Re: Practical guide to predicting latency effects?

[Eric Tykwinski <eric-list () truenet com>]

There is still one in XCode tools.  It’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 it’s there.

Sincerely,

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

> On Apr 8, 2020, at 10:33 PM, Lee <ler762 () gmail com> wrote:
>
> On 4/7/20, Adam Thompson <athompson () merlin mb ca> wrote:
> > I’m looking for a practical guide – i.e. specifically NOT an academic paper,
> > thanks anyway – to predicting the effect of increased (or decreased) latency
> > on my user’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 – we have the usual north-american
> > duopoly on last-mile consumer internet here; I’m connected directly to only
> > one of the two.  There’s a cost $X to improve connectivity so I’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 () merlin mb ca<mailto:athompson () merlin mb ca>
> > www.merlin.mb.ca<http://www.merlin.mb.ca/>