Thread: FBO's and WiFi
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  #20  
Old August 20th 03, 06:13 PM
Scott Lowrey
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Pete Zaitcev wrote in message ...
On Tue, 19 Aug 2003 21:13:35 -0700, Peter Duniho wrote:

500ms ping time minimum... So count on lots of lag...


Unless you are playing online computer games, you would never notice the
lag. Most Internet access is of the form "brief request for data,
followed by large amount of data returned". It'll take an extra
half-second for the data to show up, but that will generally be swamped by
the time it takes to actually generate and send the data, even at
broadband speeds.


This depends on how big the data piece is relative to the
starting handshake. Consider that TCP start-up involves
so-called 3-way handshake, and that many protocols have
a setup phase when client and server exchange messages
strictly in simplex, before bulk data transmission can commence.


Sorry for continuing an off-topic conversation and splitting hairs,
but....

"Lag" in the original poster's case, is actually referred to as
"latency" in the world of computer networking. Latency is defined as
the time it takes to set up and send a message, whereas bandwidth is
the rate at which data moves from point to point. Sat connections,
therefore, have a latency of 500ms (for example) plus the latency of
the system doing the send/receive.

Since all data is transported in TCP packets (in the case of Web
traffic), there is continual send AND receive on BOTH sides since TCP
requires acknowledgement of every packet on the part the of the
receiver (remember, TCP is a *reliable* protocol). Granted, the ACK
packets are much smaller than the data packets and most of the traffic
to a web browswer is downstream, but a high-latency network like
satellite will exhibit performance degradation during *all* phases of
a connection, not just startup.

Did I just restate what was already said? Sorry!

-Scott
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