diff options
| author | Sven Eisenhauer <sven@sven-eisenhauer.net> | 2023-11-10 15:11:48 +0100 |
|---|---|---|
| committer | Sven Eisenhauer <sven@sven-eisenhauer.net> | 2023-11-10 15:11:48 +0100 |
| commit | 33613a85afc4b1481367fbe92a17ee59c240250b (patch) | |
| tree | 670b842326116b376b505ec2263878912fca97e2 /Bachelor/CCNA4/en_CCNA4_v30/ch2/2_1_6/content.html | |
| download | Studium-master.tar.gz Studium-master.tar.bz2 | |
Diffstat (limited to 'Bachelor/CCNA4/en_CCNA4_v30/ch2/2_1_6/content.html')
| -rw-r--r-- | Bachelor/CCNA4/en_CCNA4_v30/ch2/2_1_6/content.html | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/Bachelor/CCNA4/en_CCNA4_v30/ch2/2_1_6/content.html b/Bachelor/CCNA4/en_CCNA4_v30/ch2/2_1_6/content.html new file mode 100644 index 0000000..b6c42c7 --- /dev/null +++ b/Bachelor/CCNA4/en_CCNA4_v30/ch2/2_1_6/content.html @@ -0,0 +1,147 @@ +<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">
+</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</font></b><font face="Arial" size="2" color="#FFFFFF"><b>.1</b></font></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 Overview</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">
+ 2.1.6</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">WAN link options</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">
+ Figure <img border="0" src="../../images/1.gif" align="absmiddle" width="12" height="12">
+ provides an overview of WAN link options.
+ <p>Circuit switching establishes a dedicated physical connection for voice
+ or data between a sender and receiver. Before communication can start, it
+ is necessary to establish the connection by setting the switches. This
+ is done by the telephone system, using the dialed number. ISDN is used
+ on digital lines as well as on voice-grade lines. If the local loop is
+ not directly connected to the telephone system, a digital subscriber
+ line (DSL) may be available.</p>
+ <p>To avoid the delays associated with setting up a connection,
+ telephone service providers also offer permanent circuits. These
+ dedicated or leased lines offer higher bandwidth than is available
+ with a switched circuit. Examples of circuit-switched connections
+ include:</p>
+ <ul>
+ <li>Plain Old Telephone System (POTS)</li>
+ <li>ISDN Basic Rate Interface (BRI)</li>
+ <li>ISDN Primary Rate Interface (PRI)</li>
+ </ul>
+ <p>Many WAN users do not make efficient use of the fixed bandwidth
+ that is available with dedicated, switched, or permanent circuits, because the data flow
+ fluctuates. Communications providers have data networks available to
+ more appropriately service these users. In these networks, the data is transmitted in labeled
+ cells, frames, or packets through a packet-switched network. Because
+ the internal links between the switches are shared between many users,
+ the costs of packet switching are lower than those of circuit
+ switching. Delays (latency) and variability of delay (jitter) are
+ greater in packet-switched than in circuit-switched networks. This is
+ because the links are shared and packets must be entirely received at
+ one switch before moving to the next. Despite the latency and jitter
+ inherent in shared networks, modern technology allows satisfactory
+ transport of voice and even video communications on these networks.</p>
+ <p>Packet-switched networks may establish routes through the switches
+ for particular end-to-end connections. Routes established when the
+ switches are started are PVCs. Routes established on demand are SVCs. If the routing is not
+ pre-established and is worked out by each switch for each packet, the
+ network is called connectionless.</p>
+ <p>To connect to a packet-switched network, a subscriber needs a local
+ loop to the nearest location where the provider makes the service
+ available. This is called the point-of-presence (POP) of the service.
+ Normally this will be a dedicated leased line. This line will be much
+ shorter than a leased line directly connected to
+ the subscriber locations, and often carries several VCs.
+ <img border="0" src="../../images/2.gif" align="absmiddle" width="12" height="12"> Since it
+ is likely that not all the VCs will require maximum demand
+ simultaneously, the capacity of the leased line can be smaller than
+ the sum of the individual VCs. Examples of packet or cell switched
+ connections include:</p>
+ <ul>
+ <li>Frame Relay</li>
+ <li>X.25</li>
+ <li>ATM</li>
+ </ul>
+ <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">
+ <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>WAN<p>
+ <a target="_blank" href="http://www.cisco.com/en/US/tech/tk713/tech_topology_and_network_serv_and_protocol_suite_home.html">
+ http://www.cisco.com/en/US/tech/ tk713/
+ tech_topology_and_ network_serv_and_
+ protocol_suite_ home.html</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>
\ No newline at end of file |