链路层常见封装格式

洛克糖

<p class="MsoNormal" align="center" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center;"><b style="mso-bidi-font-weight: normal;"><span lang="ZH-CN" style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">链路层常见封装格式</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 14pt; COLOR: black;"><p></p></span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 21pt; TEXT-INDENT: -21pt; tab-stops: list 21.0pt; mso-list: l0 level1 lfo1;"><span style="FONT-FAMILY: Wingdings; mso-fareast-font-family: Wingdings; mso-bidi-font-family: Wingdings;"><span style="mso-list: Ignore;">n<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><span style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto;"><font face="Times New Roman">PPoE</font></span><span lang="ZH-CN" style="BACKGROUND: #d9d9d9; FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-shading: white; mso-pattern: gray-15 auto;">封装格式</span><span style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto;"><p></p></span></p><pre style="tab-stops: 45.8pt 91.6pt 118.5pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;"><span style="FONT-SIZE: 9pt;"><font face="宋体">+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<p></p></font></span></pre><pre style="tab-stops: 109.5pt 118.5pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;"><span style="FONT-SIZE: 9pt;"><font face="宋体">| DMAC (6)<span style="mso-spacerun: yes;">&nbsp;&nbsp; </span>| SMAC (6)<span style="mso-tab-count: 1;">
                                </span>| TYPE (2) |<p></p></font></span></pre><pre style="tab-stops: 45.8pt 91.6pt 118.5pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;"><span style="FONT-SIZE: 9pt;"><font face="宋体">+-+-+-+-+-+-+-+-+-+-+-+-+-<span style="mso-tab-count: 1;">
                                </span>+-+-+-+-+-+<p></p></font></span></pre><pre style="tab-stops: 45.8pt 91.6pt 118.5pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;"><span style="FONT-SIZE: 9pt;"><font face="宋体">+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<p></p></font></span></pre><pre style="tab-stops: 109.5pt 118.5pt 183.2pt 229.0pt 274.8pt 311.25pt 375.75pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;"><font face="宋体"><span style="FONT-SIZE: 9pt;">| </span><span style="FONT-SIZE: 9pt; COLOR: red;">VER</span><span style="FONT-SIZE: 9pt;"> /</span><span style="FONT-SIZE: 9pt; COLOR: red;"> TYPE (1) </span><span style="FONT-SIZE: 9pt;">|</span><span style="FONT-SIZE: 9pt; COLOR: red;"> CODE (1) </span><span style="FONT-SIZE: 9pt;">|</span><span style="FONT-SIZE: 9pt; COLOR: red;"> SESSION_ID (2) </span><span style="FONT-SIZE: 9pt;">| LENGTH (2) |<span style="mso-spacerun: yes;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>payload</span><span style="FONT-SIZE: 9pt; COLOR: red;"><span style="mso-tab-count: 1;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="FONT-SIZE: 9pt;">|<p></p></span></font></pre><pre style="tab-stops: 45.8pt 91.6pt 118.5pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;"><span style="FONT-SIZE: 9pt;"><font face="宋体">+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<p></p></font></span></pre><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="ZH-CN" style="FONT-SIZE: 9pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">红颜色</span><span lang="ZH-CN" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">标识的是</span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">PPoE<span lang="ZH-CN">帧头</span>,<span lang="ZH-CN">其中</span>VER<span lang="ZH-CN">和</span>TYPE<span lang="ZH-CN">字段各占</span>4bit,<span lang="ZH-CN">共占一个字节</span>,<span lang="ZH-CN">其值当前固定为</span>0x11<span lang="ZH-CN">。</span>CODE<span lang="ZH-CN">字段占用</span>1<span lang="ZH-CN">个字节</span>,<span lang="ZH-CN">其值标识</span>PPoE<span lang="ZH-CN">的报文类型 （</span>ADI<span lang="ZH-CN">－</span></span><span style="FONT-SIZE: 9pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">0x09</span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"> PADO<span lang="ZH-CN">－</span></span><span style="FONT-SIZE: 9pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">0x07</span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"> PADR<span lang="ZH-CN">－</span></span><span style="FONT-SIZE: 9pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">0x19</span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"> PADS<span lang="ZH-CN">－</span></span><span style="FONT-SIZE: 9pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">0x65</span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"> PADT<span lang="ZH-CN">－</span></span><span style="FONT-SIZE: 9pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">0xa7</span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">,PPP<span lang="ZH-CN">会话阶段时此字段为</span></span><span style="FONT-SIZE: 9pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">0x0</span><span lang="ZH-CN" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">）。</span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">SESSION_ID<span lang="ZH-CN">字段占用</span>2<span lang="ZH-CN">个字节</span>,<span lang="ZH-CN">在</span>NAS<span lang="ZH-CN">向</span>Host<span lang="ZH-CN">发送</span>ADS<span lang="ZH-CN">报文时会分配一个可用的</span>SESSION_ID<span lang="ZH-CN">填入此字段告诉</span>Host<span lang="ZH-CN">。</span>LENGTH<span lang="ZH-CN">字段占用</span>2<span lang="ZH-CN">个字节</span>,<span lang="ZH-CN">标识后边</span>payload<span lang="ZH-CN">的长度 （</span></span><b><span style="FONT-FAMILY: Arial; mso-bidi-font-size: 9.0pt;">Note</span></b><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">:<span lang="ZH-CN">不含前面</span>ETHERNET<span lang="ZH-CN">头和</span>PPPoE<span lang="ZH-CN">头以及自身的长度）。</span><p></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"><p>&nbsp;</p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 21pt; TEXT-INDENT: -21pt; tab-stops: list 21.0pt; mso-list: l0 level1 lfo1;"><span style="FONT-FAMILY: Wingdings; mso-fareast-font-family: Wingdings; mso-bidi-font-family: Wingdings;"><span style="mso-list: Ignore;">n<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><span style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto;"><font face="Times New Roman">PPP</font></span><span lang="ZH-CN" style="BACKGROUND: #d9d9d9; FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-shading: white; mso-pattern: gray-15 auto;">封装格式</span><span style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto;"><p></p></span></p><pre><span style="FONT-SIZE: 9pt;"><font face="宋体">+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<p></p></font></span></pre><pre style="tab-stops: 45.8pt 91.6pt 123.75pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;"><span style="FONT-SIZE: 9pt;"><font face="宋体">| PROTOCOL | <span style="mso-tab-count: 2;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>INFORMATION (&lt;=1500) <span style="mso-spacerun: yes;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span>|<p></p></font></span></pre><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<p></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">PROTOCOL</span><span style="FONT-SIZE: 9pt; COLOR: black;"><font face="Times New Roman">
                        </font></span><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">= LCP<span lang="ZH-CN">报文</span>(0xc021)<span lang="ZH-CN">、</span>CHAP<span lang="ZH-CN">报文</span>(0xc223)<span lang="ZH-CN">、</span>PAP<span lang="ZH-CN">报文</span>(0xc023)<span lang="ZH-CN">、</span>IPCP<span lang="ZH-CN">报文</span>(0x8021)<span lang="ZH-CN">、</span>IPv4(0x0021)<span lang="ZH-CN">。</span><p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span style="FONT-SIZE: 9pt; FONT-FAMILY: Helvetica; mso-font-kerning: 0pt;"><p>&nbsp;</p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 21pt; TEXT-INDENT: -21pt; tab-stops: list 21.0pt; mso-list: l0 level1 lfo1;"><span style="FONT-FAMILY: Wingdings; mso-fareast-font-family: Wingdings; mso-bidi-font-family: Wingdings;"><span style="mso-list: Ignore;">n<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><span lang="ZH-CN" style="BACKGROUND: #d9d9d9; FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-shading: white; mso-pattern: gray-15 auto;">有</span><span style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto;"><font face="Times New Roman">4</font></span><span lang="ZH-CN" style="BACKGROUND: #d9d9d9; FONT-FAMILY: 宋体; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-shading: white; mso-pattern: gray-15 auto;">种类型的以太网封装</span><span style="BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto;"><p></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: -21pt; tab-stops: list 42.0pt; mso-list: l0 level2 lfo1;"><span style="COLOR: black; mso-fareast-font-family: &quot;Times New Roman&quot;;"><span style="mso-list: Ignore;"><font face="Times New Roman">1.<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font></span></span><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">Ethernet </span><font face="Times New Roman"><span style="COLOR: black;">II</span><span style="COLOR: black;"><p></p></span></font></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: -21pt; tab-stops: list 42.0pt; mso-list: l0 level2 lfo1;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"><span style="mso-list: Ignore;">2.<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">Novell-Specific Framing (raw 802.3)<p></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: -21pt; tab-stops: list 42.0pt; mso-list: l0 level2 lfo1;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"><span style="mso-list: Ignore;">3.<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">Ethernet 802.3/802.2 without SNAP<p></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 42pt; TEXT-INDENT: -21pt; tab-stops: list 42.0pt; mso-list: l0 level2 lfo1;"><span style="COLOR: black; mso-fareast-font-family: &quot;Times New Roman&quot;;"><span style="mso-list: Ignore;"><font face="Times New Roman">4.<span style="FONT: 7pt &quot;Times New Roman&quot;;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></font></span></span><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">Ethernet 802.3/802.2 with SNAP(<b style="mso-bidi-font-weight: normal;">S</b>ub<b style="mso-bidi-font-weight: normal;"> N</b>etwork <b style="mso-bidi-font-weight: normal;">A</b>ccess <b style="mso-bidi-font-weight: normal;">P</b>rotocol)</span><span style="COLOR: black;"><p></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 21pt;"><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"><p>&nbsp;</p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;"><a href="http://www.cisco.com/warp/public/cc/techno/media/lan/gig/tech/gigbt_tc.htm"></a><u><font color="#0000ff"></font></u><p></p></span></p>