[AusNOG] NBN Satellite Latency

[Greg McLennan]

My typical pings for a geostationary global link I manage(melb to asia) from rf modem to rf modem(comtech) ~530ms. But expect to see slightly longer ping timed if say the bird is low on the horizon(e.g you at around 18 degrees elevation to see the satellite) for the ground station antenna compared to being located on the equator and pointing straight up.. You can do the physics math!!

Cheers Greg

Sent from my Samsung Galaxy Ace 3 on the Telstra 4G network

-------- Original message --------
From: Jonathan Brewer <jon.brewer at gmail.com> 
Date:03/02/2017  4:22 PM  (GMT+10:00) 
To: Paul Wilkins <paulwilkins369 at gmail.com> 
Cc: ausnog at lists.ausnog.net 
Subject: Re: [AusNOG] NBN Satellite Latency 

On 3 February 2017 at 18:39, Paul Wilkins <paulwilkins369 at gmail.com> wrote:
Which is 460ms, almost double what you pay Einstein (240ms). Wonder where it all goes? They would have to be using TDM, because only a time slot delay is going to make that sort of difference. 700ms is pretty awful.

460 is a bit light for what you pay for your speed of light journey, not double.

Your request goes up 35,786 km, and that takes... 119.3ms
It comes down from the satellite to the earth station, 119.3ms
If all goes perfectly (you land at your content) you spend 1ms on the ground.
Your reply goes up to the satellite, 119.3ms
Your reply comes down from the satellite, 119.3ms

Einstein says the best you're going to do is 478 ms.

700 isn't great and I kind of doubt that's normal based on my observations. Best get some real data from someone who is measuring it in a controlled fashion before you have a whinge about it being awful.

-JB




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ausnog.net/pipermail/ausnog/attachments/20170203/5ac2ccb1/attachment.html>