For example, you might find that a certain type of low cost laptop seems to always gravitate to 5 GHz connections, even in areas where 2.4 GHz coverage is much more reliable. Unfortunately, Discovery software can't solve the problem of devices connecting to unstable APs, but it can at least identify the problem. (I call it "Wi-Fi whack-a-mole" when you adjust one AP, solve a problem in one place, create a problem in another place and then keep repeating the process ad infinitum.) You can disable an AP radio (or even an entire AP, in extreme cases), but that may trigger a game of Wi-Fi whack-a-mole. So, if a smartphone decides that it wants to stay connected to an AP that's two rooms away or latch on to an AP that's on a congested channel or gravitate towards an AP that always seems to deliver inconsistent Wi-Fi, there's not much you can do about it. In Wi-Fi, devices - not APs - manage connections. All of those things are nice, but in the enterprise I find that I end up using Discovery software for two main purposes: to figure out whether my device is connecting to the best AP and to see if I need to adjust settings on deployed APs.ĭevices that don't connect to the best AP are frustrating because you often can't do anything about it. You can check your current RSSI, look to see which channels your neighbors' APs are on, try to find unencrypted SSIDs and, if you're using a more advanced Discovery tool like WiFi Explorer, even view Information Elements from Beacon frames to figure out what your APs are capable of. You just need to know what to do with it.ĭiscovery software can be used for a lot of things. It doesn't tell you about frames (commonly called "packets", but in the world of Wi-Fi the correct term is "frames") or other Wi-Fi devices or non-WiFi interferers (such as wireless speakers, microphones, headsets and the like). Basically, that means it gathers AP information. When using Discovery software, remember it's limitations: it only gathers 802.11 Discovery information. Once Discovery software is installed on a PRODUCTION DEVICE, then it's time to use Discovery software. My iPhone 5, being held in my hand right in front of my laptop, shows an RSSI of -55 dBm. For example, I'm sitting in my friend's office and my Apple MacBook laptop shows an RSSI of -62 dBm. On the other hand, if you're using Chrome OS then you're used to things that suck, so you should be fine.) It does you no good (and it can actually end up being COUNTER-PRODUCTIVE) to run Discovery software on a laptop if you're trying to support someone's iPhone. (I know that sucks for Chrome OS people because Chrome OS has no Discovery software. Windows: Acrylic WiFi (Tarlogic), inSSIDer (Metageek - $20)Īn important note to remember when using Discovery software is to always use Discovery software that runs ON A PRODUCTION DEVICE. Mac OS X: Wireless Diagnostics (Apple), WiFi Explorer (Adrian Granados - $15) If you want details about the options, read my previous post. (Pop Quiz: Why does the 802.11 standard have two different types of frames that carry essentially the same information?Ī: Probe Request/Response frames allow devices to connect to hidden/non-broadcasting SSIDs, while Beacon frames do not carry the SSID when the SSID is hidden/non-broadcasting.ī: Probe Request/Response frames allow devices to initiate 802.11 Discovery, thus potentially making roaming faster and giving devices a higher likelihood of connecting quickly in congested Wi-Fi areas.Ĭ: The designers of the 802.11 standard are stupid, and stupid people do things like creating two different frames that essentially do the same thing.ĭiscovery software is either free or cheap. Beacon frames and Probe Response frames carry essentially the same thing: information about the AP. Active Scanning involves a device sending Probe Request messages as a broadcast in the hopes of getting APs to respond with Probe Response messages. (Hence, the term "Scanner" software.) Passive Scanning involves a device listening for Beacon frames that have been sent by APs. There are two ways that 802.11 Discovery can be done: Active Scanning and Passive Scanning. Because the first part of my three-part series on Essential Wi-Fi Troubleshooting Tools is going to be about the free (or, very inexpensive) one: Discovery Software.ĭiscovery software, which is also called Scanner software, is software that records and displays information that a Wi-Fi radio gathers during 802.11 Discovery. You're reading a free blog, so I'm guessing the answer is, "all of us".
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