112 lines
7.9 KiB
HTML
112 lines
7.9 KiB
HTML
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<?xml version="1.0" encoding="utf-8"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="dc.language" scheme="rfc1766" content="en-us" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<meta name="dc.date" scheme="iso8601" content="2005-09-06" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
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<title>High-performance routing</title>
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<link rel="stylesheet" type="text/css" href="ibmidwb.css" />
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<link rel="stylesheet" type="text/css" href="ic.css" />
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</head>
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<body>
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<a id="Top_Of_Page" name="Top_Of_Page"></a><!-- Java sync-link -->
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<script language = "Javascript" src = "../rzahg/synch.js" type="text/javascript"></script>
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<a name="rzajthpr-ref"></a>
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<h3 id="rzajthpr-ref">High-performance routing</h3>
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<p>High-Performance Routing (HPR) is the evolution of Advanced Peer-to-Peer
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Networking® (APPN). HPR enhances APPN data routing performance and reliability,
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especially when using higher-speed lower-error links.</p>
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<p>To support high-speed communications facilities, certain changes to the
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APPN architecture are required. These are necessary to allow switching in
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intermediate nodes to be done at a lower layer and to enable faster switching
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than in base APPN support. HPR changes the existing APPN intermediate session
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routing by using automatic network routing (ANR), which maximizes the storage
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and processing requirement in intermediate nodes. Each outbound packet has
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a predetermined path through the network so that intermediate routing nodes
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need not remember anything about HPR sessions that flow through them. Intermediate
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routing nodes in HPR simply route data that is based on information that is
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contained within the packet itself.</p>
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<p><img src="delta.gif" alt="Start of change" /><span class="bold">Enterprise Extender (SNA over IP networks using
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HPR)</span><img src="deltaend.gif" alt="End of change" /></p>
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<p><img src="delta.gif" alt="Start of change" />Enterprise Extender is a networking architecture that allows
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Systems Network Architecture (SNA) applications to run over Internet Protocol
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(IP) networks using High Performance Routing (HPR). This is the preferred
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way to run SNA applications over IP networks with communications input/output
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adapters (IOAs), such as Gigabit Ethernet, since these IOAs do not require
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an input/output processor (IOP) and, therefore, do not natively support SNA. IBM® recommends
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that Enterprise Extender be used in place of AnyNet®.<img src="deltaend.gif" alt="End of change" /></p>
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<p><img src="delta.gif" alt="Start of change" />Enterprise Extender utilizes the following HPR option sets:
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1401, 1402, 2006, and 2009. These option sets, as well as 1400, are described
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below.<img src="deltaend.gif" alt="End of change" /></p>
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<p><img src="delta.gif" alt="Start of change" />The HPR function can operate under a base architecture, or can
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operate under the base architecture plus options. There are performance capabilities
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available under the <span class="italic">Tower RTP</span> (Rapid Transport Protocol)
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option not available with the base. See the following for a more thorough
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explanation of what architecture option is appropriate for you.</p>
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<ul>
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<li><span class="bold">HPR-base option</span> (option set 1400): Its primary function
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is to provide automatic network routing (ANR). Products that only use this
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function can participate as intermediate nodes in one or more Rapid Transport
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Protocol (RTP) connections. This type of implementation cannot be an endpoint
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of an RTP connection. An addition to the base option is HPR link-level error
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recovery. A system that supports high-speed links does not always require
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link-level error recovery. It is optional because when link-level error recovery
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is eliminated, faster communications might occur when using high-quality data
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transmission.</li>
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<li><span class="bold">RTP Tower option</span> (option set 1401): Implementations
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that support this option can act as an endpoint and are able to transport
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logical-unit to logical-unit session (LU-LU-session) session traffic across
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HPR networks by using Rapid Transport Protocol (RTP) connections. An RTP connection
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can only be made between two systems that support RTP. That is, there can
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only be a mix of systems in a given RTP connection's path through the network
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(systems that only support the HPR base option and systems that support the
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HPR tower option). However, there is the stipulation that <span class="italic">at least</span> the two end points in the path support the HPR tower option.
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Otherwise, APPN is used.
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<a name="wq2"></a>
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<div class="notetitle" id="wq2">Note:</div>
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<div class="notebody">An implementation that has the RTP
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Tower option also supports the base option. These systems can run as intermediate
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systems in the path.</div></li>
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<li><img src="delta.gif" alt="Start of change" /><span class="bold">Control Flows over RTP Tower option</span> (option
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set 1402): This option causes control-point to control-point sessions (CP-CP
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sessions) and route setup messages to flow over special RTP connections. CP-CP
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sessions are established between adjacent node pairs and are used to broadcast
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topology flows to the entire network so that every node has the topology for
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the entire network stored in its topology database. <span class="italic">Route
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setup messages</span> are request and reply messages that are used to obtain
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information about a route over which an RTP connection will be established.
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The route setup request is sent by the origin node to the destination node
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over the exact route that is to be used. It stops at each intermediate node
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along the way to gather information associated with the forward path. The
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route setup reply is returned by the destination node after receiving the
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route setup request. The reply follows the same path as the request (in the
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reverse direction) and stops at each intermediate node along the way to gather
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information about the reverse path. When the origin node receives the reply
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it uses the information to establish a new RTP connection or reroute an existing
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one.<img src="deltaend.gif" alt="End of change" /></li>
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<li><img src="delta.gif" alt="Start of change" /><span class="bold">Logical Data Link Control (LDLC) Support option</span> (option set 2006): LDLC is a Logical Link Control (LLC) type defined
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to be used with HPR networks in conjunction with the Control Flows over RTP
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Tower option (option set 1402) over reliable links that do not require link-level
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error recovery. LDLC is only used for Enterprise Extender links.<img src="deltaend.gif" alt="End of change" /></li>
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<li><img src="delta.gif" alt="Start of change" /><span class="bold">Native IP Data Link Control (DLC) option</span> (option
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set 2009): Native IP is a DLC option used with option sets 1400, 1401, 1402,
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and 2006 to allow you to take advantage of APPN/HPR functions such as class
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of service (COS) and adaptive rate based flow/congestion control in the IP
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environment. This option set contains the support for Enterprise Extender
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links.<img src="deltaend.gif" alt="End of change" /></li></ul><img src="deltaend.gif" alt="End of change" />
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<a id="Bot_Of_Page" name="Bot_Of_Page"></a>
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</body>
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</html>
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