Since I installed openwrt 19.07 on my router Archer C20, Whatsapp voice calls stopped working (drop instantly) when performed between Two phones while both of them are on internet from the same router network (i.e between my phone and my wife's phone when we are connected to the same openwrt router).
1- it's not a wifi problem, same problem occures when we are connected to the wifi extender (lan connected to the main openwrt router).
2- Whatsapp calls work well when only one phone is connected to the router but the other phone is on another source of internet (on mobile data for example or a friend in another city).
Ah, I thought you had a problem calling someone by whatsapp outside the router. Interestingly, I've never even tried that. Today I will try it and write the result.
I think you're asking whether WhatsApp voice calls were working well on the stock firmware when both phones are connected to the same router ?
The answer is Yes
Not working
The thing is that, inside home WhatsApp calls were working fine with the stock tp-link firmware. Never changed anything on the phones, what I've done is just installing openwrt on the router.
Can you guys please try to WhatsApp call someone connected to the same openwrt router you're connected to, and report back if you can hear each other ?
Is the problem symmetric ? Does it occur in the same way when the iphone xr calls P30, as it occurs the other way round ? Does it also affect video calls ?
If you want to spend the effort and dig in deeper, you might use a sniffing tool to see what is going on and compare the not working case with a working case. I have never done that, but
oh man I don't know what to say, may be because my wife's iPhone was able to call my P30 Pro perfectly on the stock router firmware I didn't think I have to change anything on it, and I was totally mistaken for not listening to you, sorry.
Problem solved guys, I just had to enable local network on the iPhone, thanks to all of you especially to pavelgl.