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Go To Sleep, Go To Sleep, Go To Sleep Little iPhone

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In some circles, Apple Wi-Fi devices are knows to have problems with lost connections.  iPhones and iPads will unexpectedly miss incoming calls, have delays in receiving push notifications and even be forced to reauthenticate.

There is a solution to Apple devices' connection problems, and as with most "device problems", the fix resides on the infrastructure.  The DTIM setting needs to be increased.  (Apple recommends a setting of 3 or higher.)  Here's why:

Some Apple Wi-Fi connection problems stem from Apple iOS devices' use of 802.11 power management.  To understand what Apple devices are doing with power management, one must first understand how 802.11 power management works.

Let's start with unicast data.  The 802.11 standard allows devices' Wi-Fi radios to enter the Doze state in order to conserve battery life.  Wi-Fi radios in the Doze state are unable to receive data from the AP, so APs buffer all unicast data that has a destination MAC address of a…
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Why You Should Stop Disabling Low Wi-Fi Rates, Illustrated

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The last Sniff Wi-Fi post; on why Wi-Fi professionals should stop disabling low data rates, was met some resistance.  Be it in the comments or on Twitter, several experienced Wi-Fi folks disagreed.

All arguments in favor of disabling low rates (the ones that were presented to me, at least) were refuted in the text of the Leave, Leave, Leave My Rates Alone blog post.  But text is a less accessible messaging method.  "A picture is worth a thousand words", as the old saying goes.

If pictures will get the message across better, then pictures are what I'll use.  What follows is an illustrated look at why disabling low data rates is a bad idea.

 It's gauche to begin an illustrated work with text, but to understand the problem with disabling low Wi-Fi data rates one must first accept some facts about Wi-Fi devices (smartphones, laptops, etc.):

1. Wi-Fi devices -- not APs -- control associations and roaming.

2. Wi-Fi devices roam based on low received signal strength (RSSI) -- …
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WPA3 Adds Four Security Enhancements, One of Which Matters

The Wi-Fi Alliance announced its next security enhancement today, called WPA3.  The press release touts "four new capabilities", but only one of the four affects practical Wi-Fi security.

 As they are occasionally wont to do, the Wi-Fi Alliance announced a new certification today via a press release featuring an artisnal blend of normal words and corporate gobbledygook.  For those who speak fluent corporate gobbledygook, here are the four enhancements of WPA3:
Robust protections even when users choose passwords that fall short of typical complexity recommendations.Simplify the process of configuring security for devices that have limited or no display interface.Strengthen user privacy in open networks through individualized data encryption.A 192-bit security suite, aligned with the Commercial National Security Algorithm (CNSA) Suite from the Committee on National Security Systems to forther protect Wi-Fi networks with higher security requirements such as government, defense, a…
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