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Practical guide to predicting latency effects?



There is still one in XCode tools.  Itâ??s a alternate download: https://developer.apple.com/download/more/?q=Additional%20Tools%20for%20Xcode <https://developer.apple.com/download/more/?q=Additional%20Tools%20for%20Xcode>
Of course this is limited to OSX, but itâ??s there.

Sincerely,

Eric Tykwinski
TrueNet, Inc.
P: 610-429-8300

> On Apr 8, 2020, at 10:33 PM, Lee <ler762 at gmail.com> wrote:
> 
> On 4/7/20, Adam Thompson <athompson at merlin.mb.ca> wrote:
>> Iâ??m looking for a practical guide â?? i.e. specifically NOT an academic paper,
>> thanks anyway â?? to predicting the effect of increased (or decreased) latency
>> on my userâ??s applications.
>> 
>> Specifically, I want to estimate how much improvement there will be in
>> {bandwidth, application XYZ responsiveness, protocol ABC goodput, whatever}
>> if I decrease the RTT between the user and the server by 10msec, or by
>> 20msec, or by 40msec.
>> 
>> My googling has come up with lots of research articles discussing
>> theoretical frameworks for figuring this out, but nothing concrete in terms
>> of a calculator or even a rule-of-thumb.
> 
> There used to be network simulators that claimed to figure that out for you - eg
> https://opnetmodeler.wordpress.com/
>  "Predict application performance using real traffic in a simulated mode"
> 
> I suspect all that died after encryption became the norm, since you
> have to be able to see and understand what's going on before you can
> predict what will happen after changing the network.  Take a look at
> https://www.cse.wustl.edu/~jain/cse567-08/ftp/simtools/index.html
>  the date is 2008 and all the references are http://xxx  (or maybe I
> can't search worth beans & missed all the current references)
> 
> Or maybe simulation just got too expensive?  I vaguely recall sitting
> through a few OPNET sales pitches in the early 2000s & people getting
> excited about the product until they found out how much it cost :(
> 
> Regards,
> Lee
> 
> 
>> 
>> Ultimately, this goes into MY calculator â?? we have the usual north-american
>> duopoly on last-mile consumer internet here; Iâ??m connected directly to only
>> one of the two.  Thereâ??s a cost $X to improve connectivity so Iâ??m peered
>> with both, how do I tell if it will be worthwhile?
>> 
>> Anyone got anything at all that might help me?
>> 
>> Thanks in advance,
>> -Adam
>> 
>> Adam Thompson
>> Consultant, Infrastructure Services
>> [[MERLIN LOGO]]<https://www.merlin.mb.ca/>
>> 100 - 135 Innovation Drive
>> Winnipeg, MB, R3T 6A8
>> (204) 977-6824 or 1-800-430-6404 (MB only)
>> athompson at merlin.mb.ca<mailto:athompson at merlin.mb.ca>
>> www.merlin.mb.ca<http://www.merlin.mb.ca/>
>> 
>> 

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