Satelite Internet Latency

I have a Tp-Link Archer C60 V3 rooter with OpenWrt installed and connected to a satelite for internet. Is there any change that the latency can be improved or for better response, especially for playing games online. Thanks

I assume you mean a geo-stationary satellite.
There is very little you can do to improve latency in a satellite connection.
The distance from your dish to the satellite is 36.000 kilometers; the speed of light is 300.000 km/s. This means that a message sent from your router takes 120ms just to reach the satellite; another 120 ms are required for the satellite to forward the message to the ground station; another 120+120 for the message to be received back by your receiver.

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Not much you can do about the speed of light. What you may be able to do is keep that latency constant (round trip time ~ 500 to 600ms). If you experience bufferbloat on a high latency link it could become VERY painful, with delays of 5 to 10 seconds being not out of the question.

But I doubt you'll ever be able to really play games on a satellite link

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Thanks, yeah I saw the latency is about 600ms. Watching movies or live tv is no problem, only games I play. Feels like its about a second behind, but its that second that counts.

Most gamers obsess about a few (dozens) ms, so I am not sure any fast reaction based game will work competitively over geo-stationary satellites, unless all players sit behind such links.
That said, in case you want to try sqm (which will not help much) you should adjust sqm's interval value, if you want to try that, please holler, and I will help you get things set up (but as I said, at the base latency, all sqm can do for you is manage your "pain" a bit it is no cure for GEO links)

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Yes please assist. I also have a outdoor rooter connected to the rooter via wireless repeater and for some reason if connected to it, it seems faster playing online game on my phone, dont know why.

On the countryside I used to have a satelite link and there is nothing you can do to improve latency. I never was able to go below 600 ms. Try connecting with 4G with your phone connected to USB and route all game trafic to your phone if you can.

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Thanks ffries, but unfortunately in my area there is no 4g or even 3g coverage😒, no fibre no adsl🙃

Bad luck. In my area in France, coverage with ADSL was so poor and roten that they decided 10 years ago to invest in fiber. They brought a 6 km fiber wire up to my house. Now on the countryside in my area, we all have fiber. Fiber is the only long-term solution for rural erea.

It is a very lucrative market for ISPs because 99% of consumers are buying fiber.

Maybe Elon Musk can solve your problem of satelite latency. The new generation of satelites will operate in low altitude. I think it is a technology of the past as nothing beats fiber on the long run.

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Okay. Let's see.

I would start with installing sqm-scripts and luci-app-sqm (unless you did that already):

opkg update
opkg install sqm-scripts luci-app-sqm nano

(the nano editor is optional, but it makes modifying /etc/config/sqm on the router somewhat easier than the default vi-compatible editor, feel free to not install that if you are fluent in vi :wink: )

Next you need a reasonably complete config file, just edit your /etc/config/sqm to read (that is do not delete existing lines, but either edit them to match my proposal or add them completely if they are missing):

	option ingress_ecn 'ECN'
	option egress_ecn 'NOECN'
	option qdisc 'cake'
	option script 'layer_cake.qos'
	option qdisc_advanced '1'
	option qdisc_really_really_advanced '1'
	option eqdisc_opts 'nat dual-srchost rtt 600ms'
	option linklayer 'ethernet'
	option overhead '38'
	option linklayer_advanced '1'
	option tcMTU '2047'
	option tcTSIZE '128'
	option tcMPU '64'
	option linklayer_adaptation_mechanism 'default'
	option debug_logging '1'
	option enabled '1'
	option iqdisc_opts 'nat dual-dsthost ingress rtt 600ms'

The actual overhead value (38) is just guess work and will need some testing/confirmation later, for upload and download enter (as first approximation) the upload and download you can reliably get in speedtests (make sure to convert these results into kilobits per second as that is the unit sqm requires). Once you done that post a speedtest result from before and after (that is with sqm enabled and disabled, you can use /etc/init.d/sqm stop and /etc/init.d/sqm start to anually disable/enable sqm from the command line, or use the enable checkbox in the luci gui (click save and apply after toggling this)).
But as before this is not guranteed to actually help, so some testing might be required, if latency is more important than throughput, you can change the rtt 600ms parts to lower values.

Good luck!

Good call, see https://arstechnica.com/information-technology/2020/08/spacex-starlink-beta-tests-show-speeds-up-to-60mbps-latency-as-low-as-31ms/ for very preliminary numbers.

IMHO, if you also want to speed up web browsing, you also need a proxy to cache recursive files. I could achieve 600 ms using a proxy. Okay, this does not apply to your gaming problem, but who knows.

Speedtest should always be done in full-charge.

I am very pessimistic with satelites in general, especially because many users will be using the same frequency, which by design drops bandwidth.

The same applies with WIFI when several users and APs are sharing the same congested channel.

I have no first hand experience, so please indulge my naivety, does that still work with https? A proxy seems like a good idea, as that would allow to tune the TCP stack for the high RTT...

Good point, https cannot be cached in proxy. I used satelite more than 10 years ago. At that time, https was not so common.

The problem with satelites is that when transmission is chained, you have to wait 200-300ms on each chain. I recall waiting 2 or 3 seconds for a tiny webpage. You need http3 to go fast, but i am not sure.

Anyway, satelite is a technology of the past.

Quite a few, but not all, https-sites can be cached. Needs special cert to be installed on client, then. And quite some learning about squid.

Good point, you need to generate your certs and install them in the proxy. Called https interception. Some governments with access to root CAs are doing that too ...

Again i never was able to go below 600ms even on a casual http website with satelite.

My satellite dish with microwave transmission ended in recycling, and I was not even able to give it for free as nobody ever wanted to pick it up (we all had fibre).

Good luck Elon Musk.

Modern satellite systems employ many different tricks to get around this problem. With our new(ish) satellite system down here in Australia there is equipment at the PoI (point of interconnect) which helps to speed up web page load times by pre-fetching the rest of the page so that it can be delivered in one chunk to the end user.

The end user does see an initial delay but once the page starts ot come in it all comes in pretty quickly.

No good for real time stuff though obviously still.

But your still looking at the same latency. Same thing here. It grinds away on a blank screen ad infinitum, and then bam - instant page load. It gets worse when they start traffic management in peak periods (24/7 apparently) which favours voip, social, browsing - bad news for anything else. SQM has been fruitless - nothing so far has improved latencies.

As the highest point geographically, I’m outside any wifi fresnel zones. There are redundant fibre lines running 1.2 Km away that trunks off to my side road. The trunk stops 600 meters away and cannot run the “last mile” due to regulatory issues with co-location. I even tried to get the trunk provider to supply me with a repeater and double tap and I’d pay for and run the RG11 - no return for them short term so no go. Talk about frustration.

I could go on and on, but I digress, and it’s not really conducive to the question.

@SteMax97 says it best.

I’ve been following Spacex since they launched the low-orbit arrays and when I found I’m in the beta lat/long, signed up using my geolocation. Personally, I think he has a quite viable solution to funding his Mars project. If he can give me 23ms vs 650-3524ms I’m in.

Welcome to Black Hole Hell. Unfortunately, I can’t offer anything that might help to improve your situation. 653ms seems to be my magic number. I’ve yet to improve on that despite some mighty effort. Without space/time bending becoming reality we’re pretty well stuck where we are.

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I confirm 600 ms was the bottline for me too.