12 <concept xml:lang="en" id="GUID-F43A54C0-E82B-5790-8493-1372D214C642"><title>What are Planes</title><shortdesc>This topic describes the concept of a <i>Plane</i> in the Communications Framework. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody><p>The transmission of data and the management of connections is divided into separate operations. Symbian OS gives the name <i>Plane</i> to these operations. The Communications Framework defines three Planes. Each Plane has a separate role and a separate responsibility. Each Plane matches a Sockets Server API. </p> <p>The Planes are called: the Data Plane, the Control Plane and the Management Plane. </p> <p>Layers span all three Planes. Code in each Plane operates together to deliver the required Communications protocol behaviour. </p> <p>A connection can have a number of subconnections. Subconnections can be called channels. The concepts of connection and subconnection make it useful to divide the Control Plane into two parts. The following diagram shows the concept. The blue arrows indicate dependencies. The vertical dotted lines indicate the division of Planes. </p> <fig id="GUID-258000D9-1BC3-5A61-8235-4183D4A759C5"><title>

    12 <concept id="GUID-F43A54C0-E82B-5790-8493-1372D214C642" xml:lang="en"><title>What

    13           Planes in the Communications Framework

    13 are Planes</title><shortdesc>This topic describes the concept of a <i>Plane</i> in the Communications

    14         </title> <image href="GUID-3D8FE2A7-E544-51B9-9572-492A3B61377C_d0e88010_href.png" placement="inline"/></fig> <p>The following diagram overlays the Planes with an example series of Layers </p> <fig id="GUID-1758E53D-2A62-5C4C-93B9-8FE5DE67BBAA"><title>

    14 Framework. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    15           Planes and Layers in the Communications Framework

    15 <p>The transmission of data and the management of connections is divided into

    16         </title> <image href="GUID-47EF98E9-7833-5E94-ADFF-198401463A8C_d0e88019_href.png" placement="inline"/></fig> <ul><li id="GUID-45F19CFA-9B96-53B3-9B15-428BB3226BAA"><p> <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-E8250BBE-8529-5C45-BCA3-92A87C013580">Data Plane</xref>  </p> </li> <li id="GUID-461678D6-3198-55CF-B07E-94F5E1086BAC"><p> <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-CFFC0BC1-FD9D-5F82-8906-2F9E8FCD21F5">Control Plane</xref>  </p> </li> <li id="GUID-6B98DEAB-F245-5533-A05A-957FADE0C120"><p> <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-2372FF88-FA59-5CDF-9362-1A54F43D8442">Management Plane</xref>  </p> </li> </ul> <section id="GUID-E8250BBE-8529-5C45-BCA3-92A87C013580"><title>Data Plane</title> <p>The Data Plane carries data and uses Communications protocols. The Data Plane handles conversations with remote peers.The <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-CFFC0BC1-FD9D-5F82-8906-2F9E8FCD21F5">Control Plane</xref> and the <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-2372FF88-FA59-5CDF-9362-1A54F43D8442">Management Plane</xref> exist to serve the Data Plane. </p> <p>The Data Plane exists to minimise interruptions to the flow of data. The Data Plane assigns the response to interruptions to the Control Plane. Interruptions include: the start of a new network connection, the management of a timeout and the management of changes to the status of the network. </p> <p>To make sure that interruptions cannot interfere with the Data Plane, a thread divide exists between the Data Plane and the Control/Management Planes. The thread division allows the Communications Framework to give the Data Plane thread a higher priority than the Control and Management Plane thread. The difference in thread priorities allows the Communications Framework to give the task of data transfer the highest priority. </p> <p>The Communications Framework provides a mechanism to send messages between the threads. The mechanism is called the <xref href="GUID-4CE10DED-31B2-50B5-9D38-85CE86E8A8DE.dita">Message Transport</xref>. The Transport sends and delivers the messages asynchronously. Threads can continue their work until the threads are prepared to process messages. The Transport always makes sure of the delivery of messages. </p> <p>The Data Plane corresponds to the Sockets Server API: <xref href="GUID-D4F08503-F1EF-3531-9C3C-4AF24A6255F0.dita"><apiname>RSocket</apiname></xref>. </p> <p>The following diagram shows the thread divide. </p> <fig id="GUID-A440C4F8-199E-575A-9922-D90059CA69C3"><title>

    16 separate operations. Symbian platform gives the name <i>Plane</i> to

    17              Data Plane in the Communications Framework

    17 these operations. The Communications Framework defines three Planes. Each

    18           </title> <image href="GUID-337FA49D-DE53-5568-9A5C-D6AE3F25E0A6_d0e88086_href.png" placement="inline"/></fig> <p><b>Features </b> </p> <p>The Data Plane: </p> <ul><li id="GUID-70DDF365-81B9-5D30-BEA1-B338074CF097"><p>exchanges data with remote peers and uses data transfer protocols </p> </li> <li id="GUID-E8A426F5-98AD-5BFA-9D8C-820B1656140C"><p>allows any number of conversations at the same time through many protocols </p> </li> <li id="GUID-6748E1E2-5FF3-52BC-9FC7-6759F52B59D2"><p>enables the transfer of data to clients of the protocol stack and from clients of the protocol stack </p> </li> <li id="GUID-1073D70B-80FA-55E7-96E9-C9B51A701BC4"><p>enables the transfer of data to hardware and from hardware </p> </li> </ul> </section> <section id="GUID-CFFC0BC1-FD9D-5F82-8906-2F9E8FCD21F5"><title>Control Plane</title> <p>The Control Plane establishes, maintains and modifies the traffic, or conversations in the Data Plane. Specifically, the Control Pane establishes, controls, re-binds and tears down the Communications protocol stack based on commands from the application and from the Management Plane. </p> <p>The <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-E8250BBE-8529-5C45-BCA3-92A87C013580">Data Plane</xref> sends the status of the link and other control information to the Control Plane. The Control Plane processes the status of the link and other control information, and allows the Data Plane to give the task of data transfer the highest priority. </p> <p>A connection can have a number of subconnections. Subconnections can be called channels. The concepts of connection and subconnection make it useful to divide the Control Plane into two parts. </p> <p>The Data Plane corresponds to the Sockets Server APIs: <xref href="GUID-BED8A733-2ED7-31AD-A911-C1F4707C67FD.dita"><apiname>RConnection</apiname></xref> and <xref href="GUID-0AFDA357-EE44-3788-9CAB-162B874134BF.dita"><apiname>RSubConnection</apiname></xref>. </p> <p><b>Features </b> </p> <p>The Control Plane: </p> <ul><li id="GUID-EE232AB1-E916-54AB-B658-19B1A3F62B7C"><p>creates the Data Plane </p> </li> <li id="GUID-F5E545D5-7954-5F20-B8A4-4C9B7F4B06CC"><p>configures the Data Plane modules from information provided by the client application or the Management Plane </p> </li> <li id="GUID-3C4FF301-30D7-5064-BD45-5A05C962E1DE"><p>starts the Data Plane </p> </li> <li id="GUID-BB2A8489-38D7-5D0B-A272-0C04DDE9B2FF"><p>controls and monitors the Data Plane: </p> <ul><li id="GUID-7D7E7B38-34C4-53F6-A545-774DEEE07403"><p>acts on information received from the data protocols </p> </li> <li id="GUID-805AE125-F139-5E65-9912-DCA92926F1EF"><p>notifies the Management Plane or the client application about changes to the state of the Control Plane or the Data Plane. </p> </li> </ul> </li> <li id="GUID-ACDF9227-7286-5092-AF85-503BA30A2B45"><p>stops the Data Plane </p> </li> <li id="GUID-54C50C8C-4CFB-5C02-89CE-754EF2F858E2"><p>destroys the Data Plane </p> </li> <li id="GUID-8FC8ED8A-71DA-546A-8548-D6979B0F8CD7"><p>manages connection session timers </p> </li> <li id="GUID-C316844B-3046-599E-967C-085D79F9DA01"><p>manages connection data channels and their properties </p> </li> <li id="GUID-7CF74684-F4C8-54FC-9BA0-EA68D081E5AF"><p>handles changes to the status of the network and handles error reports </p> </li> </ul> </section> <section id="GUID-2372FF88-FA59-5CDF-9362-1A54F43D8442"><title>Management Plane</title> <p>The Management Plane maintains the configuration of the device, monitors the availability of the network and makes policy decisions for the Communications Framework. The Management Plane is the main location where phone creators can customise the behaviour of the Communications protocol stack. </p> <p>The Management Plane corresponds to the Sockets Server API: <xref href="GUID-55FE59B7-4FA9-3B1A-BD4C-9B7611FE75C2.dita"><apiname>RConnectionServ</apiname></xref>  </p> <p><b>Features </b> </p> <p>The Management Plane: </p> <ul><li id="GUID-3FB67172-7DC3-5621-AADB-02AE601D4EAF"><p>selects, constructs and manages the Communications protocol stack: </p> <ul><li id="GUID-003EFE03-849E-5168-AAC3-8CFB6E07436C"><p>selects the correct protocol stack for a connection based on client and configuration preferences </p> </li> <li id="GUID-2E1CBE6C-2CCE-51E7-AE9C-F4EFAC0A426B"><p>manages the Control Plane connections based on the policy set either in the configuration or at run-time. </p> </li> </ul> </li> <li id="GUID-DA0FE037-69DB-586D-8809-C4D5A8D22C67"><p>notifies interested clients about the state of the Communications protocol stack, for example, bearer and service availability </p> </li> <li id="GUID-3B36F963-CCF5-5E75-9486-04CBEF27DFC1"><p>provides an entry point for third-party plugins to customise and control the Communications protocol stack </p> </li> <li id="GUID-D7A39FA9-1C88-5E8E-A566-E030971CCF0A"><p>controls the Communications protocol stack. This control is based on policy decisions </p> </li> <li id="GUID-8BBADB62-AB50-5B9D-B0E8-9546488E12DD"><p>communicates with the Control Plane to influence the behaviour of Control or Data flow operations in the Communications protocol stack </p> </li> <li id="GUID-86CAD544-2B60-5713-B8C1-1FB14806FC31"><p>supplies configuration information to the Layer. </p> </li> </ul> </section> </conbody><related-links><link href="GUID-61E0CD76-A2E3-5066-84A8-146EECA8ADCD.dita"><linktext>Socket Server</linktext> </link> </related-links></concept>

    18 Plane has a separate role and a separate responsibility. Each Plane matches

    19 a Sockets Server API. </p>

    20 <p>The Planes are called: the Data Plane, the Control Plane and the Management

    21 Plane. </p>

    22 <p>Layers span all three Planes. Code in each Plane operates together to deliver

    23 the required Communications protocol behaviour. </p>

    24 <p>A connection can have a number of subconnections. Subconnections can be

    25 called channels. The concepts of connection and subconnection make it useful

    26 to divide the Control Plane into two parts. The following diagram shows the

    27 concept. The blue arrows indicate dependencies. The vertical dotted lines

    28 indicate the division of Planes. </p>

    29 <fig id="GUID-258000D9-1BC3-5A61-8235-4183D4A759C5">

    30 <title>           Planes in the Communications Framework         </title>

    31 <image href="GUID-3D8FE2A7-E544-51B9-9572-492A3B61377C_d0e111498_href.png" placement="inline"/>

    32 </fig>

    33 <p>The following diagram overlays the Planes with an example series of Layers </p>

    34 <fig id="GUID-1758E53D-2A62-5C4C-93B9-8FE5DE67BBAA">

    35 <title>           Planes and Layers in the Communications Framework      

    36   </title>

    37 <image href="GUID-47EF98E9-7833-5E94-ADFF-198401463A8C_d0e111509_href.png" placement="inline"/>

    38 </fig>

    39 <ul>

    40 <li id="GUID-45F19CFA-9B96-53B3-9B15-428BB3226BAA"><p> <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-E8250BBE-8529-5C45-BCA3-92A87C013580">Data Plane</xref>  </p> </li>

    41 <li id="GUID-461678D6-3198-55CF-B07E-94F5E1086BAC"><p> <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-CFFC0BC1-FD9D-5F82-8906-2F9E8FCD21F5">Control Plane</xref>  </p> </li>

    42 <li id="GUID-6B98DEAB-F245-5533-A05A-957FADE0C120"><p> <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-2372FF88-FA59-5CDF-9362-1A54F43D8442">Management Plane</xref>  </p> </li>

    43 </ul>

    44 <section id="GUID-E8250BBE-8529-5C45-BCA3-92A87C013580"><title>Data Plane</title> <p>The

    45 Data Plane carries data and uses Communications protocols. The Data Plane

    46 handles conversations with remote peers.The <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-CFFC0BC1-FD9D-5F82-8906-2F9E8FCD21F5">Control

    47 Plane</xref> and the <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-2372FF88-FA59-5CDF-9362-1A54F43D8442">Management

    48 Plane</xref> exist to serve the Data Plane. </p> <p>The Data Plane exists

    49 to minimise interruptions to the flow of data. The Data Plane assigns the

    50 response to interruptions to the Control Plane. Interruptions include: the

    51 start of a new network connection, the management of a timeout and the management

    52 of changes to the status of the network. </p> <p>To make sure that interruptions

    53 cannot interfere with the Data Plane, a thread divide exists between the Data

    54 Plane and the Control/Management Planes. The thread division allows the Communications

    55 Framework to give the Data Plane thread a higher priority than the Control

    56 and Management Plane thread. The difference in thread priorities allows the

    57 Communications Framework to give the task of data transfer the highest priority. </p> <p>The

    58 Communications Framework provides a mechanism to send messages between the

    59 threads. The mechanism is called the <xref href="GUID-4CE10DED-31B2-50B5-9D38-85CE86E8A8DE.dita">Message

    60 Transport</xref>. The Transport sends and delivers the messages asynchronously.

    61 Threads can continue their work until the threads are prepared to process

    62 messages. The Transport always makes sure of the delivery of messages. </p> <p>The

    63 Data Plane corresponds to the Sockets Server API: <xref href="GUID-D4F08503-F1EF-3531-9C3C-4AF24A6255F0.dita"><apiname>RSocket</apiname></xref>. </p> <p>The

    64 following diagram shows the thread divide. </p> <fig id="GUID-A440C4F8-199E-575A-9922-D90059CA69C3">

    65 <title>              Data Plane in the Communications Framework           </title>

    66 <image href="GUID-337FA49D-DE53-5568-9A5C-D6AE3F25E0A6_d0e111579_href.png" placement="inline"/>

    67 </fig> <p><b>Features </b> </p> <p>The Data Plane: </p> <ul>

    68 <li id="GUID-70DDF365-81B9-5D30-BEA1-B338074CF097"><p>exchanges data with

    69 remote peers and uses data transfer protocols </p> </li>

    70 <li id="GUID-E8A426F5-98AD-5BFA-9D8C-820B1656140C"><p>allows any number of

    71 conversations at the same time through many protocols </p> </li>

    72 <li id="GUID-6748E1E2-5FF3-52BC-9FC7-6759F52B59D2"><p>enables the transfer

    73 of data to clients of the protocol stack and from clients of the protocol

    74 stack </p> </li>

    75 <li id="GUID-1073D70B-80FA-55E7-96E9-C9B51A701BC4"><p>enables the transfer

    76 of data to hardware and from hardware </p> </li>

    77 </ul> </section>

    78 <section id="GUID-CFFC0BC1-FD9D-5F82-8906-2F9E8FCD21F5"><title>Control Plane</title> <p>The

    79 Control Plane establishes, maintains and modifies the traffic, or conversations

    80 in the Data Plane. Specifically, the Control Pane establishes, controls, re-binds

    81 and tears down the Communications protocol stack based on commands from the

    82 application and from the Management Plane. </p> <p>The <xref href="GUID-F43A54C0-E82B-5790-8493-1372D214C642.dita#GUID-F43A54C0-E82B-5790-8493-1372D214C642/GUID-E8250BBE-8529-5C45-BCA3-92A87C013580">Data Plane</xref> sends the status of the link and other control information

    83 to the Control Plane. The Control Plane processes the status of the link and

    84 other control information, and allows the Data Plane to give the task of data

    85 transfer the highest priority. </p> <p>A connection can have a number of subconnections.

    86 Subconnections can be called channels. The concepts of connection and subconnection

    87 make it useful to divide the Control Plane into two parts. </p> <p>The Data

    88 Plane corresponds to the Sockets Server APIs: <xref href="GUID-BED8A733-2ED7-31AD-A911-C1F4707C67FD.dita"><apiname>RConnection</apiname></xref> and <xref href="GUID-0AFDA357-EE44-3788-9CAB-162B874134BF.dita"><apiname>RSubConnection</apiname></xref>. </p> <p><b>Features </b> </p> <p>The Control Plane: </p> <ul>

    89 <li id="GUID-EE232AB1-E916-54AB-B658-19B1A3F62B7C"><p>creates the Data Plane </p> </li>

    90 <li id="GUID-F5E545D5-7954-5F20-B8A4-4C9B7F4B06CC"><p>configures the Data

    91 Plane modules from information provided by the client application or the Management

    92 Plane </p> </li>

    93 <li id="GUID-3C4FF301-30D7-5064-BD45-5A05C962E1DE"><p>starts the Data Plane </p> </li>

    94 <li id="GUID-BB2A8489-38D7-5D0B-A272-0C04DDE9B2FF"><p>controls and monitors

    95 the Data Plane: </p> <ul>

    96 <li id="GUID-7D7E7B38-34C4-53F6-A545-774DEEE07403"><p>acts on information

    97 received from the data protocols </p> </li>

    98 <li id="GUID-805AE125-F139-5E65-9912-DCA92926F1EF"><p>notifies the Management

    99 Plane or the client application about changes to the state of the Control

   100 Plane or the Data Plane. </p> </li>

   101 </ul> </li>

   102 <li id="GUID-ACDF9227-7286-5092-AF85-503BA30A2B45"><p>stops the Data Plane </p> </li>

   103 <li id="GUID-54C50C8C-4CFB-5C02-89CE-754EF2F858E2"><p>destroys the Data Plane </p> </li>

   104 <li id="GUID-8FC8ED8A-71DA-546A-8548-D6979B0F8CD7"><p>manages connection session

   105 timers </p> </li>

   106 <li id="GUID-C316844B-3046-599E-967C-085D79F9DA01"><p>manages connection data

   107 channels and their properties </p> </li>

   108 <li id="GUID-7CF74684-F4C8-54FC-9BA0-EA68D081E5AF"><p>handles changes to the

   109 status of the network and handles error reports </p> </li>

   110 </ul> </section>

   111 <section id="GUID-2372FF88-FA59-5CDF-9362-1A54F43D8442"><title>Management

   112 Plane</title> <p>The Management Plane maintains the configuration of the device,

   113 monitors the availability of the network and makes policy decisions for the

   114 Communications Framework. The Management Plane is the main location where

   115 phone creators can customise the behaviour of the Communications protocol

   116 stack. </p> <p>The Management Plane corresponds to the Sockets Server API: <xref href="GUID-55FE59B7-4FA9-3B1A-BD4C-9B7611FE75C2.dita"><apiname>RConnectionServ</apiname></xref>  </p> <p><b>Features </b> </p> <p>The Management Plane: </p> <ul>

   117 <li id="GUID-3FB67172-7DC3-5621-AADB-02AE601D4EAF"><p>selects, constructs

   118 and manages the Communications protocol stack: </p> <ul>

   119 <li id="GUID-003EFE03-849E-5168-AAC3-8CFB6E07436C"><p>selects the correct

   120 protocol stack for a connection based on client and configuration preferences </p> </li>

   121 <li id="GUID-2E1CBE6C-2CCE-51E7-AE9C-F4EFAC0A426B"><p>manages the Control

   122 Plane connections based on the policy set either in the configuration or at

   123 run-time. </p> </li>

   124 </ul> </li>

   125 <li id="GUID-DA0FE037-69DB-586D-8809-C4D5A8D22C67"><p>notifies interested

   126 clients about the state of the Communications protocol stack, for example,

   127 bearer and service availability </p> </li>

   128 <li id="GUID-3B36F963-CCF5-5E75-9486-04CBEF27DFC1"><p>provides an entry point

   129 for third-party plugins to customise and control the Communications protocol

   130 stack </p> </li>

   131 <li id="GUID-D7A39FA9-1C88-5E8E-A566-E030971CCF0A"><p>controls the Communications

   132 protocol stack. This control is based on policy decisions </p> </li>

   133 <li id="GUID-8BBADB62-AB50-5B9D-B0E8-9546488E12DD"><p>communicates with the

   134 Control Plane to influence the behaviour of Control or Data flow operations

   135 in the Communications protocol stack </p> </li>

   136 <li id="GUID-86CAD544-2B60-5713-B8C1-1FB14806FC31"><p>supplies configuration

   137 information to the Layer. </p> </li>

   138 </ul> </section>

   139 </conbody><related-links>

   140 <link href="GUID-61E0CD76-A2E3-5066-84A8-146EECA8ADCD.dita"><linktext>Socket Server</linktext>

   141 </link>

   142 </related-links></concept>