Just to be factual correct: implementations can retransmit lost packets also without RTX. Otherwise calls with Firefox on other services would hang all the time, which they don't. Jitsi favors RTX for retransmissions, and as you can see in the Firefox bug integrating the feature into non-Chrome browsers is challenging.
[^] # Re: Bien d'accord !
Posté par antistress (site web personnel) . En réponse au journal Jitsi dénigre Firefox et décrédibilise des logiciels libres. Évalué à 3.
https://github.com/jitsi/jitsi-meet/issues/4758#issuecomment-605322725