If the remote DTLS fingerprint has been changed or the tls-id has
      changed, tear down the DTLS connection.  This includes the case
      when the PeerConnection state is "have-remote-pranswer".  If a
      DTLS connection needs to be torn down but the answer does not
      indicate an ICE restart or, in the case of "have-remote-pranswer",
      new ICE credentials, an error MUST be generated.  If an ICE
      restart is performed without a change in tls-id or fingerprint,
      then the same DTLS connection is continued over the new ICE
      channel.  Note that although JSEP requires that answerers change
      the tls-id value if and only if the offerer does, non-JSEP
      answerers are permitted to change the tls-id as long as the offer
      contained an ICE restart.  Thus, JSEP implementations which
      process DTLS data prior to receiving an answer MUST be prepared to
      receive either a ClientHello or data from the previous DTLS
      connection.