0:00:00.260,0:00:02.870 One of the surprising things about network speed is that a 0:00:02.870,0:00:05.100 lot of what determines the end to end speed of a 0:00:05.100,0:00:08.560 network in practice is not the throughput, how fast you can 0:00:08.560,0:00:11.730 push bits through the channel, but the latency, the time it takes 0:00:11.730,0:00:14.240 to get a response from the other end. Let's take a 0:00:14.240,0:00:19.130 look at where that latency comes from. For each HTTP request, even 0:00:19.130,0:00:22.070 after we've gotten the radio to wake up, we have to 0:00:22.070,0:00:25.420 do a DNS lookup to figure out what that domain name server 0:00:25.420,0:00:28.100 actually means in terms of IP number. We have 0:00:28.100,0:00:30.830 to make a socket connection to that site. We 0:00:30.830,0:00:33.920 have to actually send the HTTP request and then 0:00:33.920,0:00:36.120 we actually get our data back. Each one of 0:00:36.120,0:00:39.990 these steps takes time. On an LTE network, each 0:00:39.990,0:00:43.480 one of these requests takes between 240 and 500 0:00:43.480,0:00:46.270 milliseconds, depending on whether we already have a connection 0:00:46.270,0:00:50.680 going or not. On 3G, each request will take 600 0:00:50.680,0:00:56.280 milliseconds to 3.5 seconds, that's per every HTTP request.