MQTT通信数据包格式
时间: 2023-11-11 19:03:46 浏览: 31
MQTT通信数据包格式如下:
1. 连接请求报文格式:
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |
| 2 | 0 | 6 |
| 3-8 | M | Q | I | s | d | p |
| 9 | 4 |
| 10-11 | 0 | 60 |
| 12-13 | 0 | 16 |
2. 发布报文格式:
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 0 | 0 | 0 | 1 | 1 | 0 | d | QoS |
| 2-3 | MSB Length | LSB Length |
| 4-5 | MSB Topic | LSB Topic |
| 6-... | Topic | Payload |
3. 订阅报文格式:
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 |
| 2-3 | MSB Message ID | LSB Message ID |
| 4-... | Subscription List |
4. 取消订阅报文格式:
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 |
| 2-3 | MSB Message ID | LSB Message ID |
| 4-... | Unsubscription List |
5. 断开连接报文格式:
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
| 2 | 0 | 0 |
以上是MQTT通信数据包的格式,其中每个字段的含义和用途可以参考MQTT协议的详细规范。