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diff --git a/Bachelor/CCNA4/en_CCNA4_v30/ch2/2_2_2/content.html b/Bachelor/CCNA4/en_CCNA4_v30/ch2/2_2_2/content.html new file mode 100644 index 0000000..2aab77a --- /dev/null +++ b/Bachelor/CCNA4/en_CCNA4_v30/ch2/2_2_2/content.html @@ -0,0 +1,181 @@ +<html>
+
+<head>
+<meta http-equiv="Content-Language" content="en-us">
+<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
+
+
+
+<title>Content</title>
+<base target="_self">
+<style>
+<!--
+span.msoIns
+ {mso-style-name:"";
+ text-decoration:underline;
+ text-underline:single;
+ color:teal}
+-->
+</style>
+</head>
+
+<body background="../../images/bg.gif" topmargin="0" leftmargin="0" marginheight="0" marginwidth="0" onLoad="window.focus();" link="#808080" vlink="#808080" alink="#808080">
+
+<table border="0" cellpadding="0" cellspacing="0" width="100%">
+ <tr>
+ <td bgcolor="#336666" width="18" valign="top">
+ <img border="0" src="../../images/content_lines.gif" width="16" height="25">
+ <img border="0" src="../../images/transdot.gif" width="2" height="1"></td>
+ <td bgcolor="#336666"><b><font face="Arial" size="2" color="#FFFFFF">2.2</font></b></td>
+ <td bgcolor="#336666"><img border="0" src="../../images/transdot.gif" width="10" height="1"></td>
+ <td bgcolor="#336666" width="100%">
+ <strong><font face="Arial" size="2" color="#FFFFFF">WAN Technologies</font></strong></td>
+ <td width="9" bgcolor="#336666"> </td>
+ </tr>
+ <tr>
+ <td bgcolor="#669999" height="25" width="18"> </td>
+ <td bgcolor="#669999" height="25"><b>
+ <font face="Arial" size="2" color="#FFFFFF">2.2.2</font></b></td>
+ <td bgcolor="#669999"><img border="0" src="../../images/transdot.gif" width="10" height="1"></td>
+ <td bgcolor="#669999" height="25" width="100%"><b><font face="Arial" size="2" color="#FFFFFF">
+ <strong>ISDN</strong>
+ </font></b></td>
+ <td bgcolor="#669999" height="25" width="9"> </td>
+ </tr></table>
+
+<table border="0" cellpadding="0" cellspacing="0" width="95%" bordercolor="#111111">
+ <tr>
+ <td width="15"></td>
+ <td>
+
+ <font face="Arial" size="2">The internal connections, or trunks, of
+ the PSTN have changed from carrying analog frequency-division
+ multiplexed signals, to time-division multiplexed (TDM) digital
+ signals. An obvious next step
+ is to enable the local loop to carry digital signals that result in
+ higher capacity switched connections.
+ <p>Integrated Services Digital Network (ISDN) turns the local loop into a
+ TDM digital connection. The connection uses 64 kbps bearer channels
+ (B) for carrying voice or data and a signaling, delta channel (D) for
+ call set-up and other purposes.
+ <p>Basic Rate Interface (BRI) ISDN is intended for the home and small
+ enterprise and provides two 64 kbps B channels and a 16 kbps D
+ channel. For larger installations, Primary Rate Interface (PRI) ISDN
+ is available. PRI delivers twenty-three 64 kbps B channels and one 64
+ kbps D
+ channel in North America, for a total bit rate of up to 1.544 Mbps.
+ This includes some additional overhead for synchronization. In Europe,
+ Australia, and other parts of the world, ISDN PRI provides thirty B
+ channels and one D channel for a total bit rate of up to 2.048 Mbps,
+ including synchronization overhead.
+ <img border="0" src="../../images/1.gif" align="absmiddle" width="12" height="12"> In North
+ America PRI corresponds to a T1 connection. The rate of international
+ PRI corresponds to an E1 connection.<p>The BRI D channel is
+ underutilized, as it has only two B channels to control. Some
+ providers allow the D channel to carry data at low bit rates such as
+ X.25 connections at 9.6 kbps.<p>For small WANs, the BRI ISDN can provide an ideal connection
+ mechanism. BRI has a call setup time that is less than a second, and
+ its 64 kbps B channel provide greater capacity than an analog modem
+ link.
+ <img border="0" src="../../images/2.gif" align="absmiddle" width="12" height="12"> If greater capacity is required, a second
+ B channel can be
+ activated to provide a total of 128 kbps. Although inadequate for video, this
+ would permit several simultaneous voice conversations in addition to
+ data traffic.<p>Another common application of ISDN is to provide additional capacity
+ as needed on a leased line connection. The leased line is sized to
+ carry average traffic loads while ISDN is added during peak demand
+ periods. ISDN is also used as a backup in the case of a failure of the
+ leased line. ISDN tariffs are based on a per-B channel basis and are
+ similar to those of analog voice connections.<p>With PRI ISDN, multiple B channels can be connected between two end
+ points. This allows for video conferencing and high bandwidth data
+ connections with no latency or jitter. Multiple connections can become
+ very expensive over long distances.</p>
+
+ <TABLE bgcolor="#B0AFAF" width="95%" border="0" cellspacing="0" cellpadding="0">
+ <TR>
+ <TD valign="top">
+ <TABLE bgcolor="#669999" width="100%" cellspacing="0" cellpadding="0" border="0">
+ <TR>
+ <TD width="5">
+ <img border="0" src="../../images/lab_toplft.gif" width="116" height="23"></TD>
+ <TD><IMG alt="" height="1" width="3" src="../../images/s.gif"></TD><TD align="right" valign="top">
+ <IMG alt="" src="../../images/corner_ur_7.gif" width="7" height="7"></TD>
+ </TR>
+ </TABLE>
+
+ <TABLE bgcolor="#B0AFAF" width="100%" cellspacing="0" cellpadding="0" border="0">
+ <TR>
+ <TD>
+ <TABLE width="100%" cellpadding="2" cellspacing="0" border="0" bordercolor="#111111">
+ <TR>
+ <TD bgcolor="#ffffff" width="15"> </TD>
+ <TD bgcolor="#ffffff"><font FACE="Arial" SIZE="2" COLOR="#000000">
+ <p><font color="#808080">
+ <a href="javascript:void(0)" onClick="window.open('../../activities/ch02/activity_2_2_2.html','Interactivity','width=740,height=390,toolbar=0,resizable=yes,scrollbars=0,screenX=26,screenY=38,left=26,top=38');">
+ <img border="0" src="../../images/media_icon.gif" width="25" height="25"></a> <b>
+ <a onClick="window.open('../../activities/ch02/activity_2_2_2.html','Interactivity','width=740,height=390,toolbar=0,resizable=yes,scrollbars=0,screenX=26,screenY=38,left=26,top=38');" href="javascript:void(0)">Interactive Media Activity</a></b></font></p>
+ </font><font FACE="Arial" SIZE="2" COLOR="#808080">
+ <p>Checkbox: WAN Technologies ISDN Dialup</p>
+ <p>Upon completing this activity, the student
+ will be able to identify the characteristics associated with an
+ ISDN dialup circuit.</p>
+ </font><font FACE="Arial" SIZE="2" COLOR="#000000">
+ <p><IMG alt="" height="2" width="1" src="../../images/s.gif"></p></TD>
+ </TR>
+ </TABLE>
+ </TD>
+ </TR>
+ </TABLE>
+ </TD>
+ </TR>
+ </TABLE>
+
+
+
+ <TABLE bgcolor="#B0AFAF" width="95%" border="0" cellspacing="0" cellpadding="0">
+ <TR>
+ <TD valign="top">
+ <TABLE bgcolor="#669999" width="100%" cellspacing="0" cellpadding="0" border="0">
+ <TR>
+ <TD width="5">
+ <img border="0" src="../../images/lab_toplft.gif" width="116" height="23"></TD>
+ <TD><IMG alt="" height="1" width="3" src="../../images/s.gif"></TD><TD align="right" valign="top">
+ <IMG alt="" src="../../images/corner_ur_7.gif" width="7" height="7"></TD>
+ </TR>
+ </TABLE>
+
+ <TABLE bgcolor="#B0AFAF" width="100%" cellspacing="0" cellpadding="0" border="0">
+ <TR>
+ <TD>
+ <TABLE width="100%" cellpadding="2" cellspacing="0" border="0" bordercolor="#111111">
+ <TR>
+ <TD bgcolor="#ffffff" width="15"> </TD>
+ <TD bgcolor="#ffffff"><font FACE="Arial" SIZE="2" COLOR="#000000">
+ <p><font color="#808080">
+ <img border="0" src="../../images/links_icon.gif" width="25" height="25">
+ <b>Web Links</b></font></p>
+ </font><font FACE="Arial" SIZE="2" COLOR="#808080">
+
+ <p>Integrated Services Digital Network (ISDN)<p>
+ <a target="_blank" href="http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/isdn.htm">
+ http://www.cisco.com/univercd/cc/td/doc/ cisintwk/ito_doc/isdn.htm</a></font></p>
+
+ <p>
+ <IMG alt="" height="2" width="1" src="../../images/s.gif"></p>
+ </TD>
+ </TR>
+ </TABLE>
+ </TD>
+ </TR>
+ </TABLE>
+ </TD>
+ </TR>
+ </TABLE><p>
+
+ </font> </td>
+ </tr>
+ </table>
+
+</body>
+
+</html>
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