72 lines
5.0 KiB
HTML
72 lines
5.0 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8"?>
|
||
|
|
<!DOCTYPE html
|
||
|
|
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
|
|
<html lang="en-us" xml:lang="en-us">
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||
|
|
<meta name="security" content="public" />
|
||
|
|
<meta name="Robots" content="index,follow" />
|
||
|
|
<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))' />
|
||
|
|
<meta name="DC.Type" content="concept" />
|
||
|
|
<meta name="DC.Title" content="Setting priorities: How to handle the classes" />
|
||
|
|
<meta name="abstract" content="After traffic is classified, differentiated service also requires a per-hop behavior to define how to handle the traffic." />
|
||
|
|
<meta name="description" content="After traffic is classified, differentiated service also requires a per-hop behavior to define how to handle the traffic." />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rzak8diffserv.htm" />
|
||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Format" content="XHTML" />
|
||
|
|
<meta name="DC.Identifier" content="rzak8handle" />
|
||
|
|
<meta name="DC.Language" content="en-us" />
|
||
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
||
|
|
<!-- US Government Users Restricted Rights -->
|
||
|
|
<!-- Use, duplication or disclosure restricted by -->
|
||
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ic.css" />
|
||
|
|
<title>Setting priorities: How to handle the classes</title>
|
||
|
|
</head>
|
||
|
|
<body id="rzak8handle"><a name="rzak8handle"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">Setting priorities: How to handle the classes</h1>
|
||
|
|
<div><p>After traffic is classified, differentiated service also requires
|
||
|
|
a per-hop behavior to define how to handle the traffic.</p>
|
||
|
|
<p>The server uses bits in the IP header to identify an IP packet's level
|
||
|
|
of service. Routers and switches allocate their resources based on the per-hop
|
||
|
|
behavior information in the IP header's type of service octet field. The
|
||
|
|
type of service octet field was redefined in the Request for Comments (RFC)
|
||
|
|
1349 and OS/400<sup>®</sup> V5R1
|
||
|
|
operating system. A per-hop behavior is the forwarding behavior that a packet
|
||
|
|
receives at a network node. It is represented by a value known as a <em>codepoint</em>.
|
||
|
|
Packets can be marked either at the server or at other parts of the network,
|
||
|
|
such as a router. For a packet to retain the service requested, every network
|
||
|
|
node must be differentiated service (DiffServ)-aware. That is, the equipment
|
||
|
|
must be able to enforce per-hop behaviors. To enforce per-hop behavior treatment,
|
||
|
|
the network node must be able to use queue scheduling and outbound priority
|
||
|
|
management. See the <a href="rzak8conditioners.htm">Traffic conditioners</a> topic for
|
||
|
|
more information about what it means to be DiffServ-aware.</p>
|
||
|
|
<p>If your packet passes through a router or switch that is not DiffServ-aware,
|
||
|
|
it will lose its level of service at that router. The packet is still handled,
|
||
|
|
but it might experience unexpected delay. On your iSeries™ server, you can use the pre-defined
|
||
|
|
per-hop behavior codepoints or you can define your own codepoint. It is not
|
||
|
|
recommended that you create your own codepoints for use outside your private
|
||
|
|
network. If you do not know which codepoints to assign, review <a href="rzak8phb.htm">Use codepoints to assign per-hop behaviors</a> topic.</p>
|
||
|
|
<p>Unlike integrated service, differentiated service traffic does not require
|
||
|
|
a reservation or per-flow treatment. All traffic placed in the same class
|
||
|
|
is treated equally.</p>
|
||
|
|
<p>Differentiated service can also be used to throttle traffic leaving a server.
|
||
|
|
This means that your iSeries server really uses differentiated service
|
||
|
|
to limit performance. Limiting a less-critical application allows a mission-critical
|
||
|
|
application to exit your private network first. When you create a class of
|
||
|
|
service for this policy, you are asked to set various limits on your server.
|
||
|
|
The performance limits include token bucket size, peak rate limit, and average
|
||
|
|
rate limit. The help topics within the quality of service (QoS)
|
||
|
|
function of iSeries Navigator
|
||
|
|
gives you more specific information about these limits. </p>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzak8diffserv.htm" title="This is the first type of outbound bandwidth policy you can create on your server. Differentiated service divides your traffic into classes. To carry out a differentiated service policy, you need to determine how you want to classify your network traffic and how to handle the different classes.">Differentiated service</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|