[TwoBit]

Probably just means the encrypted messages are in holding on the server until delivered. There's not much alternative to that unless peers are enabled to talk directly to each other, which would likely be a poor experience due to reliability and connectivity issues.

[vlovich123]

It would probably be much more ideal to have peers send messages to each other directly & only use the server for store + forward if the send fails.

[paxys]

True P2P isn't really possible today in the vast majority of ISP networks (especially mobile ones), so at most traffic will be relayed by a TURN server which is also centralized.

[vlovich123]

Are you sure that mobile networks really go out of their way to block STUN, not to mention that they’re predominantly IPV6 so the reasons for NAT would be weird at the carrier level (haven’t investigated this too thoroughly so not sure).

[bzb5]

It is not the nineties anymore, everybody is behind at least one NAT. Especially mobile phones.

[cesarb]

On the other hand, mobile phones often also have an IPv6 address, which is not behind a NAT.

[GekkePrutser]

It would be good in some ways but could cause tracking by malicious peers by becoming aware of the target's ip address

[dTal]

That would require at least a retry, which might fail if the sender also has a spotty connection. One of WhatsApp's main deliverables is reliable service over bad connections.

[danielheath]

That assumes that you want your phone radio running at full power 100% of the time, which would drain your battery in about 2 hours.