13 Replies Latest reply: Dec 22, 2013 8:44 PM by gordon9291
gordon142 Level 1 Level 1 (15 points)

When my new mid-2013 MacBook Air (i7/8 GB/512) connnects to my Cisco E4200 router, it gets terrible latency. If I ping the router, I get massively differing latencies from successive pings, between 1 and about 200 ms. Rebooting the router fixes the issue briefly, but it comes back after a few minutes.

 

This issue only occurs between this exact router and this MacBook Air. Any other systems have latency consistently under 1 ms when connected to this same router (two 2011 MacBook Airs, 1 2010 MacBook Pro, a Dell, and a Toshiba system). My 2013 MacBook Air also has normal latency (< 2 ms) when connecting to an older router I have around. The Air also works fine if I wire it directly into the router, however, the issue does not seem to be interference. It happens on both the 5GHz and 2.4GHz bands, regardless of channel used, and regardless of distance from the router - the symptoms are identically in all cases.

 

The issue also does not occur if I boot the Air into Windows 8 - pings are always under 1 ms, so it looks like we're talking a software issue. I've tried creating a new user profile and dumping all network preferences that I'm aware of, but it made no difference. I'm wondering if it's a very particular driver issues on the Mac side, although I find it very weird that rebooting the router temporarily fixes the issue (toggling wifi on and off has no effect). I've tried updating to the latest version of the router firmware, but it made no difference.


MacBook Air, OS X Mountain Lion (10.8.4), Mid-2013 13" i7 / 8 GB / 512 GB
  • Zane W Level 3 Level 3 (670 points)

    Have you installed this update?

     

    http://support.apple.com/kb/DL1672

  • gordon142 Level 1 Level 1 (15 points)

    This update did not help. With some more testing, I did notice something interesting. The high latency occurs only when the network is mostly idle. If I initiate a large, fast download, the ping consistently hovers around 1ms until the download finishes, at which point it shoots up again. I wonder if something on either the router or the Air's network card is going into a power-saving mode when their is little network traffic and can't wake up fast enough to respond appropriately to the ping request. This does not fully explain why I don't get high ping with my other router under the same conditions (and why no other Macs have the issue with this router)

  • airric Level 1 Level 1 (0 points)

    I just got the 2013 macbook air i7/8/256 and had this same annoying latency problem, I changed the wifi channel from 1 to 6 and now it's very fast, no hangups at all. Hopefully they fix this though in a future update so it doesn't matter what channel is being used.

  • gordon142 Level 1 Level 1 (15 points)

    Channel makes no difference for me (and I pretty much have to set it to the one furthest from what the neighbors use [5, in my case]). Are you sure you aren't getting a better signal on channel 6 simply because there is less interference on that channel? (I find Wifi Explorer's graph mode very helpful for calibrating networks to avoid interference. https://itunes.apple.com/us/app/wifi-explorer/id494803304?mt=12)

  • JeFFJuH Level 1 Level 1 (0 points)

    I'm experiencing the same with my Mid-2013 MacBook Air 13".

    Running OS X 10.8.4, with all recent updates.

     

    No matter what accesspoint I connect to, this behavior occurs on all of them, on both 2.4 and 5 GHz. (below is tested with a Netgear WNDR3700 v2 running OpenWRT on 5 GHz)

     

    PING 192.168.1.1 (192.168.1.1): 56 data bytes

    64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=9.154 ms

    64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=1.263 ms

    64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=55.010 ms

    64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=77.677 ms

    64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=1.329 ms

    64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=123.504 ms

    64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=147.128 ms

    64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=170.009 ms

    64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=192.810 ms

    64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=10.749 ms

    64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=33.638 ms

    64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=56.455 ms

    64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=79.391 ms

    64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=102.050 ms

    64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=124.849 ms

    64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=147.661 ms

    64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=1.248 ms

    64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=193.392 ms

    64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=2.085 ms

    64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=34.207 ms

    64 bytes from 192.168.1.1: icmp_seq=20 ttl=64 time=57.022 ms

    64 bytes from 192.168.1.1: icmp_seq=21 ttl=64 time=79.853 ms

    64 bytes from 192.168.1.1: icmp_seq=22 ttl=64 time=103.737 ms

    64 bytes from 192.168.1.1: icmp_seq=23 ttl=64 time=126.523 ms

    64 bytes from 192.168.1.1: icmp_seq=24 ttl=64 time=149.327 ms

     

    Altough it doesn't seem to affect my surfing and downloading experience. I still get around 60 Mbit down/6 Mbit up as advertised by my ISP, and I don't experience any actual delays at all.

  • richard_vd Level 1 Level 1 (0 points)

    Thanks for the hints.

     

    I posted a possible workaround here: https://discussions.apple.com/message/22760265#22760265

    It involves keeping the Airport card awake by pinging the router 5 times a second.

  • alpracka Level 1 Level 1 (0 points)

    Hello,

     

    I have noticed the same problem. I have 802.11g router 5 meters from my Macbook Air 2013 i7, 8GB, 256GB without any barriers and the connection just *****.

     

    The ping command output:

     

    nikos-mac:~ nikos$ ping 192.168.1.2

    PING 192.168.1.2 (192.168.1.2): 56 data bytes

    64 bytes from 192.168.1.2: icmp_seq=0 ttl=64 time=144.793 ms

    64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=58.123 ms

    64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=1.628 ms

    64 bytes from 192.168.1.2: icmp_seq=3 ttl=64 time=98.958 ms

    64 bytes from 192.168.1.2: icmp_seq=4 ttl=64 time=19.541 ms

    Request timeout for icmp_seq 5

    Request timeout for icmp_seq 6

    Request timeout for icmp_seq 7

    64 bytes from 192.168.1.2: icmp_seq=8 ttl=64 time=12.303 ms

    64 bytes from 192.168.1.2: icmp_seq=9 ttl=64 time=36.112 ms

    64 bytes from 192.168.1.2: icmp_seq=10 ttl=64 time=54.027 ms

    64 bytes from 192.168.1.2: icmp_seq=11 ttl=64 time=1.681 ms

    64 bytes from 192.168.1.2: icmp_seq=12 ttl=64 time=104.306 ms

    ^C

    --- 192.168.1.2 ping statistics ---

    13 packets transmitted, 10 packets received, 23.1% packet loss

    round-trip min/avg/max/stddev = 1.628/53.147/144.793/46.402 ms

     

    Interesting fact is, that if I go to the Windows 8 via Boot Camp, the ping on the router is nice around 1 ~ 2 ms (as other devices in my house). So i guess this is some kind of software problem and I'm sure Macbook wasn't downloading anything when I was testing.

     

    Well, not happy with that. This is serious problem.

  • mtsgrd Level 1 Level 1 (0 points)

    I experience this same issue with a mid-2013 macbook air. It seems this issue is definitely related to a form of power saving.

     

    Pinging my router once a second:

     

    $> sudo ping -i 1 -c 10 192.168.1.1

    PING 192.168.1.1 (192.168.1.1): 56 data bytes

    64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=28.578 ms

    64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=58.095 ms

    64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=81.163 ms

    64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=105.476 ms

    64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=21.862 ms

    64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=38.302 ms

    64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=61.123 ms

    64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=85.495 ms

    64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=7.756 ms

    64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=19.006 ms

     

     

    --- 192.168.1.1 ping statistics ---

    10 packets transmitted, 10 packets received, 0.0% packet loss

    round-trip min/avg/max/stddev = 7.756/50.686/105.476/31.026 ms

     

    Pinging it ten times a second:

     

    $> sudo ping -i 0.1 -c 10 192.168.1.1

    PING 192.168.1.1 (192.168.1.1): 56 data bytes

    64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=70.497 ms

    64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=2.959 ms

    64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=2.397 ms

    64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=3.364 ms

    64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=1.478 ms

    64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=1.800 ms

    64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=2.210 ms

    64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=1.766 ms

    64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=1.752 ms

    64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=1.189 ms

     

    --- 192.168.1.1 ping statistics ---

    10 packets transmitted, 10 packets received, 0.0% packet loss

    round-trip min/avg/max/stddev = 1.189/8.941/70.497/20.528 ms


  • bwredman Level 1 Level 1 (0 points)

    I'm seeing the same thing on my Macbook Air Mid-2013:

     

    ➜  sample_logs git:(master) ✗ ping -c 100 -i 0.1 -q 192.168.1.1

    PING 192.168.1.1 (192.168.1.1): 56 data bytes

     

     

    --- 192.168.1.1 ping statistics ---

    100 packets transmitted, 100 packets received, 0.0% packet loss

    round-trip min/avg/max/stddev = 0.834/1.740/12.895/1.801 ms

    ➜  sample_logs git:(master) ✗

     

    Here's with 1 second between pings:

     

    ➜  sample_logs git:(master) ✗ ping -c 100 -q 192.168.1.1

    PING 192.168.1.1 (192.168.1.1): 56 data bytes

     

     

    --- 192.168.1.1 ping statistics ---

    100 packets transmitted, 100 packets received, 0.0% packet loss

    round-trip min/avg/max/stddev = 0.777/74.987/200.133/63.815 ms

    ➜  sample_logs git:(master) ✗ ping -c 100 -q 192.168.1.1

     

     

    Pretty disappointing that nothing has been done about this for so long.

  • Jeff Geerling Level 6 Level 6 (11,100 points)

    Same exact problem happening here, and it's making some of the applications (like Network Connect/VPN) misbehave, for some reason.

     

    Without ping running every 0.2 seconds, I get about 20-40% deviation in ping times. With it running, I get ping times within 2-6%, and latency everywhere is vastly improved.

     

    My wired network connection is perfectly fine (USB Ethernet); it's just the WiFi.

     

    I have saved an alias in my .bash_profile so I can just type in the command 'fixwifi' after opening in the terminal, which runs the following (allowing me to quit Terminal after kicking off the job—to quit it, you need to find the process ID and kill it):

     

    nohup ping -i 0.2 10.0.1.1 > /dev/null 2>&1&

     

    I've been to the Apple Store for two genius appointments. The first time, they replaced my AirPort card. Second time they 'captured' the Air and did a 'stress test' on it, and found no issues. I'm guessing they're popping onto speedtest.net, and downloading some large files, and seeing that throughput is fine.

     

    Yes, throughput is fine, for large files. Latency is not—and that's the major issue here. Something seems to be 'power napping' the WiFi chip or something, causing random latency issues.

     

    I've tried toggling Bluetooth and Power Nap to no effect. The only thing that works is to DOS my router by pinging it 5 times/second.

  • Jeff Geerling Level 6 Level 6 (11,100 points)

    Additional info: I've also done the same exact tests on my wife's 2011 Air and my Dell Windows 7 laptop, right next to my laptop, and those laptops have had no issue at all. I've tried on the following routers:

     

    • AirPort Express with 802.11n/g/b mixed mode
    • Netgear 802.11n router
    • Corporate WiFi / WPA2 Enterprise 802.11g

    Same exact problem on all these networks. I wish I could test on a new 802.11ac AirPort Extreme, but I don't have one laying around .

  • Jeff Geerling Level 6 Level 6 (11,100 points)

    More troubleshooing info:

     

    On my home network, where I have controll over the access points, I switched my AirPort Express from 802.11n (b/g compatible) to 802.11n (a compatible), and now everything works like normal (full speed, low latency, no hack required).

     

    Unfortunately, I can't change any settings on my employer's WiFi or anywhere else for that matter. But if you only use your MBA in one location and have control over the router, and can switch it to an 802.11n mode, it might help.

     

    I'll be scheduling another genius appointment soon .

  • gordon9291 Level 1 Level 1 (0 points)

    In my case, it happened on both 5GHz and 2.4GHz bands, and the 5GHz band has never supported anything but a/n/ac.

    Jeff Geerling wrote:

     

    More troubleshooing info:

     

    On my home network, where I have controll over the access points, I switched my AirPort Express from 802.11n (b/g compatible) to 802.11n (a compatible), and now everything works like normal (full speed, low latency, no hack required).

     

    Unfortunately, I can't change any settings on my employer's WiFi or anywhere else for that matter. But if you only use your MBA in one location and have control over the router, and can switch it to an 802.11n mode, it might help.

     

    I'll be scheduling another genius appointment soon .