the hood stuff.

The TCP numbers are not bad but still a little higher than I'd expect. For both IPv4 and IPv6 less than 1% of segments sent need retransmitting, so not too bad but not zero.

The UDP numbers are a lot worse because there is no error recovery for UDP as there is with TCP, IPv6 is perfect (0 errors) but IPv4 shows 30% receive errors which even for UDP is a little on the high side.

So whilst these numbers don't indicate that a poor radio signal is your problem it's worth investigating further because you are getting transmission errors and a poor radio signal is the commonest cause of low bandwidth. Often this is caused by interference between local hotspots, your PC's wifi adapter might simply be more sensitive to this interference than your laptop's wifi adapter.

I'm going to suggest you download and install a free software program called inSSIDer. This will display all of the local hotspots your wifi adapter can see, which channels they are using and, for your own hotspot it will show whether it is subject to interference from nearby hotspots. So download inSSIDer from http://www.metageek.net/support/downloads/ and install it just like you'd install any other program.

When you start inSSIDer you'll see two tabs right at the top labelled Learn and Networks, the Learn tab is very useful because it tells you how to use inSSIDer, what it does and how to interpret the results. For now though click the Networks tab.

You'll see four small windows. The top left window is showing information about all the local hotspots your wifi adapter can see, the hotspot you are connected to is at the top (with a blue star). The key number here is Signal, it will always be a negative number and the smaller the number the stronger the signal (so -32 is a stronger signal than -69). The list is ordered in decreasing signal strength.

The bottom left window is a graph of the signal strength of all the local hotspots, the hotspot you are connected to is shown in blue. If you click on any other hotspot in the top left window it will be highlighted in the bottom left in yellow. In the bottom left window you can see which channel the clicked hotspot is using (there are 13 available channels in Europe) as well as the channel your hotspot is using. You will probably be either channel 1, 6 or 11 and you'll see many other hotspots also using those same channels. The more hotspots sharing the same channel the greater the risk of interference and bandwidth problems.

The top right window shows detailed signal information for the hotspot you are connected to. The text tells you the number of co-channels (those hotspots using the same channel as you) and the number of overlapping channels (those channels whose radio transmissions overlap your channel to a greater or lesser extent). The blue line is a graph of the signal strength from your hotspot, the red line is the signal strength of the strongest hotspot either sharing the same channel or overlapping your channel. The closer the red line is to the blue line the greater the risk of interference. You can also click on any of the hotspots in the top left window to display their signal as a yellow line for comparison with the signal strength of your hotspot (blue line). You should watch this graph for a while (it updates regularly as you can see) to be sure that your hotspot's signal strength stays constant and the graph of the strongest hotspot sharing the same channel does not come near your signal level at any time.

The window at bottom right you can ignore.

Now, the larger the number of co-channel networks in the top right window, the greater the risk of a problem. This is because all those hotspots have to queue up to use that channel and this can reduce apparent bandwidth.

Also, the larger the number of overlapping networks the greater the problem. This is because these adjacent signals can mask your own signals or corrupt them enough so the hotspot has to retransmit.

In an ideal world we'd want 0 co-channels and 0 overlapping channels. In the real world that's not possible. So if, as is likely, you have a lot of co-channel networks (many sharing the same channel as you) you might get better performance and increased bandwidth by switching your router to a different channel. Pick one that's not used by any other hotspot. Channels 3,4 8, and 9 are usually good choices, pick one that nobody else is using. This will likely increase the number of overlapping channels but that's generally less of a problem. To change channels you need to change the router configuration. When you first set the router up you'll have had to do some basic configuration (setting a name for the hotspot for example and the password you need to use to connect) and the channel used by the router is in that config setup somewhere. Changing the channel will have no effect on any devices using the hotspot, they will have to disconnect and reconnect when you change channels, but other than that they will notice no difference.

So let me know how you get on with inSSIDer, how many co-channels and overlapping channels do you currently have for example?

At the end of the day, you might just be unlucky. WiFi radio is also subject to all sorts of other interference too and it might never be possible to get more than 30Mbps from this adapter in this location. So as alternatives you might want to get an Ethernet patch cable and connect your PC directly to the router with that. Your ability to do this depends on the locations of the router and your PC. Another possibility is to get a set of homeplugs, these effectively turn your mains electricity wiring into an Ethernet cable. Both these techniques will give you error free communication with your router and maximum bandwidth. It might be easier to go down that route than spend time and effort troubleshooting your wifi adapter?

Sorry this is so long but you did say you weren't that technical.

 

[Dragice]

I think I'm gonna have to go with the alternative method, since inSSIDer tells me there's 0 co-channels. There's only 1 other network in the area, and I'm on channel 6, that one's on 11. Oh well, thanks for all your assistance anyway.

 

[ubuysa]

I think I'm gonna have to go with the alternative method, since inSSIDer tells me there's 0 co-channels. There's only 1 other network in the area, and I'm on channel 6, that one's on 11. Oh well, thanks for all your assistance anyway.

That's unusual. I have no idea where you live but it must be pretty rural to be able to see only one other hotpsot? That said, I think a direct connection is your best option. You can spend days chasing these elusive wifi issues round and round and for a PC that makes no sense if you can arrange a direct Ethernet connection or homeplugs.

Let us know how you get on.

 

[Dragice]

Yeah when I move the desktop down to the router and ethernet it it gets 80. Guess I gotta get me a homeplug. I'm also not in a rural area, the houses are just pretty well spaced.

 

[ubuysa]

Yeah when I move the desktop down to the router and ethernet it it gets 80. Guess I gotta get me a homeplug. I'm also not in a rural area, the houses are just pretty well spaced.

So you're rich then?

Well done, so it's a radio problem you're having. They're very common. I live on a yacht , most of the winter we're in a marina. I spend a huge amount of my time helping other yachties with wifi problems. A marina, with all those metal yacht masts, booms and hulls, is not a good place for wifi.

Homeplugs is the answer.