If the payload is larger than or equal to
224−1 bytes the length is set
to 224−1 (ff ff
ff) and a additional packets are sent with the rest
of the payload until the payload of a packet is less than
224−1 bytes.
Sending a payload of 16 777 215 (224−1) bytes looks like:
ff ff ff 00 ... 00 00 00 01