BYOD policies aren't all they shape up to be, says Netscout

Bring your own device (BYOD) policies create a lack of device control, mobility issues, neighbouring network interference and guest authentication requirements.

That's according to Netscout, saying unconnected Wi-Fi devices are a big problem for organisations.

Some devices have a Wi-Fi radio that remains very active when the device isn't connected to a Wi-Fi network, even if the user is happily accessing cellular data.

Wi-Fi-enabled devices can also still degrade performance when not connected via Wi-Fi.

Amit Rao, director – APAC channels, NETSCOUT, says the problem, as so often is the case, is Wi-Fi bandwidth.

"Wi-Fi devices and access points (APs) share a channel. Only one device can transmit over the channel at any given moment, otherwise a collision is likely," he says. Channel sharing works fine for Wi-Fi, most of the time. When one device or AP begins transmitting, other devices and APs go quiet," he explains.

"Then, once data has been transmitted, all devices and APs go through a process called 'arbitration' to determine who sends next. The winner of arbitration sends data, thus starting the whole process over."

Rao adds that the main problem with Wi-Fi bandwidth is that it can fluctuate.

Wi-Fi devices use a protocol called dynamic rate switching (DRS), which lets devices switch between different data rates as needed.

"DRS is a good thing for Wi-Fi because different devices may need different data rates. When channel conditions worsen, low-rate Wi-Fi traffic can remain successful even as high rate traffic fails," he says.

"Whether distance, walls, mobility, interference or something else is causing unstable channel conditions, low data rates can allow a Wi-Fi connection to remain usable."

However, Rao explains that there is some good news in all of this.

"Wi-Fi devices have become less rude. Three or four years ago, Wi-Fi devices were extremely chatty when unconnected. While it is good that Wi-Fi devices are typically less chatty than they once were, unconnected Wi-Fi devices can still be a problem," he says.

"Certain Wi-Fi devices can get chatty enough to cause Wi-Fi performance and stability issues, especially in areas with dense concentrations of people. To address the problem, and provide more certainty, organisations should look at employing a Wi-Fi network analyser.