title: RIL_REQUEST_SETUP_DATA_CALL Params
body: <p>I'm doing some work on RIL, and I am a little confused about <strong>RIL_REQUEST_SETUP_DATA_CALL</strong> and <strong>RIL_REQUEST_SET_INITIAL_ATTACH_APN</strong> requests.</p>
  
  <p>I know that if we change the APN setting, the request RIL_REQUEST_SET_INITIAL_ATTACH_APN will be dispatched immediately.
  And I think that only "setting->APN" can configure APN setting by a user. And there is only one APN for a mobile(regardless mms APN). Then if I setup a data call the APN should be this one.</p>
  
  <p>So does anyone knows that Why the param of RIL_REQUEST_SETUP_DATA_CALL request contains APN? I think is useless and it should be the same APN in RIL_REQUEST_SET_INITIAL_ATTACH_APN request. Thanks!</p>
  
  <p>The following is comments of param for RIL_REQUEST_SETUP_DATA_CALL.</p>
  
  <pre><code> * "data" is a const char **
   * ((const char **)data)[0] Radio technology to use
   * ((const char **)data)[1] is a RIL_DataProfile
   * ((const char **)data)[2] is the APN to connect
   * ((const char **)data)[3] is the username for APN, or NULL
   * ((const char **)data)[4] is the password for APN, or NULL
   * ((const char **)data)[5] is the PAP / CHAP auth type. Values:
  </code></pre>