How to determine WebRTC dataChannel.send is delivered?

[jimmywarting]

I was searching for a way to determinate if a message have been delivered.
So i was investigating ACK message, and sending reply and doing some kind of RPC callback jank

but then i found this:
https://stackoverflow.com/questions/58256552/how-to-determine-webrtc-datachannel-send-is-delivered

You may not need to, if you use an ordered, reliable datachannel (which is the default).

An ordered reliable datachannel
With one of these, you determine a message was sent, by waiting for the bufferedAmount to go down:

I just want to be sure about one thing: if i use ordered and reliable, Will bufferedamount only decrease once the receiver have received the message?

meaning: it's not the underlying OS that actually sends the message over the network that decreases it... it's the receiver who says that?

[xenovation]

Just wanted to share some details regarding bufferedAmount if someone else came here from search engine, during my testing in chrome, for both ordered/unordered, reliable channel, after initiating a send, the bufferedAmount will increase and then immediately go down even if the data has not been sent yet, unless if the internal buffer of sctp is full (which is around 3MB), then bufferedAmount will start piling up.