High latency on Apple devices vs. Windows

[btt]

New to Ruckus and working on a deployment for a hotel/resort property. We've gotten reports of connectivity issues with the POS system that runs on iPads carried around by the servers. I did some digging and I noticed high latency spikes when pinging the iPads. Pings will sit below 10ms for maybe 10 pings, then bounce up anywhere between 50-250ms for another 10 pings or so, then come back down, with some variations. I'm able to reproduce this issue with Apple laptops as well. We've done a site survey, signal and SNR values all look good. What's odd is on Windows devices I'm not able to reproduce the issue. A windows devices connected to the same WLAN on the same AP as a Mac device will maintain low latency, while a Mac or iPad will spike. 

I have a case open with support, but I wanted to see if anyone had any suggestions/tips on things that can be done from a config standpoint to try and make Apple devices happier. I'm running the latest version of the vSZ and using R720s and T710 omnis. Thanks. 

[itdept_head_me]

ruckus are top hole on sorting things out....

It's the only reason i use their kit...... sometimes it takes them a bit longer but they get there eventually....

[jkrainak]

Long story short, +1 on this problem.  We have been experiencing random latency with Apple MacBooks.  Pings go all over the place from the device to the Internet or gateway.  Pings to the AP are solid. 

[btt]

So I've had an update from the engineering team, via the support engineer I'm working with.

It seems that they believe the issue is how Apple handles powersave mode on their device wireless NICs. Engineering is claiming that high latency coincides with when the wireless NIC on the Apple device enters powersave mode and the AP has to buffer packets. I've asked them to troubleshoot further and get Apple involved to see what can be done. 

I've included the short report engineering sent me attached to this post as images. It provides some explanation of what they believe they've found, along with some packet capture data. 

We'll see where this goes next....

[itdept_head_me]

Apple are unlikely to assist in this , since it will seriously affect their "power save" and battery lifetime figures.

 it's all about looking good in the sales literature,  not performance under real world conditions.

Sadly it is not the only thing that is going on at Apple.

[btt]

That is my fear, but I'm going to keep pushing.