Questions about extending a network with an Airport Express

Discussion in 'Mac Accessories' started by JW008, Dec 30, 2008.

  1. JW008 macrumors 6502

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    Apr 29, 2005
    #1
    I recently moved and before hand my set up was working perfectly for me: a Time Capsule on an "N-only" network and an old Airport Express in bridge mode for a "G-only" network. My iMac, MacBook, and AppleTV connected really well with the N network and my iPhone and Wii connected seamlessly with the G network.

    Since I've moved, I've seen the speed and range of both networks decreased significantly. For the G network this isn't much of a problem, the Wii is right next to the router and the iPhone can connect via the cell network. For the N network, I'm having more trouble. While my iMac can still connect to the N network, I rarely get speeds over 1 MB--even when I'm downloading something, Time Machine is backing up wirelessly, and attempting to stream something to the AppleTV. Instead, all three pretty much slow to a halt. My unibody MacBook cannot even connect to the N network, even when it's sitting right next to my iMac.

    While the distance of the Time Capsule/old Airport Express is not much different from my old place to the new, there are many more walls in the way in the new place, which I'm thinking is what's causing the slow-down and decrease in range.

    I'm thinking about buying another Airport Express to extend the N network, but I've got a couple of questions:

    1) I know this will extend the range of the network, but could it also increase the output to those devices that are currently not downloading/uploading/streaming as quickly?

    2) What would be the best way for me to test out the best placement of the new AE? I don't mind doing a little trial and error, but I was wondering the best method for this test. I understand that I need to just try the new AE in different outlets around the house, but what should I be doing to test the speed/range of the network?

    Thanks for everyone's help! I appreciate the guidance.
     
  2. brentsg macrumors 68040

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    Oct 15, 2008
    #2
    I believe that hopping off a remote base station configured as a repeater actually slows throughput, while extending range.
     
  3. JW008 thread starter macrumors 6502

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    Apr 29, 2005
    #3
    Really? While the range is a problem, the biggest problem is the slow throughput. If I do this, it will actually slow my network down?

    Another thing I need to add to the original post: I'm getting a full signal on my iMac, but like I said the highest I've ever seen the throughput is 1MB/sec. Could this be a problem with my iMac rather than my network (even though I never had this problem at my old place)?
     
  4. Cliff3 macrumors 65816

    Cliff3

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    SF Bay Area
    #4
    I would try simplifying things to see what the baseline performance is, then add complexity back in to see what change affects things. Try going back to the one n router and see what Network Utility reports as the link speed.

    FWIW, I have 2 802.11n WAPs in my network, both Airport Extremes configured to support b and g in addition to n, and Network Utility tells me my link speed is 130Mb/s. Adding a 3rd device to that, an Airport Express n router, doesn't affect that figure.
     
  5. JW008 thread starter macrumors 6502

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    #5
    What would be the best method for measuring baseline performance? Streaming something to the Apple TV? Backing up to the Time Capsule? Watching TV through Sling Player? Something different or all three? Or will network utility just give me a report based on the theoretical?

    I'll try this over my lunch break! Thanks for your help!
     
  6. Cliff3 macrumors 65816

    Cliff3

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    #6
    By simplifying, I mean go back to the one WAP and measure performance. Then add the second WAP back in and measure again. That will let you know if your WDS is the problem or not.

    What does network utility report as the link speed for your current configuration? In terms of real world tests, find a big file to copy from one workstation to the other. Measure how long it takes. Then make your change, and repeat the test.
     
  7. JW008 thread starter macrumors 6502

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    #7
    I'm back home and testing all this out. I unplugged the Airport Express that was running the G only network and left the Time Capsule running the N only network plugged in. Thus, everything below is running on the N only network.

    According to Network Utility the link speed is 270 Mbit/sec.

    With nothing else running, I'm copying a file that's 2.91 GB from my iMac to my Time Capsule to check out the real world capability. According to Activity Monitor my network speeds keep jumping around from 150 KB/sec to about 250 KB/sec. It looks like the transfer is going to take about an hour and since I've got to be back at work, I won't be able to see the final time. But as a benchmark: It took 2 minutes and 27 seconds to transfer the first 100 MB.

    I really do appreciate yours (and anyone else's) help on this. Is this normal for an N only network? Will getting that extra Airport Express to extend the N only network help with the throughput?
     
  8. Cliff3 macrumors 65816

    Cliff3

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    #8
    That is slow as mud. I am seeing 5-6MB/sec throughput from my MBP to an airport disk, where the workstation and the WAP are in the same room. A 1GB files copied over in roughly 4 minutes. You might try copying to your other computer to make sure it's not time capsule that is the bottleneck.
     
  9. JW008 thread starter macrumors 6502

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    #9
    I'm back at work now so I'll try it when I get home, but having transferred files pretty recently, it was not much faster (if any faster at all).

    I've only had this problem since moving into the new place, thus I'm pretty sure everything is working properly, it's the distance that's causing the slow speeds.

    Would getting an extra Airport Express help with throughput?
     
  10. Cliff3 macrumors 65816

    Cliff3

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    #10
    Try your test again when you're in close physical proximity to the router. If 150-250Kbps is the best you can manage, then I would be inclined to reset everything to factory settings and start configuring your network all over (again, measuring the impact of each change you make to determine which one is killing performance).
     
  11. JW008 thread starter macrumors 6502

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    Apr 29, 2005
    #11
    Thanks Cliff for all your help. I'll run these tests tonight when I get home from work.

    Any thoughts about the Airport Express, though? If I can get 30-50 Mb/sec on my MacBook right next to the Time Capsule, could an Airport Express help with the throughput to my iMac?
     
  12. Cliff3 macrumors 65816

    Cliff3

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    #12
    It will help if you need to extend the range of your network. I have two airport extremes - one here in my office on the first floor, and another upstairs that extends coverage to the second floor and into my garage. A second WAP will help throughput if you need to have network access somewhere that is not getting a strong signal from your existing WAP.
     
  13. JW008 thread starter macrumors 6502

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    Apr 29, 2005
    #13
    Excellent. That's exactly what I was wondering. I'll check all this out when I get home this afternoon.

    I really appreciate all the help!
     
  14. JW008 thread starter macrumors 6502

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    #14
    Thought I'd update with the benchmarks:

    While the first ones are from my bedroom on my iMac (the 2 min 27 sec to transfer 100 MB-- a rate of about 5.44 Mb/sec), these are from my MacBook at various places around the house.

    The file I transferred was 645.4 MB and I tested each room twice.

    Living Room next to router:
    Test 1: 1 min 33 sec (55.52 Mb/sec)
    Test 2: 1 min 29 sec (57.69 Mb/sec)

    Upstairs Office:
    Test 1: 1 min 38 sec (52.41 Mb/sec)
    Test 2: 1 min 36 sec (53.67 Mb/sec)

    Bedroom (upstairs, next room over from Office):
    Unable to test because cannot connect with MacBook

    I'm heading to Best Buy to buy the Airport Express in a few hours. Hopefully if I plug in the upstairs office it will produce enough of a signal to transfer the 10 feet to my bedroom.
     
  15. Cliff3 macrumors 65816

    Cliff3

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    #15
    Sounds good. You may want to retire the older APExp and just run a network that supports b and g clients in addition to n. That's what I'm doing and performance is perfectly acceptable.
     
  16. johnnj macrumors 6502a

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    #16
    WDS cuts the potential througput by 2/3 because each packet is transmitted three times and each device only has one transceiver, doing double duty (client-AP/AP-AP).

    If you want to extend your WLAN topology without running cabling, you might want to consider connecting two AP's via a PowerLine ethernet system.

    You'd just run the far AP in bridged mode with the ethernet of the PowerLine device connected to one of the regular switch ports of the AP/router and all the routing/DHCP stuff turned off. You can set the far AP with the same SSID/security settings as your main router and the transition will be transparent to the client machines.

    I use this to extend my main wired/WLAN net, located on the 3rd floor of my house, down to the 1st floor. The PowerLine segement reports throughput of approximately 100 megabit. It's fast enough to stream divx/dvd iso from my HTPC (on 1st floor), but not fast enough to keep up with mkv/bd iso.

    Previous to this arrangement I tried using WDS and all it resulted in was problems and a complete lack of performance.

    John
     
  17. brentsg macrumors 68040

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    Oct 15, 2008
    #17
    The problem I have with powerline networks is they seem very sensitive and throughput is really dependent on how your home is wired and what devices you have powered on what circuits. I can get good throughput on some outlets and just terrible on others. I also find you need them plugged right into the wall, not on a surge protector, so I feel it opens a potential entry point for a surge.
     
  18. johnnj macrumors 6502a

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    #18
    Right.. that's what the two different systems I've used have all said in the manual. They also all said that the devices had some sort of surge protection built in.

    The Linksys one that I initially used was terrible. I was getting <10 megabit link. Currently I'm running the Netgear AV system which was a vast improvement (almost 10x) on the same wiring. I'm actually shocked that it does as well as it does, given that one end is on the 3rd floor of my house, with wiring on a subpanel that's hanging off of the main panel which feeds the room on the 1st floor with the other unit.

    Obviously PowerLine networking won't work for everyone, and the kits are kind of pricey (although if we're all Apple customers here, we're used to paying a lot, right?), but I think that if you can get it to work, it's far better than the inherently flawed WDS.

    Of course the best way to distribute a WLAN with wide coverage is to run ethernet, but that can have a negative impact on marital relations.

    :)

    John
     
  19. brentsg macrumors 68040

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    Oct 15, 2008
    #19
    That's what I was hoping for. Mine claims that I'm getting >80Mbit but in reality it can't stream my Netflix without dropouts, which my WDS G network can handle.

    I'm about to install a Slingbox HD unit so I know I'm about to choke my WDS... so I was bummed the Powerline wasn't the answer. I guess I'll go grab a couple Extreme N units to see how they do.
     
  20. Cliff3 macrumors 65816

    Cliff3

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    Location:
    SF Bay Area
    #20
    My Apple TV and Slingbox (non-HD - I've had it for a few years) are connected via gigabit ethernet now, as is the machine hosting my iTunes source library. It's all good so far...
     

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