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<concept id="GUID-C2CF49A8-E1AC-565B-8C7F-28C89D59600F" xml:lang="en"><title>What

is the Packet Context ?</title><shortdesc>The packet context encapsulate the functions related to the context

of a packet switched network connection. The context of a connection relates

to factors such as the protocol type, the access point to the network and

the DNS and authentication parameters. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>The context is associated with a particular <xref href="GUID-6C557DE7-160B-5B90-B017-AD8762F6B8A9.dita">packet

service</xref>. </p>

<p>Contexts for each network type are supported by different member classes

in the <xref href="GUID-1CD9122E-B077-39FD-8CAE-45A6AF8F345F.dita"><apiname>RPacketContext</apiname></xref>: </p>

<ul>

<li id="GUID-C383F0B1-0736-57B4-9CC9-EE837031DA85"><p> <xref href="GUID-1CD9122E-B077-39FD-8CAE-45A6AF8F345F.dita"><apiname>RPacketContext::TContextConfigGPRS</apiname></xref>, </p> </li>

<li id="GUID-06926496-F4CA-5A5E-9B64-598BB5E8367E"><p> <xref href="GUID-1CD9122E-B077-39FD-8CAE-45A6AF8F345F.dita"><apiname>RPacketContext::TContextConfigR99_R4</apiname></xref> (from

v7.0s onwards) </p> </li>

<li id="GUID-F939554B-77DA-55C0-9271-4CB40D73BD76"><p> <xref href="GUID-1CD9122E-B077-39FD-8CAE-45A6AF8F345F.dita"><apiname>RPacketContext::TContextConfigCDMA</apiname></xref>. </p> </li>

</ul>

<p>Symbian platform provides the authentication parameters to

support CHAP and PAP authentication methods. Previously only PAP authentication

was supported. The CHAP authentication is more secure than the PAP authentication.

The additional functions are: </p>

<ul>

<li id="GUID-520F5D86-B5A3-5588-A981-74130C3D748A"><p>Point to Point Protocol

(PPP) authentication parameters, that is the CHAP and PAP parameters to support

authentication access with the Gateway GPRS Support Node (GGSN) and Authentication

Authorization and Accounting (AAA) systems. It is up to the client to decide

which mode of authentication to use. </p> </li>

<li id="GUID-C2AC0BA5-3670-535A-8EB3-9266AF10311F"><p>CHAP authentication

can get the Domain Name System (DNS) server name parameters like primary DNS

and secondary DNS. The DNS server name is required in the authentication process.

AAA may deliver DNS IP addresses to the network, so the Packet Data API supports

delivering these addresses to the client. For more information see GSM Standards <xref href="http://webapp.etsi.org/exchangefolder/ts_124008v032000p.pdf" scope="external">09.61</xref> and <xref href="http://www.3gpp.org/ftp/Specs/archive/24_series/24.008/" scope="external">24.008</xref>. </p> </li>

<li id="GUID-88370C4C-3444-557E-B4AE-EA51A5A97ABB"><p>The authentication can

be used for both the primary and secondary contexts. A primary context configuration

is set without reference to another context. Secondary contexts are created

from an existing context that can be a primary or secondary context. </p> </li>

</ul>

<p>This API is implemented by <xref href="GUID-1CD9122E-B077-39FD-8CAE-45A6AF8F345F.dita"><apiname>RPacketContext</apiname></xref>. </p>

<section id="GUID-39AAFDFC-501D-571C-9247-CDC3F5ABBF5E"><title>Packet context

functions</title> <p>The <xref href="GUID-1CD9122E-B077-39FD-8CAE-45A6AF8F345F.dita"><apiname>RPacketContext</apiname></xref> API

functions enable the clients to do the following: </p> <ul>

<li id="GUID-269C64FE-7EFB-5179-AFBB-93FB79EA83DD"><p>Obtain a secondary packet

context from an existing packet. The second packet uses the same context information.

The Quality of Service information is not used. </p> </li>

<li id="GUID-5B469031-4C8C-57E1-A347-FDE932F6233A"><p>Configure the Quality

of Service specifications of Release99 and Release4 in the packet context. </p> </li>

<li id="GUID-F4E3E8C2-87D0-5587-A776-ACA5A4EDF35D"><p>Modify the negotiated

QoS of an active context. </p> </li>

<li id="GUID-C4212719-F29A-5143-8658-4849C175AE3F"><p>Add, remove and change

the packet filters in the Traffic Flow template of a context. The clients

can also create and delete the Traffic Flow templates. </p> </li>

<li id="GUID-B07C16B0-52C8-5B14-A0FA-7B3E03BD9BD2"><p>Discover context information

for a network interface (NIF) level. </p> </li>

<li id="GUID-21A4445A-94D7-5EF1-802A-022BD493614E"><p>Retrieve the current

packet network release mode to receive roaming notification between the release

modes. </p> </li>

</ul> </section>

<section id="GUID-894B301D-A3B6-494B-84A4-1D5508E63F4D"><title>See also</title> <p> <xref href="GUID-5491D859-C348-5C39-AAE0-783A3A4B69B3.dita">Architecture</xref> </p> </section>

</conbody></concept>