Multiple AirPort Expresses: huge impact on wireless speeds

[Bengt77]

Hi all,

I have a problem for which I just can't seem to find a solution. At one moment during the past week, my internet connection got extremely slow. I thought it was because our ADSL modem was acting up, so I restarted it several times. That didn't help at all. I didn't really need a fast connection until today, so I started digging to see if I could find where the problem was. Well, it turns out it's with the AirPort Express base station. Base stations, actually, as I have three. I couldn't get a good reception in the back of our house, so I bought a second that's used in the living room, which I now have connected to my stereo. AirTunes is very nice, as I found out. I also wanted to connect a printer wirelessly, so I bought a third AirPort Express to go in the back of the house (as that's where I put the printer). That should also sort things out concerning the bad reception in the back of the house and in the garden.

However, connecting to the third AirPort Express proved difficult. Sometimes it shows a 0% signal strength, when checking the signals using AirRadar. Very weird, as I have the two extra base stations set up to extend the signal of the first (which is of course set up to allow for signal extension). Well, today I finally decided it would be easier to just walk over to the back room and momentarily connect the printer to the MacBook when in need of printing. Yes, I could place the printer in the living room, but I don't want to put such an ugly device in plain sight.

Okay, and now for the real fun. Last week I thought it would be cool to check how fast my internet connection really was, using Speedtest.net. It turned out to be roughly 10Mbps. Quite okay, I guess. Well, today I checked it again to see if the connection really was as slow as I perceived it to be. And yes, it's 1,5Mbps right now. A quick check with a direct ethernet connection from my ADSL modem to my MacBook showed that the actual connection was still 10Mbps. So, then the quest for a solution began. I had the AirPort Express base stations connected to each other via a WDS setup. Extensive searching taught me that WDS can severely slow down a wireless network and negatively effect the wireless range.

So, I decided to try turning WDS off and set up the base stations as one main station and two signal extenders. That didn't help one bit. I then learned that AirTunes can also seriously impact wireless speeds. But turning off AirTunes on the two AirPort Express base stations that had the feature turned on, did nothing. Then I started to get worried. Some AirPort Express restarts didn't help, either. Even restarting my MacBook multiple times didn't work.

Using AirRadar, I checked to see if the wireless channel I was using wasn't too crowded. There were two other networks using it, so I switched to one nobody else in the neighbourhood was using. That did nothing, either. Even lowering or increasing the multicast rate did nothing positive. And that was the very last thing I could think of that might help.

So now I'm sitting here with no ideas left how to solve this problem. If anybody has one, please help me. I really want my connection back. So please, please help me. I'm not one to give up easily, but I'm really out of clues here. Thanks in advance.


-- Bengt77


EDIT: Switching off the two extra base stations, turning off WDS on the main one and restarting both the main AirPort Express and the ADSL modem is something I only just thought of, and guess what? It did the trick. My true internet speed is back: 10Mbps. But one huge question mark remains: why does the speed go down so drastically when using multiple AirPort Expresses? And AirTunes? Does anybody here have a clue, because I would really like to have an answer to that question.

 

[waw74]

airtunes will only slow you down if you are currently using it, since it takes some of your available bandwidth. Shouldn't make the base slow down if it's enabled, but not in use.

Like you said WDS will slow down your connection, as will extending, basically each jump it makes cuts your speed in half (half of the bandwidth in, half out), so after 2 jumps you're at 1/4 of the original speed.

The 10Mbps, is the speed of the port, not the connection. You'll see network gear advertised as 10/100, which is either 10Mbps or 100Mbps (also gigabit 1,000 Mbps is another option). You need to run speed test when wired, and not just look at the connection speed that is reported by your network card. A quick look online, and the highest speed i could find advertised by DSL is 3Mbps, and I doubt even with that service, you'd actually see that speed on a consistent basis.

If you have the option to hardwire the remote expresses, I would do that. although that will become problematic if you are using the express as your main router (connected directly to your modem) since it only has 1 ethernet port.
I would recommend getting a router that also has multiple ports(dlink, linksys, airport extreme, or other). you don't even have to get one with wireless, since you already have that with all your expresses. Then set up all the expresses exactly the same (SSID and security settings), except for different channels. You also want set under wireless "create a wireless network" and under internet "connection sharing" to "off (bridge mode)". that will then make the wireless networks from your expresses all part of the same network. Your devices will automatically switch to the strongest signal, and you won't kill all your bandwidth.

 

[Bengt77]

Thank you for your reply. You made a misassumption with the 10Mbps, though. I checked the speed using Speedtest.net, an online service. My connection really is a very steady 10Mbps was slowed down to only 1,5Mbps with all the AirPort Expresses plugged in. The speed is good again now, but only because I'm only using the main base station at the moment. Indeed, just like you guessed, as a wireless router. I don't want to hard wire them, as I don't want to run an ethernet cable through my house, through several rooms, for over fifteen meters. I'd rather not use one of the Expresses than hard wiring it.

I'll try using two Expresses and see if that still slows down my connection speed. AirTunes shouldn't, you say? Good to know, as I really like that feature. With my internet connection being 10Mbps and AirTunes using (and I'm just guessing here) another 10Mbps, that's 20Mbps. A wireless network operating at g-speed (my Wii doesn't have n, and I think I've read that a wireless network is only as fast as the slowest link) is 54Mbps. Divided by two, that's still 27Mbps, which should be more than enough bandwidth without slowing down the internet connection. Am I right in my assumptions?

Anyway, I still think it's extremely weird and annoying.

 

[waw74]

Sorry, I got MBps and Mbps confused. the big/little B makes a difference.

10Mbps is 1.25 MBps which is about what my connection is. the network speed is 10/100/1000 MBps
also keep in mind that using 100% of your upstream (like with torrents) can kill your downstream. so you want to throttle your torrents to about 75% of your available upstream.

On my system, airtunes eats up 125-150 KBps (or 1 - 1.17 Mbps) on average. so that just comes out of the available bandwidth.

and the 54/27 numbers are theoretical, perfect world. You would probably never see these in real life. I just did a quick file transfer check on my G network, and I get about 15 Mbps. thing like walls, and electrical interference can take a toll on your speed.

you could also run 2 networks, one B/G and one N, which is what i do. Just make My_Network_G and My_Network_N or whatever you wanted to do. but without a router that can cause problems, since they would be on 2 separate networks.

if you want speakers in a room without a slowdown, if you have the express just join the network, it won't drop the speed unless you are streaming music to it.

 

[Bengt77]

Okay. Now I have the AirPort Express in the living room set up to only join (and not extend) the wireless network created by the Express next to the ADSL modem, and there's no noticeable slowdown of the wireless network. Nice! Even with AirTunes being active, my internet speed is still 10Mbps. Finally, it's working as it should!

(Although there's still no good wireless signal in the back of the house, but I guess I'll just have to live with that.)

Thanks for your help, waw74. Greatly appreciated.

 

[waw74]

glad to be of help,

If there's anyway to get a cable to the back part of the house (through the attic, under the floor, and out a window can work), you could set up the second base like i said above, and get the connection in the back.
If you are (or have a friend who is) handy, you could even do a wall mounted plate.

you can buy a spool of cat5, and the connectors at home depot (probably better prices elsewhere) and make your own cable, the crimp tool to make the connection can be a little pricey for making one cable, but ask one of your geeky friends if they have some you can borrow. (I personally have 2, since i lost then found a pair)

you could even try something like this ethernet over power line adapter to get the wired connection to the back of your house. I've never used one, and the speed is kinda slow, but for surfing the web should be fine.
there are other brands out there too, do some comparative shopping and reading of reviews before you buy.

 

[brentsg]

EDIT: Switching off the two extra base stations, turning off WDS on the main one and restarting both the main AirPort Express and the ADSL modem is something I only just thought of, and guess what? It did the trick. My true internet speed is back: 10Mbps. But one huge question mark remains: why does the speed go down so drastically when using multiple AirPort Expresses? And AirTunes? Does anybody here have a clue, because I would really like to have an answer to that question.

It's how WDS works. Go read all of the free documentation that Apple makes available. When you have multiple nodes relaying information to each other you significantly reduce throughput, exchanging it for range.

 

[Bengt77]

you could even try something like this ethernet over power line adapter to get the wired connection to the back of your house. I've never used one, and the speed is kinda slow, but for surfing the web should be fine.
there are other brands out there too, do some comparative shopping and reading of reviews before you buy.

Hmmmm... that might be something to look into. Thank you for the link. Indeed, 14Mbps isn't very fast, but should be enough for full throughput of my 10Mbps internet connection. Could I, as my ADSL modem has two ethernet ports, connect one of those things to my modem, and the other in the back room, connected to an AirPort Express? Well, of course I could, but the question is really if I could set up that AirPort Express to create another wireless network with the same name as the one created by the one next to my modem? Would that work, or would the two networks interfere like crazy? Would, in that case, setting them both up to distribute their signals at different channels work that out?

Oh, all these questions...

It's how WDS works. Go read all of the free documentation that Apple makes available. When you have multiple nodes relaying information to each other you significantly reduce throughput, exchanging it for range.

Yeah, I learned that the hard way. A real bummer.

 

[waw74]

yes you can have 2 bases broadcasting the same network name, you just want the different channels. details are in my first post in this thread.

the problem is, that unless your modem has a firewall built in, which might be possible since it has 2 network ports, the way you would have to set it up for the expresses to see each other would not be very secure. normally the expresses wall off access to the wireless from the wired side.

one quick way to see if you have a firewall built in is to check the ip address that your express has, just check on the main screen of airport utility. If it starts with 192.168 or 10.0, then you do have a firewall in place. and you can add extra wireless bases fairly easily.

 

[Bengt77]

Yeah, I know for sure that there's a (pretty good) firewall running in the modem. Sometimes I do a port-check just for fun, and it always comes through perfectly. And yes, I have my modem set up so, that it distributes IP-addresses via DHCP to all attached network clients, be it wired or wireless. So of course, my MacBook, Wii and both AirPort Expresses all have 192.168.1.XX IP-addresses. Does that mean I'm all set, then?

 

[waw74]

yeah, on the expresses that are acting as wireless base stations, just make sure on the internet settings page "connection sharing" to "off (bridge mode)"

that will let your modem/router act as the master DHCP server for all things on your network. and enable the 2 wireless networks to see each other.

 

[Bengt77]

Alright. All is clear, then. Thanks for all your help, guys.

 

[Bilckie]

This is a great thread, well explaining the issue.
I was just about to go out and buy me a second Express to cover my whole place, but after reading this I need to reconsider my strategy

I was thinking about the following.
Since I don't want to pull cables through my house as well, I would basically try to use one of these Ethernet over powerline tools.

I have an Airport Extreme linked up to my modem and I would put one line coming out of the Exreme into the power plug. Then, at the other side of the house, I would connect the Express to the other side of the power plug.
Anyone any experience with this kind of setup? Or with these ethernet over powerline tools? What would performance be like?

Thanks in advance