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<concept id="GUID-5287A403-1094-5682-A443-A6C2A04A1F23" xml:lang="en"><title>Creating
and Managing an RTP session</title><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>This page describes how to create a new session with the socket server
and how to open the session and set some of the session parameters. It also
describes how to use an RTP <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>RSocket</apiname></xref> interface. </p>
<p>To communicate with RTP, open a session with the <xref href="GUID-61E0CD76-A2E3-5066-84A8-146EECA8ADCD.dita">socket
server</xref>. You can open several sessions at the same time. </p>
<p>An <xref href="GUID-2C5D53A3-0211-5C14-BD7F-E89EB27BAD2A.dita">active scheduler</xref> must
be created and started before you open an RTP session. </p>
<section><title>Opening a session</title> <p> <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>RRtpSession::OpenL()</apiname></xref> opens
an RTP session and starts it. The method has four overloads. RTCP is enabled
for the first three overloads and is disabled for the last overload. </p> <codeblock id="GUID-AFB0BF5E-DE8C-5AAE-B693-B3F6721B5321" xml:space="preserve">IMPORT_C void OpenL(RSocketServ &amp;aServer, TSockAddr &amp;aLocalAddr, TSockAddr &amp;aRemoteAddr, TInt aMaxRXSize, RConnection &amp;aConnection, TInt aPriority=EPriorityNormal, const TDesC8 &amp;aCNAME=KNullDesC8);</codeblock> <codeblock id="GUID-DEF6E5F9-BC04-5092-B444-08EB85268431" xml:space="preserve">IMPORT_C void OpenL(RSocketServ &amp;aServer, TSockAddr &amp;aLocalAddr, TSockAddr &amp;aRemoteAddr, TInt aMaxRXSize, TInt aPriority=EPriorityNormal, const TDesC8 &amp;aCNAME=KNullDesC8);</codeblock> <codeblock id="GUID-53661685-AA43-5EBB-B3A3-EC3EE143CC0E" xml:space="preserve">IMPORT_C void OpenL(RSocket &amp;aSocket, TInt aMaxRXSize, RSocket &amp;aRtcpSocket, TInt aPriority=EPriorityNormal, const TDesC8 &amp;aCNAME=KNullDesC8);</codeblock> <codeblock id="GUID-5283B661-0617-5656-B004-8A70B04E5DD9" xml:space="preserve">IMPORT_C void OpenL(RSocket &amp;aSocket, TInt aMaxRXSize, TInt aPriority=EPriorityNormal);</codeblock> </section>
<section> <title>Setting session parameters</title> <p>After
creating an RTP session, you need to set the following parameters before sending
and receiving RTP packets: </p> <ul>
<li id="GUID-E68D70C1-99D6-59E3-81F7-D022F0FEF545"><p>the bandwidth for the
RTP stream, by calling the <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>SetBandwidth()</apiname></xref> method </p> </li>
<li id="GUID-9D89740D-74C2-5CDC-846E-9E10EFAFEBBC"><p>the conversion rate
for the RTCP timestamp, by calling the <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>SetRTPTimeConversion()</apiname></xref> method </p> </li>
</ul> <p>During an active RTP session, you can change the following parameters: </p> <ul>
<li id="GUID-1A5C1270-11D3-5557-94BE-AAF74ADD2AEC"><p>the destination address,
by calling the <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>SetRemoteAddress()</apiname></xref> method </p> </li>
<li id="GUID-9E2B4415-4D5A-5FB1-96E8-83F9E60944D9"><p>the remote RTCP port,
by calling the <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>SetRemoteRtcpPort()</apiname></xref> method </p> </li>
</ul> <p>When specifying a new remote address for the RTP session, the remote
RTCP port is set one port higher than the RTP port, as defined by the RTP
standard. When specifying a new RTCP port, the RTP port is not modified. </p> <p> <b>Note</b>:
If you need more configuration options for your RTP communications, you can
change the settings of the internal sockets. The <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>RtpSocket()</apiname></xref> and <xref href="GUID-97FC8566-E4AD-3881-8669-134798A88779.dita"><apiname>RtcpSocket()</apiname></xref> methods return the handles of
the internal sockets used for RTP and RTCP data. </p> </section>
<section><title>Example</title> <p>The following code shows how to create
a new session, and set session parameters. </p> <codeblock id="GUID-8AA5C199-15D4-5259-92DC-4389C3F40C2E" xml:space="preserve">// [...]

// Construct a new session object 
RRtpSession session; 
session.OpenL(iRtpSocket, 1500, EPriorityNormal); 

// Set the RTP session parameters 
session.SetBandwidth(1000);    // Set session bandwidth in bps at the start up 

//SetRTPTimeConversion API is called before receiving an RTP packet
session.SetRTPTimeConversion(100, 100); // Set RTP time conversion for generating the RTP timestamps in RTCP packets
</codeblock> <p>The following code shows how to change parameters during the
RTP session: </p> <codeblock id="GUID-745688FD-A148-5668-A962-64985A952EB1" xml:space="preserve">
// sample address and port for the RTP socket
TSockAddr newAddr;
newAddrr.SetAddress(INET_ADDR(192,168,0,1));
newAddr.SetPort(4646);

// changing the RTP destination
session.SetRemoteAddress(newAddr);

// by default, the RTCP port is set to the first port higher than the RTP port 
session.SetRemoteRtcpPort(4649);

// turning IMCP errors onsession.
RtpSocket().SetOpt(KSoUdpReceiveICMPError, KSolInetUdp, 1);
</codeblock> </section>
</conbody></concept>