[KLUG Members] Any sattelite ISP that supports Linux?

[Robert G. Brown]

>>>With satellite you've just added roughly a couple of hundred thousand
>>>miles to your packets travel.  Even at the speed of light (and
>>>remember, "c" is the speed of light in a vacuum, atmosphere is slower)
>>>it takes awhile at those distances.
>>Actually, it's much less than a hundred thousand miles, though this
>>doesn't help the latency issue. Remember that outer space begins a scant
>>So your satellite is about 40,000 miles away (from you and its base
>>station, remember): more than 1.6 times the circumference of the Earth
>Right, with a strong emphasis on the "and" in "(from you ***and*** its
>base station, remember)".  So that's a minimum of ~80,000 miles round
>trip.  That is a bloody long ways to go.  And hopefully you've only got
>one hop to go (a safe assumption if the receiver is in the USA).  Then
>you've still got to be routed through a last mile land line to the
>telco's switch, then to an MAE, then to where you actually want to
>reach.  Those last steps can be painful enough using DSL! 

Actually, all this talk about distance and so forth doesn't amount to a
hill o'beans compared to some other factors about satellite communications 
that have not been brought up yet. Remember, 80,000 miles is just under
420 milliseconds transmission time, but when the packets arrive at the
ground station (especially the transmitting station), they are subject to 
other delays, which typically add 500 - 1200 ms to the packets life, and
sometime a good deal more.

Geosyncheonus orbit, for a single uplink-downling pair, is 47,000 miles,
or 210 ms. something like 96% of the traffic can be characterized this
way. At 210 ms, the packet is STILL in delay lines and buffers for that
(typical) 500-1200 ms at the ground stations....so the shortest part of
the trip is... the trip!

>If satellites were such a great bi-directional communication method, why
>are there fleets of submarines used to lay fiber cable across the ocean
>floor? 
There are a few reasons. First of all, different media compete. Fiber on
the Ocean Floor is always going to have volume over satellite through the
air, and fiber is going to be great for point-to-point communication, as
long as you can guarantee the security of the cable and the seaside 
stations. Sattelite is going to be the clear choice when you want to 
originate or receive anything where there's no infrastructure into which
you can plug (Uzbekistan, for example, a place of much more importance
due to recent events).
							Regards,
							---> RGB <---