RFC 467 (rfc467) - Page 3 of 7

Proposed change to Host-Host Protocol: Resynchronization of connection status

RFC 467                                                    February 1973


      2.) Wait until the message pipeline is empty, i.e. until a RFNM
      has been received for each regular message sent over this
      connection.  This synchronizes the control and data activity, and
      also assures that the data stream will not be corrupted during the
      control re-synchronization exchange.

      3.) Send the RCS command.

      4.) Continue to process allocates normally, updating the variables
      which indicate outstanding bit and message allocation.

   When the receiving NCP receives the RCS, it should:

      1.) Zero the variables indicating outstanding bit and message
      allocation.

      2.) Reset the connection to the state which indicates readiness to
      accept a message.

      3.) Confirm the re-synchronization by sending the RCR reply.

      4.) Reconsider bit and message allocation, and send an ALL command
      for any allocation it cares to do.

   When the sending host receives the RCR reply, it should:

      1.) Zero the variables indicating outstanding bit and message
      allocate.

      2.) Put the connection into the "ready-to-send-message" state in
      preparation for any forthcoming ALL commands.

   At this point, the "pipeline" contains no messages and no allocates,
   and the outstanding allocation variables at both ends are in
   agreement. (With value zero)

IV. Resynchronization By Receiver

   The re-synchronization sequence may be triggered by the receiving
   NCP.  Such resynchronization could be initiated manually by TIP and
   TELNET users who are expecting output but receiving none.  Again
   assuming that allocation has been lost, the appropriate action is to
   reset the connection by sending an RCR command.  This action is also
   appropriate if an inconsistent event occurs with respect to the
   connection.  (e.g. arrival of a message which exceeds allocation).






Burchfiel