RFC 102 (rfc102) - Page 2 of 4

Output of the Host-Host Protocol glitch cleaning committee

RFC 102       HOST/HOST PROTOCOL GLITCH CLEANING COMMITTEE February 1971


   Specific Recommendations

   1. The ECO and ERP command should each be 8 bits long.

   2. The ERR command should be 96 bits long.

   3. Message Data Types should be eliminated.  Third-level protocol
      people may reinstate such a mechanism.

   4. The Cease mechanism should be discontinued.

   5. A new pair of one byte commands RST (reset) and RRP (reset reply)
      should be added.  The RST should be interpreted as a signal to
      purge the NCP tables of any existing entries which arose from the
      sending Host.  The RRP command should be returned to acknowledge
      receipt of the RST.  The Host sending the RST may proceed after
      receiving either a RST or a RRP in return.  A RST may be returned
      if the second Host comes up after the first Host.

   6. Although it was suggested at the Urbana meeting that connections
      should be full-duplex, the committee recommends against this
      change.

   7. Messages should be an integral number of bytes, and the number of
      bytes and the byte size should be specified in each message.  The
      marking convention should be abandoned and the padding ignored.

      The number of bytes in the message should be a 16-bit number
      following the leader.  The byte size should be in the next 8-bit
      field.  Two suggestions were generated for the starting point of
      the text, and these are explained in the next session.

      For flow control purposes, the number of bits in a message is the
      product of the number of bytes and the byte size.  The leader and
      other fixed format fields are not counted.

   8. The problem of synchronizing the interrupt signal in a console
      input stream was considered.  We consider the console input
      scanner as a process and note two reasonable implementations: it
      may either read characters as fast as it can, looking for the
      interrupt character and throwing away characters if there is no
      room in the user process' input queue; it may read characters only
      as fast as the user process can receive them, (or at least has
      room for them).

   The first implementation guarantees that the interrupt character
   (e.g., control - C on the PDP-10 10/50) will always be acted on, but
   requires that the using process interpret the output stream to detect



Crocker