MQTT-3.1.1-CN 5
3.4.4 动作 ........................................................................................................................................... 34
3.5 PUBREC – 发布收到(QoS 2,第一步) ........................................................................................ 34
3.5.1 固定报头 .................................................................................................................................... 34
3.5.2 可变报头 .................................................................................................................................... 34
3.5.3 有效载荷 .................................................................................................................................... 35
3.5.4 动作 ........................................................................................................................................... 35
3.6 PUBREL – 发布释放(QoS 2,第二步) ......................................................................................... 35
3.6.1 固定报头 .................................................................................................................................... 35
3.6.2 可变报头 .................................................................................................................................... 35
3.6.3 有效载荷 .................................................................................................................................... 36
3.6.4 动作 ........................................................................................................................................... 36
3.7 PUBCOMP – 发布完成(QoS 2,第三步) ..................................................................................... 36
3.7.1 固定报头 .................................................................................................................................... 36
3.7.2 可变报头 .................................................................................................................................... 36
3.7.3 有效载荷 .................................................................................................................................... 36
3.7.4 动作 ........................................................................................................................................... 36
3.8 SUBSCRIBE - 订阅主题 ................................................................................................................... 37
3.8.1 固定报头 .................................................................................................................................... 37
3.8.2 可变报头 .................................................................................................................................... 37
3.8.3 有效载荷 .................................................................................................................................... 37
3.8.4 响应 ........................................................................................................................................... 39
3.9 SUBACK – 订阅确认 ......................................................................................................................... 40
3.9.1 固定报头 .................................................................................................................................... 40
3.9.2 可变报头 .................................................................................................................................... 40
3.9.3 有效载荷 .................................................................................................................................... 41
3.10 UNSUBSCRIBE –取消订阅 ............................................................................................................ 41
3.10.1 固定报头 .................................................................................................................................. 42
3.10.2 可变报头 .................................................................................................................................. 42
3.10.3 有效载荷 .................................................................................................................................. 42
3.10.4 响应 ......................................................................................................................................... 43
3.11 UNSUBACK – 取消订阅确认 .......................................................................................................... 43
3.11.1 固定报头 .................................................................................................................................. 44
3.11.2 可变报头 .................................................................................................................................. 44
3.11.3 有效载荷 .................................................................................................................................. 44
3.12 PINGREQ – 心跳请求 ..................................................................................................................... 44
3.12.1 固定报头 .................................................................................................................................. 44
3.12.2 可变报头 .................................................................................................................................. 45
3.12.3 有效载荷 .................................................................................................................................. 45
3.12.4 响应 ......................................................................................................................................... 45
3.13 PINGRESP – 心跳响应 ................................................................................................................... 45
3.13.1 固定报头 .................................................................................................................................. 45