13 <p>Plug-ins connect to the system using the EPOC Component Object Model (ECom). ECom is based on client/server architecture and provides services to instantiate, resolve, and destroy instances of plug-ins at run time. For more information, see the <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/guide/System-Libraries-subsystem-guide/ecom/EcomArchitecture/index.html" format="application/java-archive">ECom architecture</xref>.</p>

    13 <p>Plug-ins connect to the system using the EPOC Component Object Model

    14 <fig id="GUID-C5D783F2-8388-4097-8276-BAC6D5B17C2C"><title>ECom framework</title><image href="GUID-231E58F2-7935-462A-B048-51729D8245D4_d0e8421_href.png"/></fig>

    14 (ECom). ECom is based on client/server architecture and provides services

    15 <p>A hostile or malfunctioning plug-in may cause crashes or security leaks, even on otherwise well-tested applications. The <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/guide/platsecsdk/index.html" format="application/java-archive">platform security</xref> architecture protects the processes by verifying that the plug-in has equal or greater set of capabilities than the process in which it is loaded. For more information, see the <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/guide/System-Libraries-subsystem-guide/ecom/EcomArchitecture/EcomPlatSec.html" format="application/java-archive">ECom and the platform security capability model</xref>. </p>

    15 to instantiate, resolve, and destroy instances of plug-ins at run time. For

    16 <p>For examples, see <xref href="http://www.forum.nokia.com/main/resources/technologies/symbian/code_and_examples.html" scope="external">Symbian C++ code and examples</xref> on Forum Nokia.</p>

    16 more information, see the <xref href="GUID-30201A05-C6CE-5D34-9BDF-CDA4EE44878D.dita">ECom

    17 <section><title>Communication plug-ins</title>

    17 Architecture</xref>.</p>

    18 <p>It is possible to use plug-ins to implement additional functionality to serial, socket, and messaging frameworks. These plug-ins are especially important for security because they deal with communication.</p>

    18 <fig id="GUID-C5D783F2-8388-4097-8276-BAC6D5B17C2C"><title>ECom framework</title><image href="GUID-231E58F2-7935-462A-B048-51729D8245D4_d0e12619_href.png"/></fig>

    19 <p>A hostile or malfunctioning plug-in may cause crashes or security leaks,

    20 even on otherwise well-tested applications. The <xref href="GUID-4BFEDD79-9502-526A-BA7B-97550A6F0601.dita">platform

    21 security</xref> architecture protects the processes by verifying that the

    22 plug-in has equal or greater set of capabilities than the process in which

    23 it is loaded. For more information, see the <xref href="GUID-9E4D75C0-D797-5541-8E52-3C6D154CC74A.dita">ECom

    24 and the Platform Security Architecture</xref>. </p>

    25 <p>For examples, see <xref href="GUID-E59A469E-A2B5-5DF0-BA7E-C50D4A38CCAA.dita">Plug-in

    26 Framework (ECom) Examples</xref>.</p>

    27 <section id="GUID-2268BF28-467F-409F-B68C-5D361E8C5FF0"><title>Communication

    28 plug-ins</title>

    29 <p>It is possible to use plug-ins to implement additional functionality

    30 to serial, socket, and messaging frameworks. These plug-ins are especially

    31 important for security because they deal with communication.</p>

    20 <li><p>For serial communication there are serial protocol modules (CSY modules ), which are loaded by the Serial Comms Server. For more information on serial communication, see <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/guide/Serial-Communications-subsystem-guide/SerialCommsServerClientGuide/index.html" format="application/java-archive">Using Serial Communications Server Client-Side</xref>.</p></li>

    33 <li><p>For serial communication there are serial protocol modules

    21 <li><p>For socket-based communication there are protocol modules (PRT), which are loaded by the Socket Server. For more information on socket-based communication, see <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/guide/Communications-Infrastructure-subsystem-guide/esock/index.html" format="application/java-archive">Using Socket Server</xref>.</p></li>

    34 (CSY modules ), which are loaded by the Serial Comms Server. For more information

    22 <li><p>For messaging there are Message Type Modules (MTM), which include both client and server components. MTMs are a set of <codeph>dll</codeph>s rather than a single <codeph>dll</codeph>. For more information, see <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/guide/Messaging-subsystem-guide/MessagingGuide/MessagingGuide3/index.html" format="application/java-archive">Message Type Modules</xref>.</p></li>

    35 on serial communication, see <xref href="GUID-9B83CDD4-FC94-51A0-AC67-CD04BCAFEF08.dita">Serial

    36 Communications Server</xref>.</p></li>

    37 <li><p>For socket-based communication there are protocol modules

    38 (PRT), which are loaded by the Socket Server. For more information on socket-based

    39 communication, see <xref href="GUID-61E0CD76-A2E3-5066-84A8-146EECA8ADCD.dita">Socket

    40 Server</xref>.</p></li>

    41 <li><p>For messaging there are Message Type Modules (MTM), which

    42 include both client and server components. MTMs are a set of <codeph>dll</codeph>s

    43 rather than a single <codeph>dll</codeph>. For more information, see <xref href="GUID-8B843382-D27A-5E36-8F60-304903F3AA41.dita">Message Type Module</xref>.</p>

    44 </li>