mirror of
https://github.com/mcxiaoke/mqtt.git
synced 2026-02-07 23:20:43 +08:00
@@ -8,11 +8,42 @@ PUBLISH控制报文是指从客户端向服务端或者服务端向客户端传
|
||||
|
||||
##### 图例 3.10 – PUBLISH报文固定报头
|
||||
|
||||
| **Bit** | **7** | **6** | **5** | **4** | **3** | **2** | **1** | **0** |
|
||||
|---------|----------------------|-------|---------|--------|-------|-------|-------|-------|
|
||||
| byte 1 | MQTT控制报文类型 (3) | | | | DUP | QoS-H | QoS- | RETAIN|
|
||||
| | 0 | 0 | 1 | 1 | | | | |
|
||||
| byte 2 | 剩余长度 |
|
||||
<table style="text-align:center">
|
||||
<tr>
|
||||
<td align="center"><strong>Bit</strong></td>
|
||||
<td align="center"><strong>7</strong></td>
|
||||
<td align="center"><strong>6</strong></td>
|
||||
<td align="center"><strong>5</strong></td>
|
||||
<td align="center"><strong>4</strong></td>
|
||||
<td align="center"><strong>3</strong></td>
|
||||
<td align="center"><strong>2</strong></td>
|
||||
<td align="center"><strong>1</strong></td>
|
||||
<td align="center"><strong>0</strong></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>byte 1</td>
|
||||
<td colspan="4" align="center"> MQTT控制报文类型 (3)</td>
|
||||
<td align="center">DUP</td>
|
||||
<td align="center">QoS-H</td>
|
||||
<td align="center">QoS-</td>
|
||||
<td align="center">RETAIN</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td></td>
|
||||
<td align="center">0</td>
|
||||
<td align="center">0</td>
|
||||
<td align="center">1</td>
|
||||
<td align="center">1</td>
|
||||
<td align="center">X</td>
|
||||
<td align="center">X</td>
|
||||
<td align="center">X</td>
|
||||
<td align="center">X</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>byte 2...</td>
|
||||
<td colspan="8" align="center">剩余长度</td>
|
||||
</tr>
|
||||
</table>
|
||||
|
||||
#### 重发标志 DUP
|
||||
|
||||
|
||||
Reference in New Issue
Block a user