QoS 1 outbound flow state (server → client).
Server sends PUBLISH → awaits PUBACK from client.
Readonly
The PUBLISH packet being tracked.
Packet identifier.
Number of retransmission attempts.
Timestamp when the packet was sent.
Flow type discriminator.
QoS 1 outbound flow state (server → client).
Server sends PUBLISH → awaits PUBACK from client.