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<concept id="GUID-1277D793-4A0A-50A7-9414-AEE93E906E80" xml:lang="en"><title>Sockets

Server Architecture</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>This section describes the architecture of the Sockets Server and the framework

that implements sockets in Symbian platform. </p>

<p>The sockets are similar in concept to Berkeley Software Distribution (BSD)

sockets from the University of California at Berkeley. The sockets provide

a generic interface to network level communications protocols for common operations

in network computing. Common operations are: </p>

<ul>

<li id="GUID-3CFD5267-2254-5816-9443-E4256579E01D"><p>establish a connection </p> </li>

<li id="GUID-C1061692-C402-5EB1-91E9-EEB3BD3410CE"><p>send data </p> </li>

<li id="GUID-445FF07E-FC13-589A-B375-DED728F88E06"><p>receive data </p> </li>

<li id="GUID-BBC3CE6E-01FA-52E6-BE5E-A53A2E5423AC"><p>configure network protocols </p> </li>

</ul>

<p>The Sockets Client API provides access to other network facilities. Examples

of network facilities are: </p>

<ul>

<li id="GUID-E77E0241-2D8F-531B-93D3-78BD910BCEB4"><p>hostname resolution </p> </li>

<li id="GUID-EB93A7E8-33BC-5A82-9CD7-8AB7065CDB1B"><p>service resolution </p> </li>

<li id="GUID-439CE845-2A89-5886-81DD-9F3DD0537346"><p>information about protocols </p> </li>

<li id="GUID-2AE98676-FEAC-5B49-BB39-1BD635F24FDF"><p>byte manipulation utilities </p> </li>

</ul>

<section id="GUID-986AB642-22DE-422C-965A-F70CC7A79779"><title>Required Background</title> <p>A

working knowledge of socket based communications is recommended in order to

understand how Symbian platform implements sockets. </p> <p>A knowledge of

the selected protocol is also required if the application is going to set

or get values specific to the protocol. For example, the knowledge is required

to understand the data returned from <xref href="GUID-EF29C1D7-B1E5-370F-AE37-66231A6BE449.dita#GUID-EF29C1D7-B1E5-370F-AE37-66231A6BE449/GUID-1B597C97-2AEB-32D1-B225-5C1E24F6470F"><apiname>RSocketServ::GetProtocolInfo()</apiname></xref>.

The knowledge is also required if the application sets <xref href="GUID-9A20701F-5744-5F5F-BB0C-AB58EFB7D087.dita">Quality

of Service</xref> (QoS) values. </p> </section>

<section id="GUID-EBF65B0F-AFAE-4DA4-8B9F-E0E816FB6B67"><title>Key Concepts/Terms</title> <p>The

Sockets Server starts when Symbian platform starts, and receives requests

for socket based communications. If a request is received for a particular

protocol, the Sockets Server loads the appropriate protocol modules to handle

that request. </p> </section>

<section id="GUID-7CE8ED89-2543-4E11-A9A4-9D2BC0B061B2"><title>Architectural

relationships</title> <p>The Sockets Server provides a generic client interface,

and a server to which particular protocol modules can be plugged in. A client

uses a particular protocol by supplying protocol-specific parameters to Sockets

API functions. </p> <fig id="GUID-253611E8-9893-5261-830F-28B888FFA15B">

<title>              Figure 1 - The Socket Server's position in the Communications

             Framework Architecture.            </title>

<image href="GUID-8E6FD3FD-64C8-51E0-AFE7-76DC5AB6A254_d0e110788_href.png" placement="inline"/>

</fig> <p>The TCP/IP API enables clients to use sockets for TCP/IP, including

UDP, TCP, ICMP, IPv4, IPv6, ARP, and DNS. </p> <p>The IrDA Sockets API enables

clients to use sockets for IrDA infra-red. </p> <p>The Bluetooth Sockets API

enables clients to use sockets for Bluetooth. </p> <p>The SMS PRT API provides

the GSM SMS Protocol stack and the WAP protocol stack over SMS. </p> </section>