Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

KDE Connect: Enabling communication between all your devices

community.kde.org

Post reply on HN
Print view View original

151–160 of 208 posts

Re: KDE Connect: Enabling communication between all your devices

#151

Post by jeroenhd »

gear54rus wrote: post #145
ezst wrote: post #114

Earlier quoted context omitted.

> self-hostable coordination server What a long way to spell VPN :-) (been using it for a decade or so through wireguard)

No, vpn takes over your network and you have to fight weird issues on different platforms. This seems like a square peg for a round hole.

Wireguard is purely point-to-point. You have to manually specify any configuration involving routing more than just the local IP addresses you add.

Not sure if it's the best solution, but there's no reason to take over your entire network.

Even with my old OpenVPN setup I had a config where only my local 10.2.0.0/16 got routed over the VPN, everything else went straight to the outside world. Set up IPv6 ULA and you don't need to worry about IP addressing conflicts.

Re: KDE Connect: Enabling communication between all your devices

#152

Post by forbiddenlake »

exdeejay_ wrote: post #98
gear54rus wrote: post #70

Earlier quoted context omitted.

I definitely have a need for this, but I can't stomach same-network requirement. Maybe they need self-hostable coordination server so that devices can connect to each other through it. For now it's still 'send to telegram saved messages' for me.

Have you considered using Tailscale to get around the same-network requirement?

Tailscale doesn't support mDNS / multicast at all, making working with KDE Connect more nebulous. I attempted to add a static peer via the Tailscale hostname, but both ends report not reachable, and the Tailscale daemon is constantly dropping multicast packets. So I'm not sure how this helps, but I also don't have a use case - if I'm on my laptop, my phone is on the same Wifi network 99% of the time.

Re: KDE Connect: Enabling communication between all your devices

#153

Post by eitally »

sombragris wrote: post #17

At least in my use case (as link between Android devices and both Linux/Win PCs) KDE Connect is a real killer app. It enabled seamless integration and saved me lots of hassle and time. It really should get more exposure. I see reports that it doesn't work. These are mostly for distros where Plasma is either rather old or taking a backseat after other environment (usually Gnome). I'm having great results with the late…

I had a use case that isn't the primary function of KDE Connect, but where KDE Connect worked well: file sharing from a Mac to an Android phone. I had no idea apps like KDE Connect existed and now I'm hooked.

That said, for my specific use case, Blip is a FAR superior option, and much lighter weight.

Re: KDE Connect: Enabling communication between all your devices

#154

Post by ValdikSS »

snthd wrote: post #140
ValdikSS wrote: post #129

Earlier quoted context omitted.

>* be battery efficient, it's 2025 people! It took a long time for me to prove that what KDE does negatively impact the battery life. https://bugs.kde.org/show_bug.cgi?id=441830 The other user even wrote a LD_PRELOAD hijacking library to not recompile the application every time https://github.com/max0x7ba/kdeconnect-powersave-keepalive

Fixed in "Remove custom keepalive intervals" merged 12 Aug 2024 https://invent.kde.org/network/kdeconnect-kde/-/merge_reques...

It improved the battery life but made the connection activity detection worse (the disconnected phone won't be detected for up to 2 hours), but I didn't complain anymore.

I initially set it to 5 minutes.

Re: KDE Connect: Enabling communication between all your devices

#155

Post by ValdikSS »

ndriscoll wrote: post #136
ValdikSS wrote: post #129

Earlier quoted context omitted.

>* be battery efficient, it's 2025 people! It took a long time for me to prove that what KDE does negatively impact the battery life. https://bugs.kde.org/show_bug.cgi?id=441830 The other user even wrote a LD_PRELOAD hijacking library to not recompile the application every time https://github.com/max0x7ba/kdeconnect-powersave-keepalive

A 5 second keepalive seems unnecessary, but does that actually impact battery life? How long does the device take to move in and out of powersave states? I'd think you'd be looking at maybe 20-40 microseconds of CPU time to handle the packet, so 0.0008% of the time awake due to this. Are other parts of the device just super slow at moving in and out of powersave states?

Yes, it has dramatic impact on the battery life.

Wi-Fi in lower power state, when it has nothing to respond to, disables power amplifier and only listens to incoming data. Some functions which are usually performed by the OS are offloaded on smartphones to the Wi-Fi chip, such as ARP/NDP replies, so it doesn't need to wake up a CPU to perform simple answers.

However with the constant keep-alive it has to both enable power amplifier and to wake up the CPU to send the reply that the socket is still alive.

I have a single-board computer with and old Mediatek chip (10 years old), and there Wi-Fi PA increases power consumption by 200mW. Another reporter in the ticket told that his smartphone works basically 1/2 of its common battery life with KDE Connect enabled.

Keep-alives (not necessary TCP keep alives, but any of this kind of packets) are the _MAIN_ reason for internet battery drain while idle, and are tricky to debug if you don't know where to look (Android lists it as "Android System" or "Phone Idle")

For example, Golang applications had 15 second keep alive until recently: https://github.com/golang/go/issues/48622. Imagine you've opened the website which uses golang web server/proxy and enabled notifications from it in the browser, which use WebSocket from the website itself. Now every time your CPU is woke up every 15 seconds until you close the page and notification channel is offloaded to google/mozilla servers. And remember: every TCP connection has its own 15-second Keep-Alive in different intervals, so it's more like 5-7 second CPU wakeup interval.

The same applies for VPN. When anybody say that anways-on VPN connection drains battery, that is 90% if the time is due to frequent keep-alive packets from the VPN server.

Everything above applies to cellular connection as well, it's the same principle.

Re: KDE Connect: Enabling communication between all your devices

#156

Post by ValdikSS »

roshin wrote: post #12

when it works it's amazing. but very often both my phone and laptop are connected to the same WiFi, yet kde connect can't see them. I can't figure out how to diagnose and solve that when it happens

The majority of desktop Wi-Fi cards/chipsets have buggy drivers that break mDNS discovery in one way or another.

To the point that I'd say that Wi-Fi drivers are the most offender in printer discovery problems, which also rely on mDNS.

Another issue that many mDNS applications, including KDE Connect, don't account on multi-interface setups and send respond to mDNS request using incorrect network interface: https://bugs.kde.org/show_bug.cgi?id=507972 / https://bugs.kde.org/show_bug.cgi?id=507954

Re: KDE Connect: Enabling communication between all your devices

#157

Post by ValdikSS »

Oxodao wrote: post #21
m463 wrote: post #18

Earlier quoted context omitted.

it also talks about using a VPN and what ports to open in a firewall. I don't know how it handles the harder part, the "device on internet" talks to "device in my house" most phones and apps use this "harder part" to interpose their corporate server for more than TURN/STUN and continue to "collect all the data" or "insert a subscription"

Did you get this to work with wireguard though? As long as my phone is connected to wireguard KDEConnect does NOT see any other computer, apparently because it wont forward ICMP broadcast according to the internet. I would really like to have a solution to this issue but since its baked in WG i don't think this is possible

>As long as my phone is connected to wireguard KDEConnect does NOT see any other computer, apparently because it wont forward ICMP broadcast according to the internet.

It's a bug in the application.

https://bugs.kde.org/show_bug.cgi?id=507954 / https://bugs.kde.org/show_bug.cgi?id=507972

Re: KDE Connect: Enabling communication between all your devices

#158

Post by troyvit »

maqnius wrote: post #88
Kim_Bruning wrote: post #6

This is a killer app. There have been times when I asked someone "why can't you just send me a screenshot on signal" or "Oh, can't you copy the URL to your desktop?"... only to realize that the poor fellow didn't have KDE connect (yet). It's not perfect, but it does things I haven't found anywhere else, makes your phone and laptop and pc. It might help that I'm actually running KDE everywhere, of course.

I have a all my messengers running on my desktop as well, so I don't really have those problems. How's KDE Connect superior? I'm seriously interested, since I read it's a killer feature but I cannot really imagine how it would help me.

Silly use case but I watch TV on my laptop in bed and the cat likes to watch with me. I use some ancient X11 app to freeze the keyboard and mouse and then control vlc, etc. from KDE-connect. That way when my cat attacks Jedis he doesn't reboot my laptop.

Re: KDE Connect: Enabling communication between all your devices

#159

Post by tasuki »

I've been using this and recently had a very unpleasant experience: it couldn't mount my new Chinese android phone (worked with the old one!) and the "send file" feature subtly renamed my files (from .tif to .tiff).

It cost me four hours (QField atrocious error messages) and I'm still angry about it.

Re: KDE Connect: Enabling communication between all your devices

#160

Post by lazycouchpotato »

roshin wrote: post #12

when it works it's amazing. but very often both my phone and laptop are connected to the same WiFi, yet kde connect can't see them. I can't figure out how to diagnose and solve that when it happens

At least for Windows, marking a WiFi connection from Public to Private solved a lot of connection issues for me.
Post reply on HN