Sniff Wi-Fi

Prime Video's stream of the 49ers-Cardinals NFL game received plenty of bad reviews on social media. While most of the negativity focused on stream quality, Wi-Fi largely escaped blame. There is one application type that confounds networks above all others, and it is live video. Pick your poison: voice, location tracking, on-demand video, cloud-hosted apps... None of them cause problems as consistently or predictably as the livestream. The issue is a simple one: broadcast vs. two-way. Packetized data networks are a two-way communication medium. Receiver must acknowledge sender. Live video has, since its inception decades ago, been a broadcast technology. Your television doesn't send anything to the local broadcast tower. Same with cable boxes. Same with satellite dishes. Pushing against this immutable scientific fact is commerce. Sports leagues see the billions of dollars being spent by streaming services, and they want some. Streaming services see the millions of eyeballs tun

If I sound a little bit surly today, it's because I spent last night watching this: For those who don't follow basketball, that's the brilliant Nikola Jokic (likely named in honor of wireless pioneer Nikola Tesla !) dissecting my beloved Milwaukee Bucks . If the result of the game -- the Bucks losing by 11 points in Milwaukee -- didn't make me surly on its own, my Wi-Fi experience yesterday surely didn't help.  The Wi-Fi in the Southwest Airlines terminal at LAX was slow and unstable, and the Wi-Fi at the aforementioned game (held at the 18,717 capacity Bradley Center) was mostly unusable in the seating bowl.  But what good does it do to stay surly?  Instead, I'll offer some tips on getting Wi-Fi working at high occupancy spaces. High occupancy Wi-Fi is a sensitive issue for me for two reasons: 1) I'm sick of fixing high occupancy deployments, and 2) As a frequenter of high occupancy areas, I'm sick of bad Wi-Fi in those areas. The trouble i

Two years ago tomorrow Apple introduced the iPhone 5.  It was a big deal.  It was a big deal for gadget folks who wanted a bigger iPhone.  It was a big deal for wireless LAN folks who wanted users to use smartphones with speedier WiFi.   Now the iPhone 6 has been announced and it appears to be more of the same.  Gadgeteers get their bigger iPhone.  Wireless folks get their faster speeds.  Problem is, the faster wireless speeds likely won't mean anything for high capacity wireless deployments. The big news about the iPhone 6 is 802.11ac.  Yippee!  Apple has finally adopted the latest and greatest WiFi standard in a mobile device. 802.11ac has data rates as high as 6.9 Gbps in the standard, but wireless LAN folks know that's not what happens in real life.  Real 802.11ac devices top out at a 1.3 Gbps data rate when multiple input-multiple output (MIMO) antenna systems are supported, while non-MIMO devices top out at 433 Mbps. The iPhone 6 and iPhone 6 Plus are non-MIMO 8

I defend Apple a lot.  When Network World wrongly accused  the original iPhone of flooding Duke University's network, I defended Apple .  (It was later found to be a Cisco problem.)  When a health care provider I was doing some work for blamed SIP-enabled iPhones for a VoIP problem, I eventually found out that the APs were to blame .  (The APs were failing to respond to WiFi frames tagged as "Background" QoS.)  Time and time again networking folks blame device makers like Apple, and time and time again the problem ends up being the network. There are times, however, when it really is Apple's fault.  When the network is operating just fine.  This is one of those times.  The problem is that I just don't know why. 802.11n (HT) and 802.11ac (VHT) networks operate in co-existence with first generation (802.11a/b/g, that is) WiFi a lot.  When that happens, the HT or VHT access point operates in mixed mode. There are all sorts of ramifications when a WiFi network