Where is my bottle neck?

Discussion in 'Mac Accessories' started by rpg51, Nov 18, 2012.

  1. rpg51 macrumors 6502

    rpg51

    Joined:
    Jul 4, 2012
    #1
    I have having occasional (not severe) breaks in the music stream from Vermont Public Radio. The web site permits streaming at two bandwidths, one called high speed and one dial up. I have quite fast internet access from Comcast via supplied cable modem. From the modem I go to a Time Capsule. I have an Air Express (2011) that connects to the TC wirelessly. The AE connects to my stereo receiver with a wired connection to a phono plug. I use a MacBook Air with 4 gigs ram and Firefox to connect to the public radio web site and stream the music.

    I have occasional 1-2 second silent periods.

    Any suggestions? I could fairly easily connect the AE to the TC with ethernet cable if that would improve things.
     
  2. MCAsan macrumors 601

    MCAsan

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    Jul 9, 2012
    Location:
    Atlanta
    #2
    How do you know the breaks are not up upstream? I would suggest there is a real possibility that the breaks are caused by traffic priory vs load on the X number of routers between the Vermont servers and Comcast, inside Comcast, and between Comcast and your modem/router. If that is the case, not much you can do with it.
     
  3. Gav2k macrumors G3

    Gav2k

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  4. velocityg4 macrumors 68040

    velocityg4

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    Georgia
    #4
    Run a test at speedtest.net and post your results including latency.
     
  5. rpg51 thread starter macrumors 6502

    rpg51

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    #5
    20.71 Mb/s Download
    2.78 Mb/s Upload
    35 ms latency
     
  6. MCAsan macrumors 601

    MCAsan

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    Location:
    Atlanta
    #6
    broadcast from your iTunes library to see if there are any breaks. If yes, the wifi coverage and/of signal strength needs to be addressed. If no, the problem (s) are between your modem and the Vermont servers on the otherside of the internet. Not sure how you can address that without something like a larger guaranteed pipe from your cable company...and that is still not guarantee of no breaks from the source servers.
     
  7. rpg51 thread starter macrumors 6502

    rpg51

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    Jul 4, 2012
    #7
    Thank you that is very helpful. I will give it a try later today. Am I correct that a test with my Air Express connected to my Time Capsule via ethernet and with my computer connected to my Time Capsule via ethernet that would also serve to tease out a problem with my internal wifi performance?? Is it possible to connect the Air Express to the Time Capsule via ethernet cable?
     
  8. Benbikeman macrumors 6502a

    Benbikeman

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    London, England
    #8
    Your speeds look ok, but that's a pretty high latency time.
     
  9. rpg51, Nov 22, 2012
    Last edited: Nov 22, 2012

    rpg51 thread starter macrumors 6502

    rpg51

    Joined:
    Jul 4, 2012
    #9
    What is latency anyway? I do notice that these numbers vary depending on when I do the test and which server I select.

    Does my in house connection to the internet affect these results? I am using what seems to be a good strong wireless connection through a Time Capsule.


    Here two tests using two different servers this AM. The latency is up a bit - around 40.
     

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  10. Benbikeman macrumors 6502a

    Benbikeman

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    Location:
    London, England
    #10
    Basically a measure of how long it takes from a signal to reach the other end. It's measured by a 'ping' - basically sending a tiny packet of data and testing how long it takes before the other end reports it as having arrived.

    It matters more for some services than other, but it's important for streaming services. A lower number is better, and at 35-40 yours is a bit high.

    Here's mine as a comparison:

    [​IMG]
     
  11. rpg51 thread starter macrumors 6502

    rpg51

    Joined:
    Jul 4, 2012
    #11
    I will do some testing here and see if I get this problem running itunes alone - that will tell me a lot.

    It is interesting though because there have been times when I did have numbers like yours. It varies a lot.
     
  12. rpg51 thread starter macrumors 6502

    rpg51

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    Jul 4, 2012
    #12
    I spent some time playing iTunes using airplay from my laptop to the Air Express via wireless and I am having the same problem. So it appears that the problem is related to the hardware and software in my house - not my internet connection. Do any of you have a suggestion about how to go about making the diagnosis?

    This is my set up --- stereo receiver connected to air express via wire - air express connected to time capsule via wireless. Time capsule/air express connected to iphones and laptops via wireless. iMac attached to time capsule via ethernet.
     
  13. velocityg4 macrumors 68040

    velocityg4

    Joined:
    Dec 19, 2004
    Location:
    Georgia
    #13
    Since you mentioned possibly connecting the AE via Ethernet I would do so. You'll need to change some settings so it uses Ethernet rather than repeating the wireless. This help with latency on devices connecting via the AE.

    On any hard wired devices I would also set the DNS servers manually. For Comcast use 75.75.75.75 and 75.75.76.76 as the secondary.
     
  14. rpg51, Nov 22, 2012
    Last edited: Nov 22, 2012

    rpg51 thread starter macrumors 6502

    rpg51

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    Jul 4, 2012
    #14
    Ok. Not sure I am skilled enough to start making manual changes in the settings - but I will give it a try. This will take some time - I need to pull some wire from the time capsule in one room to the air express in the next room. Maybe this weekend.

    On the other hand - should I not be able to expect that with standard wireless set up the system will be robust enough to stream music? Even if it is wired to the TC I want to be able to stream wirelessly from my laptop and iphone.
     
  15. rpg51 thread starter macrumors 6502

    rpg51

    Joined:
    Jul 4, 2012
    #15
    Update

    I made a change in the Air Express settings and so far today it appears the issue may be resolved. I changed the "network mode" from "extend" to "join" a wireless network. So far so good.

    I assume the difference is that the AE will not send or receive direct from my laptops and iphones and that they will send the music via the time capsule??

    Whatever, I'm keeping my fingers crossed and hoping its this easy.
     
  16. smoge macrumors regular

    smoge

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    Jun 14, 2011
  17. rpg51, Nov 25, 2012
    Last edited: Nov 26, 2012

    rpg51 thread starter macrumors 6502

    rpg51

    Joined:
    Jul 4, 2012
    #17
    Don't think it is the isp. Problem occurs even when playing music from itunes - ie. not streaming.

    The problems are recurrent - not as bad - but still issues.

    EDIT: Not so fast - yesterday and today the evening speed results are awful - check this out:

    http://speedtest.net/result/2331882461.png

    UPDATE - I discovered this AM that the slow speeds are evident when my machine is inadvertently connected to an older wireless access point down in the basement which I am now going to disconnect. Could well have been the source of my troubles. Using my TC as the wireless the speeds are up to snuff.
     

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