ged SRTP session. </p>
<p>For user-managed SRTP session (flag RCE_SRTP_KMNGMNT_USER), the media stream is not started until SRTP key has been added and all calls to <a class="el" href="#a157e9973d92b65e82914d4028690c770" title="Send data to remote participant with a custom timestamp.">push_frame()</a> will fail.</p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramname">key</td><td>SRTP master key, default is 128-bit long </td></tr>
    <tr><td class="paramname">sa