section RSP
  description   The responses which can be received/send on SIP level.
  message 200(OK) SIP method has been handled succesful.
  message 202(Accepted) SIP MESSAGE has been processed and accepted.
  message 400(Bad-Request) A failure occured in the request
  message 403(Forbidden) SIP MESSAGE rejected as it is not allowed (license).
  message 4xx Indicates any error.
  protocol SIP SIP - Protocol description.