diff -r 89d6a7a84779 -r 25a17d01db0c Symbian3/PDK/Source/GUID-5580195F-3DE7-55FA-B2C1-91A950A39C6E.dita
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/PDK/Source/GUID-5580195F-3DE7-55FA-B2C1-91A950A39C6E.dita	Fri Jan 22 18:26:19 2010 +0000
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+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
+<!-- This component and the accompanying materials are made available under the terms of the License 
+"Eclipse Public License v1.0" which accompanies this distribution, 
+and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
+<!-- Initial Contributors:
+    Nokia Corporation - initial contribution.
+Contributors: 
+-->
+<!DOCTYPE concept
+  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="GUID-5580195F-3DE7-55FA-B2C1-91A950A39C6E" xml:lang="en"><title>Nodes
+in Symbian Platform</title><shortdesc>This topic describes the basic concept of a <i>Node</i> in Symbian
+platform. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
+
+<p>The Communications Framework is modular and can adapt to changes in the
+networks that are available. The Communications Framework can also adapt to
+changes in technology. The modular design is described as a <i>Distributed
+Object Model</i>. Nodes are the components of a Distributed Object Model. </p>
+<p>A Distributed Object Model describes a system of entities or <i>Nodes</i> that
+can exist in different run contexts. The Nodes can exchange asynchronous messages.
+In Symbian platform, the concept of different run contexts refers to separate
+threads and separate processes. The scope of a Node is limited to a device.
+A Node cannot exist on a separate device. </p>
+<p>Symbian platform provides the Distributed Object Model framework that the
+Communications Architecture uses. The Distributed Object Model framework is
+a general purpose tool that other software entities can also use. </p>
+<p>A Node is an object that has an interface and an address. A Node uses messages
+to communicate with other Nodes. Some types of Node can use direct function
+calls to communicate if speed is important. Symbian platform defines the interface
+to a Node as the sequence of messages that the Node knows and to which the
+Node responds. </p>
+<p>A Node is an instance of a class derived from <xref href="GUID-3462501E-FDE1-3F3C-B26D-7FF3C826311F.dita"><apiname>ANodeBase</apiname></xref>. </p>
+<p>A parent Node is responsible for the destruction of its child Nodes. A
+parent Node can pass a reference to a child Node to other Nodes and implements
+the concept of containment. </p>
+<p>Nodes have <i>Roles</i>. A Role : </p>
+<ul>
+<li id="GUID-FCAA95EC-73CE-55D6-958F-4489069915D9"><p>identifies a service
+that the Node provides </p> </li>
+<li id="GUID-D9A10365-54BC-5F28-A081-FBB9963FCA38"><p>describes the series
+of messages that a Node sends and receives as part of a service </p> </li>
+</ul>
+<p>A Node can have more than one role. Examples of roles are as follows: </p>
+<ul>
+<li id="GUID-76207994-4326-5CB1-BE14-F20037A9B0BE"><p>a Node can accept requests
+to connect to another Node. </p> </li>
+<li id="GUID-3F4B59F6-12DD-5381-ACE9-DD021F41BF66"><p>a Node can own other
+Nodes. This is the concept of the <i>parent</i> Node. </p> </li>
+<li id="GUID-1B92A012-72B4-5DAC-9F15-D7FB802E2625"><p>A Node can be owned
+by another Node. This is the concept of the <i>child</i> Node. </p> </li>
+</ul>
+</conbody></concept>
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