C → S → C {type:'fack', from:…, to:…, name:…, nr:…, of:…}

fack – file chunk reception acknowledge. Inform sender file chunk was received, next chunk can be sent.

arguments:

• from - name of client sending the acknowledgement
• to - name of client sending the file
• name - name of file
• nr - sequential number of received chunk
• of - number of chunks constituting the file

optional arguments:

• c2c - client to client mode:
  • "yes": do not forward message through SIP, only through direct connection to another wrtc client connected to same server

file