 
       else if m = line.match(/a=rtcp-mux/)
         # enable rtcp muxing in the dtls srtp stack
-        stream.dtls_srtp.rtcp_mux = true
+        stream.transport.rtcp_mux = true
 
       else if m = line.match(/a=candidate:(.*)/)
         # add incoming candidates to libnice

        # remove fingerprint, we add our own above
        remove_line()

      i++

    for id, stream of @streams
      stream.nice.setRemoteCredentials(stream.ufrag ? global.ufrag, stream.pwd ? global.pwd)
      stream.nice.gatherCandidates()

      stream.dtls_srtp.setRtpPayloads(rtp_types)

    answer = lines.join('\r\n')


    console.log 'closing echo'
    for _, stream of @streams
      stream.nice.close()
      stream.transport.close()

