A PUBREC Packet is the response to a PUBLISH Packet with QoS 2. It is the second packet of the QoS 2 protocol exchange.
This contains the Packet Identifier from the PUBLISH Packet that is being acknowledged.
See Implementation
A PUBREC Packet is the response to a PUBLISH Packet with QoS 2. It is the second packet of the QoS 2 protocol exchange.