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<td bgcolor="#336666"><b><font face="Arial" size="2" color="#FFFFFF">5</font></b><font face="Arial" size="2" color="#FFFFFF"><b>.1</b></font></td>
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<td bgcolor="#336666" width="100%"><b style="mso-bidi-font-weight:normal"><span style="font-family:Arial;mso-bidi-font-family:"Times New Roman""><o:p>
<font size="2" color="#FFFFFF">Frame Relay Concepts</font>
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<td bgcolor="#669999" height="25"><b>
<font face="Arial" size="2" color="#FFFFFF">5.1.7</font></b></td>
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<td bgcolor="#669999" height="25" width="100%"><strong>
<font face="Arial" size="2" color="#FFFFFF">Stages of Inverse ARP and LMI
operation</font></strong></td>
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<font FACE="Arial" SIZE="2">
LMI status messages combined with Inverse ARP messages allow a router
to associate network layer and data link layer addresses.</font><p>
<font FACE="Arial" SIZE="2">
When a router that is connected to a Frame Relay network is started, it sends
an LMI status inquiry message to the network. The network replies with
an LMI status message containing details of every VC configured on the
access link.
<img border="0" src="../../images/1.gif" align="absmiddle" width="12" height="12"></font></p>
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Periodically the router repeats the status inquiry, but subsequent
responses include only status changes. After a set number of these
abbreviated responses, the network will send a full status message.</font></p>
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<font FACE="Arial" SIZE="2">
If the router needs to map the VCs to network layer addresses, it will
send an Inverse ARP message on each VC. The Inverse ARP message
includes the network layer address of the router, so the remote DTE,
or router, can also perform the mapping. The Inverse ARP reply allows
the router to make the necessary mapping entries in its address to
DLCI map table. If several network layer protocols are supported on
the link, Inverse ARP messages will be sent for each.
<img border="0" src="../../images/2.gif" align="absmiddle" width="12" height="12"></font></p>
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