I have some more information about load time (speed) variations for users:
While traveling with my notebook computer this week, I conected from a remote area to AlfaBB via a
Hughes Direcway broadband satellite link and encountered load times of 30 seconds or more for the
Forum Index page.
I took a
WireShark trace of a page refresh (using "F5" on IE 7) and took another trace of the same page when I got home (load times of about 6 seconds via Cable broadband). I was logged in in both cases (due to my subscription level I see less ads than non-paying subscribers).
Attached is an Excel file with a Side-by-Side comparison of elapsed time for the same page element requests (i.e those requests that were identical on both pages). I also included the raw traces of both traces. A few things are worth mentioning:
- Ping roundtrip time (RTT) to www.AlfaBB.com was 750-800 msec via satellite and 15-40 msec via cable.
- The longer RTT over satellite caused packet losses, packet duplication, duplicate ACKs, and some timeout conditions where requests (e.g. DNS queries for ad servers) were sent more than once.
- The computer was the same, but time-of-day was different. Variances stemming from ad servers are not accounted for, etc.
- That being said, the satellite connection trace has about 10% more packets than the cable connection trace.
Roundtrip delay (and possibly the number of hops between a client system and the AlfaBB and ad server hosts) seems to be the major culprit why pages load slow for some users. One can see how the elapsed time in the two traces diverges from the beginning and does so at a fairly constant rate. When I googled for latency, I found service level agreements that indicate worst-case delay between two routers in North America is about 45 msec and 90 msec for North America to Europe. Even with complicated pages like the one traced (with 50+ page element requests from various servers) this difference should not add a lot of delay. However, if the roundtrip time gets longer (e.g. via satellite) the load time increases substantially.
Therefore, I would suggest that everybody with slow load times checks (and posts here) their roundtrip time. Users of Microsoft Windows can check this easily by first typing "command" in the "Start->Run..." box and then typing "ping www.alfabb.com" in the DOS window that opens. In case the result consistently shows "Request timed out." your system or network uses a firewall that suppresses
ICMP traffic and the firewall must be configured to allow such traffic.