Why is my wireless network so SLOW?

B

baggss

Stoopid American Rednek
Ok, I have 3 Macs (a G4 tower, and iBook and an iMc) and a PC all hooked wirelessly together via Airport. This is not an Airport Extreme, but a regular Airport. 2 of the Macs have Airport cards, the iBook has an extreme card and the PC has a Linksys USB wireless box. Internet speed is fine on all of them, it is when I transfer data between them, that it is VERY slow. I moved 70Mb of files from the tower to the iBook and it took 15Min to transfer. The same was true between the G4 and the PC.

All 3 Macs are running 10.3.4 and the PC is running XP SP1...

Anyone?
 
Wireless is notoriously slow for large data transfers. Anything over, say, 20MB and you should just use a direct ethernet crossover cable (or connect your computers through the linksys) because you will be waiting forever otherwise. Just the way the wireless cookie crumbles.

The Wireless G standard is much faster than B (regular airport is B, extreme is G).
 
So what you are saying is if I upgraded to an Airport extreme, this whole process might speed up. Ok, I can live with that. Just seems odd that the whole thing is fast when connected to the internet via Airport, but slow computer to computer.

Oh well....

Thanks for the help....
 
Why does this happen when transfering a 20 MB file? 20 * 8 = 160 Mbits of data. Airport has a speed of 11 Mbits/s. That should in theory take only 15 seconds to transfer the data.

Something must be wrong if the speed drops like that. But then, I don't use wireless networks, so I'm just guessing but I see no reason why it should be slow.
 
Connections to the internet are likely using a simple protocol like ftp or http - there's not much transferred at all, other than the file you want. So moving around a 20 MB file might involve something around 20.5 - 21MB of total traffic.

AFP and SMB file sharing are both extremely chatty protocols - especially SMB - so there's much more traffic than just the size of the file. Just clicking on a file on a Windows share (not even opening it, just selecting it) generates a couple hundred K of traffic. Transferring a 20 MB file will involve a lot more than 20 MB of traffic. Don't know how much exactly, but a lot; you're seeing that inefficiency magnified by the fact that it's also happening over wireless.

Switching to a faster wireless protocol will speed things up, but I wonder how much, compared to switching to wired networking. Wireless networks, no matter how fast they are, always suffer from some inefficiency that you don't get with switched ethernet - you can't have full duplex transmissions, much less two simultaneous transfers at full speed, since the whole thing is one collision domain.
 
WiFi throughput is similar to that of a hubbed network in that it is a shared medium. For example: Say you have an 8 port 100 Mb hub, and you have 4 computers connected to that hub. What you have done is basically divided that 100 Mb bandwidth amongst the 4 computers, meaning that you have 25 Mbps per machine. Mind you, this is not a constant since not all machines are accessing data from the network/internetwork at the same time. However, you can test by connecting one machine on a hub and streaming music like through iTunes, and then doing it with all 4 machines connected and see if anything happens. Most likely, the more machines you have connected to the hub, the greater possibility of having collisions because of the nature of Ethernet.

WiFi is a little worse when it comes to speed. 802.11b is 11 Mbps and it's shared like an Ethernet connection on a hub. However, instead of being a bit variable as on wired ethernet, each machine reduces the throughput by half EVEN IF IT'S ONLY ASSOCIATED AND NOT ACCESSING DATA. Aside from that, your throughput reduces as you get farther away if your throughput is set to auto. You can force the bandwidth to be 11 Mbps for evey host, but it effectively reduces the distance you can travel.

802.11g is much faster and backwards compatible, but it's drawback can be said that it IS backwards compatible. If you have a bunch of machines using G and one machine comes in with a B connection (and this feature hasn't been disabled on the AP), ALL MACHINES ASSOCIATED drop down to 802.11b.

The moral here?? You connection is only as fast as your slowest link. Also, if you have the AP set to auto for bandwidth, you are at the mercy of the machine with the slowest connection. Another example: If you have all the machines at the radius for 11 Mbps, and another machine associates from a distance where only 2 Mbps is available, ALL MACHINES NO MATTER WHAT THEIR DISTANCE FROM THE ACCESS POINT are going to associate at 2 Mbps max.

Also, make sure that other devices that might interfere with the signal, such as microwave ovens and wireless phones in the same 2.4 Ghz spectrum, are not doing so. I have found out that channel 11 has given me the best signal when encountering interference from other devices, but YMMV.
 
Hey, thanks for all the info guys. It appears that upgrading to AP Extreme won't help much unless I put extreme cards in the G4 Tower and G4 iMac and upgrade the PCs wireless box to match. With as little as I do this, it doesn't seem like it's worth the effort right now. At least now I know why it's slow and that it's not just me.

Thanks again...!
 
Great info on wireless stuff.
I was thinking of getting an airport base station but now that transfer rates
are slow (even with extreme), I'm not so sure.

Can I somehow still use airport just for internet and at the same time
use my exixting 100baseT LAN for file transfer? or is this impossible?
I have a Powerbook, a G5 and 2 PC workstations and I transfer a lot of files
between computers - Rendered animation, DV movie data, 3D files etc and file size
range from 200mb right up to 2GB. all are connected to a switch.

I already have a wireless dsl connection and the modem needs to be placed near a
window to get the best signal from the isp. my work area is 15 feet away from the window. right now a long ethernet cable connects the router to the modem so I thought airport would be a good idea and then I can move my powerbook around.

thanks
 
I would think you could use both. You would just have to change configurations in the Network control panel from AirPort to Ethernet depending on what you want to use.
 
Ok, so I can keep the airport and my local LAN seperate. If I open safari
it will use the airport to get online and If want to transfer files it would use
my local LAN. I must be sure before I fork out money for the airport base station
thanks
 
why airport base station? Go for a cheap wireless router such as netgear or dlink. And yes, your mac can deal with 2 connections at the same time: wan and lan. Everything within the subnet will be redirected to the lan and everything else to the wan. But since you want to go for a router anyway, why not let the router deal with it?
 
Hi Zammy-Sam, u haven't been online for a while. I'd like to have just the wireless router handle both the LAN and the WAN but after reading this thread I found out that wireless 802.11 is not as fast for file transfers( local LAN), so I thought one way was to have both the wireless and the hard wired LAN coexist so I can have the best of both worlds. I can then move my powerbook around and later another person in the house is getting an ibook, and having wireless will save me the hassle of more wires and cables
So you think I should save some cash and get non apple wireless routers, I'll google
for prices on the netgear one since I already have a netgear switch
thanks
 
Instead of wireless hubs, will the situation improve if you use wireless switches? I know that switches don't suffer from the problem often associated with hubs.
 
Hey Ailes. I think, if you are going to plug your powerbook anyway (since you want to have a fast filetransfer), it still would be a better idea to let your router deal with the wan and lan. Why? I mean, if you are going to have the powerbook wired, you could not just let your internet connection go through the ethernet cable, but also your lan transfers. If you then decide to be wireless, you simply unplug the ethernet cable and your wireless connection will be used for all transfers. In other words: get yourself a cheap dlink or netgear wireless lan router and let the router do it's job. When you transfer large files, you simply plug the ethernet and have 100mbit. And if you just need to browse in the garden and don't want to have the fast lan-cable plugged, simply unplug and without adjusting anything, your mac will redirect all traffic to the airport. You will have a good coexistence between wired and airport connection and don't need to have your powerbook always on, when another computers want to get online..
 
Oh! well, I think I'll leave things as it is for now, since I need the faster
file transfer more than a wireless LAN, and I "forgot" that I also have 2
Linux workstation to deal with if I decide to go wireless.

Thanks for all the suggestions and help
 
Viro - I don't think a wireless switch would be possible. Switches isolate bits of wire from each other by physically opening and closing switches internally. You can't isolate bits of air from each other, since everyone's transmitting in the same bandwidth.
 
scruffy said:
Viro - I don't think a wireless switch would be possible. Switches isolate bits of wire from each other by physically opening and closing switches internally. You can't isolate bits of air from each other, since everyone's transmitting in the same bandwidth.
Click to expand...

Actually, I have heard talk of Cisco working on creating something along the lines of a wireless switch. Don't ask me about the details as I have NO idea how they are making this possible. It could all still be concept work on their hardware, but who knows. I would LOVE to learn how they are able to achieve this if this is true. :)
 
For what it is worth, I just read somewhere that Airport really only achieves about 6 mbp's.

Rather than write a new thread I wanted to add a related question here. Our old iMac g3 500 mhz just got an Aiport card and very often the connection is dog sloooooow - to the web, iTunes music store, even checking email. Connection signal is strong, and a PC with a 802.11b card using the same router is always zooming along as does another Mac hooked up via ethernet. Any ideas please?
 
You must log in or register to reply here.
Back
Top