p≡p passive mode

  1. call config_passive_mode(session, true) on all sessions of the transports using passive mode
  2. for outgoing messages, convert X-pEp-Version in .opt_fields conforming to the signalling concept of the message on the line
  3. for incoming messages, implement the conversion of the signalling in the line format of the message to X-pEp-Version in .opt_fields.