[求助]什么是路由型城域网和交换型城域网？

狐一郎

<p>&nbsp;今天看一篇资料文章的时候提到：</p><div class="O" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: tahoma;"><span style="FONT-SIZE: 110%; COLOR: #6f89f7; FONT-FAMILY: wingdings; mso-special-format: bullet; mso-bullet-image: 'c:
mso-color-index:6;;"></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>路由型城域网（如：长沙） </b></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: tahoma;"><span style="FONT-SIZE: 60%; FONT-FAMILY: wingdings; mso-special-format: bullet;"><font size="1">n</font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>出口和核心层采用路由器组网 </b></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: tahoma;"><span style="FONT-SIZE: 60%; FONT-FAMILY: wingdings; mso-special-format: bullet;"><font size="1">n</font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>三层交换机兼作二层汇接、三层接入和三层汇接 </b></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: tahoma;"><span style="FONT-SIZE: 60%; FONT-FAMILY: wingdings; mso-special-format: bullet;"><font size="1">n</font></span></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>BRAS</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>旁挂三层交换机，作</b></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>PPoE</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>接入 </b></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: tahoma;"><span style="FONT-SIZE: 60%; FONT-FAMILY: wingdings; mso-special-format: bullet;"><font size="1">n</font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>部分专设</b></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>MPLS PE</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>，旁挂三层交换机或旁挂</b></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>GSR </b></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><strong></strong></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><div class="O" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>交换型城域网（省内其它本地网） </b></span></div><span style="FONT-FAMILY: tahoma;"><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-SIZE: 60%; FONT-FAMILY: wingdings; mso-special-format: bullet;"><font size="1">n</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>无出口路由器，城域网作为</b></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>ChinaNet</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>的本地延伸网络</b></span></div></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>无出口路由器，城域网作为</b></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>ChinaNet</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>的本地延伸网络</b></span><font face="宋体">
                        </font><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>三层交换机组成城域网网络核心 </b></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: tahoma;"><span style="FONT-SIZE: 60%; FONT-FAMILY: wingdings; mso-special-format: bullet;"><font size="1">n</font></span></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>三层交换机兼作二层汇接、三层接入和三层汇接 </b></span></div><span style="FONT-FAMILY: tahoma;"><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-SIZE: 60%; FONT-FAMILY: wingdings; mso-special-format: bullet;"><font size="1">n</font></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>BRAS</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>旁挂三层交换机，作</b></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>PPoE</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>接入 </b></span></div></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>BRAS</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>旁挂三层交换机，作</b></span><span lang="EN-US" style="FONT-FAMILY: tahoma; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman'; mso-fareast-language: zh-cn;"><b>PPoE</b></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><b>接入 </b></span><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><strong></strong></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><strong></strong></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><strong></strong></span></div><div class="O1" style="mso-line-spacing: '100 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: tahoma; mso-fareast-font-family: 宋体; mso-hansi-font-family: 'times new roman';"><strong><font color="#ff0000">两者有什么区别和联系?</font></strong></span></div></span></div>