[LINK] The PLAN, and broadband speeds?

Richard Chirgwin rchirgwin at ozemail.com.au
Fri Jun 29 06:57:33 AEST 2007


Saliya Wimalaratne wrote:
> On Thu, Jun 28, 2007 at 07:26:08AM +1000, Richard Chirgwin wrote:
>   
>> Saliya Wimalaratne wrote:
>>
>> [snip]
>>     
>>> For geostationary satellite, the delay is about 450ms (one-way sat, one-way
>>> terrestrial) or about 1000ms (two-way sat). 
>>>  
>>>       
>> 'Scuse me, but 270 milliseconds both ways.
>>     
>
> You're excused, because I'm talking about real-world measured 
> performance of a few dozen user accounts here, not a calculation 
> of what it might possibly be under ideal 
> conditions :) This data was collected and averaged a few years ago
> and I have no doubt that things are _better_ now - perhaps someone
> would like to collect current data? 
>   
...Sal, the "real world" test is including all aspects of the end-to-end 
link (ie, routing etc). It must; because the speed of light certainly 
didn't change in the last few years... :-)

The reason I'm indulging in being pedantic is because all IP comms 
suffer latency and delay in routing; it's inappropriate to compare:

A) End-to-end session delay in satellite; vs
B) Physical layer delay only in ADSL.

Cheers,
RC
> Regards,
>
> Saliya
>
>   



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