10 ms·
I build public Wi-Fi networks, you've probably used one of them. AMA if you have Wi-Fi questions. To say it "sucks" is a bit harsh. It's delivering multiple hu
by willidiots 10y ago
I build public Wi-Fi networks, you've probably used one of them. AMA if you have Wi-Fi questions.
To say it "sucks" is a bit harsh. It's delivering multiple hundreds of Mbps to you via an unlicensed contention-based medium. The air interface is like sending packets over a noisy Ethernet hub; it's impressive it works as well as it does. That said, this article's a good primer on some of the protocol's fundamental challenges.
In the coming years we'll hear more about 802.11ax, which is thankfully focused on efficiency vs. raw numbers, but likely won't be ratified until 2019/2020.
- bennofs 10y agoI've got a weird problem at my home where WiFi connection on my laptop gets really bad as soon as some particular other laptop connects to the WiFi. Reconnecting fixes the issue. Any idea what might cause this or how to gather more information on potential causes?
- kozak 10y agoTry to switch your router to 802.11n-only mode (no compatibility with b and g).
- esaym 10y agoI had the same issue with a $300 netgear prosafe AP. When certain 802.11ac clients would connect (mostly cell phones), it would randomly get periods of of complete grid lock in the wlan. All clients would have good signal strength but they had no data throughput. Disconnecting and reconnecting the offending client would restore the wlan throughput. The best I could see from packet sniffing was that these certain mobile clients would go into some kind of sleep mode, and when/if packets were transmitted to them, they would not respond with the proper ack (sometimes), the AP would then hang the whole wlan waiting for the ack (I guess). I tried several different netgear prosafe access points (all of them 802.11n). The only thing that worked was getting rid of my netgear hardware and replacing them with a Mikrotik wAP ac.
- koolba 10y agoWhich router do you recommend? Is the 5G band consistently worse than the default (i.e. constant connection drops) or is that just my experience?
- willidiots 10y agoAn unfortunate side effect of being in the industry is that I constantly have a surplus of enterprise-grade hardware at home. It's been a while since I looked at consumer hardware. Apple's Airports were solid, but have been discontinued. I've used both of the OnHubs and both were performant / stable. I've heard generally good things about Google's new Wi-Fi pucks, and Netgear's nighthawk series. 5G is the better of the two bands - it gives you many more channels and there's generally less interference. That sounds like something particular to your environment. If you have a Mac, I recommend installing Wi-Fi signal (https://itunes.apple.com/us/app/wifi-signal/id525912054?mt=12 https://itunes.apple.com/us/app/wifi-signal/id525912054?mt=1...) - it gives you much greater insight into what's happening on the air. I'd start by installing something like that, and monitoring for correlation with your drops - what else happens when your connection drops? Does the SNR drop? Does the AP change channels? etc.
- ericabiz 10y agoNot OP, but we run retail stores that do cell phone and computer repair, so we needed reliable routers that could routinely support at least 10-15 clients grabbing data at any given time. We've been using the Linksys WRT1900AC (now ACS) and they've been great. I have one here at home as well. I'm on a Gigabit connection provided by AT&T at home, and the router sits two rooms away with 2 walls between me and it. Also, my daughter is watching YouTube videos using it right now. With all that, I just ran a speed test using fast.com on my iPhone 6 and it showed 150Mbps. Really solid router.
- d33 10y ago> you've probably used one of them Could you give a few examples? ;)
- rwmj 10y agoHave you ever built "moving" wifi networks (trains, planes), and do those have special challenges?
- willidiots 10y agoYes and nothing special, as long as the clients and AP are moving consistent to each other. If the client is moving >10MPH relative to a fixed AP (i.e. you're driving past the AP in your car), Wi-Fi doesn't handle that well. Your movement creates Doppler shift in your RF signal, which Wi-Fi can't adjust for (vs. e.g. LTE which does).
- farabove 10y agoI worked a place that did roaming from one AP to another one on a train in Norway in the early 2000 / late 90s, think we was the first in the world to do it. To don't have a huge network drop we used a VPN connection on the client computer so it had the same IP while jumping from one wifi over to the other one.
- nojvek 10y agoCan you not sue modem providers for false advertising? America is a litigious country, I wonder why this hasnt happened? I filed a FCC complaint on Frontier delivering 10th of their speeds. They gave me an upgraded connection that gave me full 30Mbps within a week. The only way Corporations are going to learn how to back off is when they have to pay for their mistakes.
- lawry 10y agoWhat hardware, and what kind of settings do you need to seek to have a working roaming network? I've a Mikrotik router at home (very educational), and I've very often heard UniFi ap's can do it properly. Can I do it with Mikrotik aps? Will setting it up be hell?
- willidiots 10y agoIn general see my response to grk, you can roam with any network that meets these criteria: 1. All APs use the same SSID 2. All APs bridge users onto the same subnet But the experience will vary from client to client in terms of how aggressively they roam. Many AP vendors offer knobs to "help" clients roam by kicking clients off at a certain signal threshold, supposedly triggering a roam: in practice, this just upsets many clients. Re #1: "SSID" is actually shorthand for "ESSID" - Extended service set identifier. Each AP has its own "BSSID" - Basic service set identifier, which is the AP's Wi-Fi MAC address. The whole concept of an "ESSID" is to signal to clients that a certain group of APs belong to the same system. Re #2: If you need to scale beyond a single subnet, you generally solve for this by terminating users on a centralized packet core / wireless controller, which shards users out onto multiple subnets.
- aidenn0 10y agoI switched from single to multiple ESSID when I found most laptops would not switch BSSID until they completely lost connectivity. It was a shame because both Android phones one iPhone I tried worked great under this setup.
- grk 10y agoDoes roaming devices between APs actually work? I reading through ubiquiti forums and it looks like they used to support it, but backed out of it. My specific usecase is moving around the office while being on google hangouts on my phone.
- nerdbaggy 10y agoIt really depends on the phone and the AP. https://support.apple.com/en-us/HT202628 https://support.apple.com/en-us/HT202628
- lawry 10y agoI thought you could use aggressive approaches by letting the AP's just kick the device off the AP so it's forced to join a better one?
- nerdbaggy 10y agoIn theory that works, but a lot of phones get angry when the AP stops talking to it. It just assumes that you lost WiFi and disconnects and doesn't try to rejoin right away
- grk 10y agoThanks, that link is very informative.
- cmsimike 10y agoI believe it is the responsibility of the client to correctly roam between similarly named APs. I vaguely recall reading into this when I read that my unifi AP didn't support roaming. I could be mistaken though!
- willidiots 10y agoYes it absolutely does, but it is dependent on the station (the client) doing so. One of my gripes about Wi-Fi is that it delegates too much to the station - your experience is thus dictated by whoever wrote your phone/computer's Wi-Fi chipset driver, and how they interpret the standard. Any Wi-Fi network supports roaming on the network side, you just need all of your access points to use the same SSID, and to dump users onto the same subnet consistently (otherwise you'll need to re-IP after roaming).
- Pxtl 10y agoOnce you're connected wifi is great. It's the long connection negotiation and the slow reconnection process if it gets interrupted or you switch networks that's infuriating. I get upwards of a minute of downtime when I switch from my router to my AP at home.
- zaroth 10y agoVirtually none of the handoff delay is actually due to L1 or L2. The PHY handoff itself can happen in less than 10ms, and with Pre-Auth that handoff is actually happening before you even leave one AP for another.
- Pxtl 10y agoIt may simply be the DHCP that's the problem - the step it's hanging on is always "requesting IP address". I've tried fixed IPs and that hasn't helped. Part of the problem is that even though I bought a designated access point device instead of a generalist wifi router (and I suspect it's the same device with marginally different firmware), the configuration process to make this stuff work is completely opaque. I have no idea what I'm doing right or wrong, and every guide says something different - at this point I'm at just "give both networks the same SSID and encryption and password and hope it all works out".
- dfox 10y agoSetting all APs in one network to same ESSID is exactly wbat you should do and for half-reasonable APs that works well. Big name brand vendors will sell you APs that support some proprietary coordination mechanism between them (usually with central "wireless network controller" as separate device), but that is not required for roaming to work. Such solutions (apart from centralized management) are mostly to keep your APs from interfering with each other (which is non-issue unless you have more than three and unless they are placed in unfortunate physical locations).
- jlgaddis 10y ago
- hashkb 10y agoHow do you feel about the way WiFi is marketed to the public? I think that's the main thing OP is saying "sucks".
- mseebach 10y agoIs there a good suite of tools to actually measure the quality of a wifi connection and/or surface, even help diagnose, problems?
- Obi_Juan_Kenobi 10y agoWifi Analyzer is a good place to start. https://play.google.com/store/apps/details?id=com.farproc.wifi.analyzer&hl=en https://play.google.com/store/apps/details?id=com.farproc.wi...
- anth1y 10y agoIt really depends on your Operating System.
- FabHK 10y agoOn macOS, someone below recommended "WiFi Signal", USD 5. Not so fully featured, I assume, but free is Wireless Diagnostics. Ignore the popup, and go to Windows -> Info/Scan/Performance (it's in System -> Library -> CoreServices -> Applications, but I start it via Spotlight)
- ValentineC 10y ago> Not so fully featured, I assume, but free is Wireless Diagnostics. Ignore the popup, and go to Windows -> Info/Scan/Performance (it's in System -> Library -> CoreServices -> Applications, but I start it via Spotlight) Protip: it's also easily accessible by holding Option and clicking on the Wifi icon in the menu bar.
- tlow 10y agoFing for services and ping?
- majewsky 10y agoThat's at least one OSI layer north of what was being asked.
- digler999 10y agowhy does authentication take so damn long ? Why can't it happen in a blink of an eye ?
- LogicX 10y agoYou should put contact info in your profile.
- wazanator 10y agoWhat security measures do you use to prevent someone from knocking a connected user off and redirecting them so they reconnect to an evil twin AP?
- FeatureRush 10y agoHow does Wi-Fi compares to other alternatives for gaming? Which would you suggest to minimize lag introduced on the last mile?
- Groxx 10y agoAny idea why we do not have public, encrypted wifi? Seems like it should be easy / trivial to fix, and protects people from passive listeners.
- epmaybe 10y agoNot sure what you mean by this. Https exists, no?
- krallja 10y agoHTTP is not the only traffic on a network. DNS is rarely encrypted, and many email providers use STARTTLS, which starts unencrypted.
- yjftsjthsd-h 10y agoSadly, https is pervasive but not universal.
- nisa 10y agoNot OP, but there are some ideas like EAP-UNAUTH-TLS but it's not well (at all?) supported. Some details: https://lists.eff.org/pipermail/tech/2012-December/000333.html https://lists.eff.org/pipermail/tech/2012-December/000333.ht...
- geggam 10y agoand then someone turns on a leaky microwave oven and you get nothing
- Eiriksmal 10y agoWow, that article taught me that our office is probably using the wrong setup for optimal VoIP performance. When I started, I bought us an Asus RT-N66U to replace the ancient 802.11g router that was powering the 5 computers, 4 smartphones, 3 ethernet VoIP phones and 1 printer. Fast forward two years and now we have 12 computers on wifi using soft phones, 3 engineering rigs on ethernet, 11 smart phones, and that lonely printer. I'm now thinking that our occasional VoIP issues probably aren't Time Warner (er, "Spectrum," whatever)'s fault, but might be caused by overwhelming the physical capabilities of our router. So what sort of hardware should I plead with our CEO to let me purchase? Is there any way I can test, calculate, or prove that upgrading the infrastructure will prevent the operational staff from saying "Hello..? Hello..? Can you hear me?" on a phone call? It sounds like, from hopping over to the linked CNet article, that maybe putting another router with the same network name and password, hardwired into the opposite corner from the existing router, would let us split the load across the office. But the end of Anand's article says I should throw up my hands and quit because the back room where a new router would go can still hear the original Asus transmitting loud and clear, so client devices would still have delays caused by picking up other networks.
- krallja 10y agoYou can put the twin APs on different channels, and the two collision domains shouldn't overlap.
- Eiriksmal 10y agoSo he's specifically referring to collision on the same channel, not that a device connected to Router A on 2.4 channels 1->4, but can also see Router B on channels 10->13 has to wait to transmit data back to Router A.
- el_isma 10y agoYes, collision occurs on the same channel transmit. You'll probably have to setup two different essids. Most devices I've used will keep using the same ap even when its signal is lousy and they have a great signal to the other ap
- gonzo 10y ago> I build public Wi-Fi networks, you've probably used one of them. AMA if you have Wi-Fi questions. Interesting. I helped start Wayport (now AT&T WiFi Services) and subsequently worked at Vivato for a while. Which public WiFi networks are you responsible for?
- Spooky23 10y agoSeriously. Wifi is a miracle product. Even if you forget the ubiquity of it... it saves ridiculous amounts of money. 15 years ago, we'd spend like $50k to wire up new office space for 100-150 people. Now... maybe $5k with cable pull.
- bartvk 10y agoYeah, it's ubiquitous but I'm not so hot on the reliability. It may save a lot of money to not wire up an office, but I wonder what the production losses are due to less reliability.
- deleted 10y ago[deleted]
- hchenji 10y ago802.11ax won't mean anything unless you reduce interference (see my reply below). Without high SNR, all these new efficiency techniques won't get you anything. Shannon capacity is still what limits performance.
- dzhiurgis 10y agoAt my townhouse there are times that 2.4 GHz network dies completely in main floor. Usually its evenings, sometimes feels its periodic. Latency sky rockets even when I am 1 meter from the router. What are the practical ways to find interference? The tools I have is openwrt router and a macbook. I normally use 5GHz anyway, but wireless music device is still 2.4GHz which is incredibly annoying once it dies.
- ioquatix 10y agoWe had a specific lounge chair, which when you sat in it with a laptop, if someone was using the microwave, the wi-fi would drop out. If you stood up, everything was fine. We took that lounge suite to the holiday house. Good riddance :)
- jedberg 10y agoIt's almost certainly a microwave or cordless phone. I still forget sometimes and knock out my own wireless with a microwave.
- dzhiurgis 10y agoIt's definitely not mine. The effect is crazy tho. I wanna at least find a way to find the source/direction of it.
- lucb1e 10y agoapt-get install wavemon I love that tool. Tells me signal strength and quality (i.e. how much noise there is). Actually, opening it now, I see there has been an update and it has gained two new indicators. Used it multiple times to find APs. Also works on laptops (though a smartphone is much more handy to walk around with).
- tlow 10y agoDo you have suggestions for organizing semi-dense apartment complexes such that there aren't more SSIDs than units and are there legal ways to safely share wifi with neighbors? It seems to me that most TOS agreements from ISPs seem to not like the idea that I might share my wifi with my neighbors... Also comments on 20 MHZ v 40 MHZ routers? For high latency, highly attenuated signal situations where varies from .1 Mbps to 3 Mbps, on OSX should one mess with MTU? Last unrelated tangent, how far are we until we can expect to start seeing widerspread municipal wifi deployments? Is it possible that school districts might expect to see 100% home internet penetration in a non-trivial percentage of American school district areas?
- kopijahe 10y agoIn topic of building a multi-AP but with same SSID wifi network: Do I choose the same channel too or not? I have a wifi networks on a building built with brick and mortar, so I need more APs to cover the entire premise, there gonna be some overlaps in the coverage here and there...
- hunter2_ 10y agoNo, set every AP to use the quietest channel. Using something like Wifi Analyzer on a phone positioned where the AP will be but with the AP off, see what's got the least going on... any loud APs on the same channel whether they're yours or not would be detrimental. Also completely avoid overlap. On 2.4 GHz that means 1, 6, 11. Also, if there will be so many APs that they will share channels, you want the APs physically isolated from each other even if that means a little more isolation between AP and client than you'd otherwise have. For example, in a hotel or dorm put an AP in every third room instead of all in the hallway, so they don't hear each other.
- el_isma 10y agoSome APs let's you lower transmit power, which will help in isolating them