bbs wastes a lot of bandwidth.
Suppose two people
are discussing one topic on a non-threaded board, to see any new message,
each one has to refresh the whole page (which contains all the messages
in one flat file), assume average message size is S, and there are
N messages in the topic, the amount of traffic (T) generated by each
person is at least
T = 1S+ 2S +
3S +.... +NS = (1+N)*N*S/2 ~ N*N*S /2
are 20 messages in the topic and average message size is 5k, we have
T = 20*20*5/2 = 1000K ~ 1MB
This is the minimum
traffic per person in order to finish this topic (20 messages), the
actual number might be several times higher, why? Because the person
does not know whether a new reply is posted, and he/she has to repeatedly
download this growing page to see if there are new messages, even
if the server replies with 304, there is a still a >1 multiplier
to this 1MB number.
is one lengthy post in the topic, and the rests are short comments,
what happens? To see those additional comments, one has to download
the long one many times.
What about a
threaded message board?
In this case,
each message is in a separate html file. To see new posts, the user
reloads the main index page, which lists links to new posts. A user
visit each message exactly once, to finish the 20 post discussion,
a user download 5*20 = 100 (kb), which is 10% of the non-threaded
Of course, a
topic in a non-threaded board rarelly goes beyond 20 messages, and
a threaded topic can grow to hundreds of messages.
site has a 10GB traffic allowance/month, how many page views can a
non-threaded and a threaded message board generate at maximum, respectively?
The answer can
be found easily, simply divide 10GB by the file size of each type
of the boards.
For a threaded
board, it is 10 * 10^9 / (5* 10^3) = 2 * 10 ^6 = 2 Million page views
For a non-threaded
board, it is 10 * 10^9 / (100 * 10^3) = 10^5 = 100,000 page views