On Sun, Jul 8, 2012 at 1:32 PM, Andrew S. Baker <[email protected]> wrote: > >> I would have thought that 1.5mbps is fine for a 3-4 person office. > > Not any more... :) > > If it were just increased file sizes, it would be one thing, but almost > every web page requires 10x the number of transactions as compared to > previous years.
And transactions (rather than size) are one of those areas that latency kills. First you have to establish a TCP connection to each web server. Each of those requires three one-way path traversals (SYN, SYN ACK, ACK). Then you have to send the HTTP request (another traversal). Only then does data start flowing, and it has to traverse the path before it hits you. So if the latency is symmetrical, turnaround before content starts arriving with HTTP is 2.5 times RTT (round-trip-time, AKA "ping time"). On a cell phone connection, RTT is often 150-300 ms. So now we're talking almost one full second before each resource on a web page starts loading. If those resources in turn request other resources, the problem becomes recursive. It may be several seconds before everything can even *start* transferring. And HTTP is relatively latency friendly compared to some things. -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to [email protected] with the body: unsubscribe ntsysadmin
