jdev - 2026-08-09

Should a client send a whitespace as a keep alive check or is that more of a server thing? And if yes, what is an optimal time interval to do it?

you can and the optimal time depends entirely on your specific device attributes and connection

https://xmpp.org/extensions/xep-0286.html is worth a look

but iirc 5g is totally different and many things needed for 3g are harmful with 5g and vice-versa 💀

It shouldn't be needed in general, but in some environments connections are aggressively closed, so the client will send 'something' just so the connection appears active - in that case, you'll have to check how aggressively they're closed (every few minutes should be enough); using XEP-0198 (Stream Management) is a good idea anyway

I recently had to start doing "something" on my 5g or one direction of the TCP closed which caused bonkers results

the best solution is to avoid TCP and all those nasty middleboxes that can close connections by just using QUIC

but of course you'll still need to support legacy TCP for some years yet

I'm sure the CGNAT people will find ways to fuck up quic also

ISPs are so goddamn annoying

"Let us optimize our bandwidth usage by closing connections early, making clients waste more bandwidth on handshakes and shit"

> I recently had to start doing "something" on my 5g or one direction of the TCP closed which caused bonkers results I remember when the TCP RST flag was made to fix issues with clients sending stuff to already-closed connections ↺

Then ISPs abused it to close whatever connections whenever they wanted