⭐ 欢迎来到虫虫下载站！ | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站
📤 上传资源

📄 001_31.htm

📁 通讯类的标准。对要开发SS7的朋友有很大帮助的。（通讯协议）
💻 HTM
字号:
🔍 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- saved from url=(0059)http://www.chinagk.org/technology/IPTech/001/css/001_31.htm -->
<HTML><HEAD><TITLE>001_31</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<STYLE type=text/css>.pg {
	LEFT: 0px; WIDTH: 635px; POSITION: absolute; TOP: 0px; HEIGHT: 983px
}
BODY {
	FONT-SIZE: 13px; COLOR: #000000; FONT-FAMILY: ""; BACKGROUND-COLOR: #ffffff
}
A {
	TEXT-DECORATION: none
}
.ps0 {
	LEFT: 234px; WIDTH: 169px; POSITION: absolute; TOP: 321px
}
.ps1 {
	LEFT: 195px; WIDTH: 248px; POSITION: absolute; TOP: 457px
}
.ps2 {
	LEFT: 64px; WIDTH: 529px; POSITION: absolute; TOP: 484px
}
.ps3 {
	LEFT: 37px; WIDTH: 556px; POSITION: absolute; TOP: 505px
}
.ps4 {
	LEFT: 37px; WIDTH: 517px; POSITION: absolute; TOP: 525px
}
.ps5 {
	LEFT: 565px; WIDTH: 29px; POSITION: absolute; TOP: 527px
}
.ps6 {
	LEFT: 37px; WIDTH: 482px; POSITION: absolute; TOP: 546px
}
.ps7 {
	LEFT: 64px; WIDTH: 537px; POSITION: absolute; TOP: 567px
}
.ps8 {
	LEFT: 64px; WIDTH: 530px; POSITION: absolute; TOP: 587px
}
.ps9 {
	LEFT: 31px; WIDTH: 341px; POSITION: absolute; TOP: 608px
}
.ps10 {
	LEFT: 64px; WIDTH: 530px; POSITION: absolute; TOP: 629px
}
.ps11 {
	LEFT: 37px; WIDTH: 268px; POSITION: absolute; TOP: 649px
}
.ps12 {
	LEFT: 64px; WIDTH: 530px; POSITION: absolute; TOP: 670px
}
.ps13 {
	LEFT: 37px; WIDTH: 557px; POSITION: absolute; TOP: 691px
}
.ps14 {
	LEFT: 37px; WIDTH: 564px; POSITION: absolute; TOP: 711px
}
.ps15 {
	LEFT: 37px; WIDTH: 557px; POSITION: absolute; TOP: 732px
}
.ps16 {
	LEFT: 37px; WIDTH: 557px; POSITION: absolute; TOP: 753px
}
.ps17 {
	LEFT: 37px; WIDTH: 557px; POSITION: absolute; TOP: 773px
}
.ps18 {
	LEFT: 37px; WIDTH: 557px; POSITION: absolute; TOP: 794px
}
.ps19 {
	LEFT: 37px; WIDTH: 464px; POSITION: absolute; TOP: 815px
}
.ps20 {
	LEFT: 64px; WIDTH: 212px; POSITION: absolute; TOP: 835px
}
.ps21 {
	LEFT: 64px; WIDTH: 530px; POSITION: absolute; TOP: 856px
}
.ps22 {
	LEFT: 37px; WIDTH: 562px; POSITION: absolute; TOP: 878px
}
.ps23 {
	LEFT: 37px; WIDTH: 556px; POSITION: absolute; TOP: 897px
}
.ps24 {
	LEFT: 332px; WIDTH: 189px; POSITION: absolute; TOP: 54px
}
.ps25 {
	LEFT: 541px; WIDTH: 37px; POSITION: absolute; TOP: 31px
}
.ps26 {
	LEFT: 45px; WIDTH: 43px; POSITION: absolute; TOP: 64px
}
.ft0 {
	FONT-SIZE: 12px
}
.ft2 {
	FONT-SIZE: 13px; FONT-FAMILY: "Times New Roman",Times,serif
}
.ft3 {
	FONT-STYLE: italic; FONT-FAMILY: ""
}
.ft4 {
	FONT-WEIGHT: bold; FONT-SIZE: 37px; FONT-STYLE: italic; FONT-FAMILY: "Times New Roman",Times,serif
}
.ft5 {
	FONT-SIZE: 21px; COLOR: #000000; FONT-STYLE: italic; FONT-FAMILY: ""
}
.em0 {
	FONT-SIZE: 10px; FONT-FAMILY: "Times New Roman",Times,serif
}
.em1 {
	FONT-SIZE: 13px; FONT-FAMILY: "Times New Roman",Times,serif
}
.em2 {
	FONT-SIZE: 13px; FONT-FAMILY: ""
}
.em3 {
	FONT-SIZE: 13px; FONT-STYLE: italic; FONT-FAMILY: "Times New Roman",Times,serif
}
.im0 {
	LEFT: 35px; WIDTH: 561px; POSITION: absolute; TOP: 24px
}
.im1 {
	LEFT: 88px; WIDTH: 449px; POSITION: absolute; TOP: 103px
}
.im2 {
	LEFT: 90px; WIDTH: 449px; POSITION: absolute; TOP: 354px
}
</STYLE>

<META content="MSHTML 6.00.2600.0" name=GENERATOR></HEAD>
<BODY>
<DIV class=pg></DIV><!-- bitmap and vector images are written here -->
<DIV class=im0><IMG height=64 src="001_31.files/right.jpg" width=563 
border=0></DIV>
<DIV class=im1><IMG height=209 src="001_31.files/001_31_2.jpg" width=449 
border=0></DIV>
<DIV class=im2><IMG height=91 src="001_31.files/001_31_3.jpg" width=449 
border=0></DIV><!-- text starts here --><SPAN class=ps0><NOBR><SPAN 
class=ft0>图<SPAN class=em0>1-17 &nbsp;&nbsp;H.245</SPAN>端点容量集（<SPAN 
class=em0>3</SPAN>）</SPAN></NOBR></SPAN> <SPAN class=ps1><NOBR><SPAN 
class=ft0>图<SPAN class=em0>1-18 
&nbsp;&nbsp;H.245</SPAN>主从判定（通过端点类型标识）</SPAN></NOBR></SPAN> <SPAN 
class=ps2><NOBR>显然，<SPAN class=em1>H.245</SPAN>终端容量交换信息是一个复杂的实体，<SPAN 
class=em1>ASN.1</SPAN>语法的使用使得包的<SPAN class=em1>16</SPAN>进制标</NOBR></SPAN> <SPAN 
class=ps3><NOBR>记实际上不可能用裸眼译码。因特网监视器提供了不同选项以明确指示多路复用、像在容量</NOBR></SPAN> <SPAN 
class=ps4><NOBR>表中一样列出音频视频容量、介质流的延迟限制、会话的多点容量、端点的同步容量。</NOBR></SPAN> <SPAN 
class=ps5><NOBR><SPAN class=ft2>ACK</SPAN></NOBR></SPAN> <SPAN 
class=ps6><NOBR>消息只是证实各个端点已经收到<SPAN 
class=em1>Set</SPAN>消息，没有发生冲突。它们也携带主从判定。</NOBR></SPAN> <SPAN 
class=ps7><NOBR>一旦容量交换完成，主从关系确定以后，阶段<SPAN 
class=em1>B</SPAN>完成，我们可以开始为介质传输打开逻辑信道。</NOBR></SPAN> <SPAN 
class=ps8><NOBR>任何一方发送<SPAN class=em1>H.245 OpenLogicalChannel</SPAN>消息时，阶段<SPAN 
class=em1>C</SPAN>开始。<SPAN class=em1>H.245</SPAN>中的逻辑信道是单向</NOBR></SPAN> <SPAN 
class=ps9><NOBR>（半双工）的，双向通信必须在每个方向打开一条信道。</NOBR></SPAN> <SPAN 
class=ps10><NOBR>图<SPAN class=em1>1-19</SPAN>中时<SPAN 
class=em1>H.245</SPAN>消息包含的信息。它说明了数据类型和多路复用参数，如选择有<SPAN 
class=em1>60ms</SPAN>延</NOBR></SPAN> <SPAN class=ps11><NOBR>迟的<SPAN 
class=em1>G.728</SPAN>音频，以及<SPAN class=em1>UDP</SPAN>端口设置为<SPAN 
class=em1>5005</SPAN>。</NOBR></SPAN> <SPAN 
class=ps12><NOBR>利用事先交换得到的端点容量集的性质，可以同时建立一个或多个逻辑信道。希望每个端</NOBR></SPAN> <SPAN 
class=ps13><NOBR>点选定的属性，可以使带宽使用限定在事先向<SPAN class=em1>GK</SPAN>发送<SPAN 
class=em1>RAS ARQ</SPAN>的范围之内。否则，如呼叫流所</NOBR></SPAN> <SPAN 
class=ps14><NOBR>示，阶段<SPAN class=em1>D</SPAN>开始起作用，这时接收端点和<SPAN 
class=em1>GK</SPAN>作出带宽请求（<SPAN class=em1>Bandwidth Request</SPAN>，<SPAN 
class=em1>BCR</SPAN>）<SPAN class=em1>RAS</SPAN>交换。</NOBR></SPAN> <SPAN 
class=ps15><NOBR>如果<SPAN class=em1>GK</SPAN>可以允许该请求，那么将返回一条<SPAN 
class=em1>BCF<SPAN class=em2>，</SPAN></SPAN>不过造成带宽差别的逻辑信道需要关闭，再用</NOBR></SPAN> 
<SPAN class=ps16><NOBR>新的多路复用参数打开。如果不存在带宽差别，那么不需要激活阶段<SPAN 
class=em1>D</SPAN>。在<SPAN class=em1>OpenLogicalChannel</SPAN></NOBR></SPAN> 
<SPAN class=ps17><NOBR>消息交换以后，介质会流入这些消息选定的端口。阶段<SPAN 
class=em1>D</SPAN>呼叫服务还包括状态更新、特定的会议</NOBR></SPAN> <SPAN class=ps18><NOBR>从<SPAN 
class=em1>MC</SPAN>点对点会议扩展到多点、附加服务、多点级联和第三方重新路由。这些特性对于呼叫完成</NOBR></SPAN> <SPAN 
class=ps19><NOBR>前的通告是有用的，例如我们在拨入由<SPAN 
class=em1>PBX</SPAN>控制的区域时经常听到的那些通知。</NOBR></SPAN> <SPAN 
class=ps20><NOBR>最后我们进入<SPAN class=em1>H.323</SPAN>中的中间呼叫。</NOBR></SPAN> <SPAN 
class=ps21><NOBR>呼叫生命期内的呼叫终止是在阶段<SPAN class=em1>E</SPAN>处理的。任何一方可以发送一条<SPAN 
class=em1>H.245 CloseLogical</SPAN></NOBR></SPAN> <SPAN class=ps22><NOBR><SPAN 
class=ft2>Channel<SPAN 
class=em2>命令，关闭视频、音频和数据通道。这条命令之后是</SPAN>endSessionCommand<SPAN 
class=em2>命令。此后，</SPAN></SPAN></NOBR></SPAN> <SPAN 
class=ps23><NOBR>端点再不会发送任何<SPAN class=em1>H.245</SPAN>信令消息。接收方也会发送一条<SPAN 
class=em1>CloseLogicalChannel</SPAN>命令以关闭另</NOBR></SPAN> <SPAN 
class=ps24><NOBR><SPAN class=ft3>第<SPAN class=em3>1</SPAN>章<SPAN 
class=em3>IP</SPAN>语音和交互应用的协议</SPAN></NOBR></SPAN> <SPAN class=ps25><NOBR><SPAN 
class=ft4>31</SPAN></NOBR></SPAN> <SPAN class=ps26><NOBR><SPAN 
class=ft5>文档</SPAN></NOBR></SPAN> </BODY></HTML>

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -