RFC 1030 (rfc1030) - Page 2 of 16

On testing the NETBLT Protocol over divers networks

RFC 1030              Testing the NETBLT Protocol          November 1987


   helped monitor it during testing.

3. Implementations and Test Programs

   This section briefly describes the NETBLT implementations and test
   programs used in the testing.  Currently, NETBLT runs on three
   machine types: Symbolics LISP machines, IBM PC/ATs, and SUN-3s.  The
   test results described in this paper were gathered using the IBM
   PC/AT and SUN-3 NETBLT implementations.  The IBM and SUN
   implementations are very similar; most differences lie in timer and
   multi-tasking library implementations.  The SUN NETBLT implementation
   uses UNIX's user-accessible raw IP socket; it is not implemented in
   the UNIX kernel.

   The test application performs a simple memory-to-memory transfer of
   an arbitrary amount of data.  All data are actually allocated by the
   application, given to the protocol layer, and copied into NETBLT
   packets.  The results are therefore fairly realistic and, with
   appropriately large amounts of buffering, could be attained by disk-
   based applications as well.

   The test application provides several parameters that can be varied
   to alter NETBLT's performance characteristics.  The most important of
   these parameters are:


        burst interval  The number of milliseconds from the start of one
                        burst transmission to the start of the next burst
                        transmission.


        burst size      The number of packets transmitted per burst.


        buffer size     The number of bytes in a NETBLT buffer (all
                        buffers must be the same size, save the last,
                        which can be any size required to complete the
                        transfer).


        data packet size
                        The number of bytes contained in a NETBLT DATA
                        packet's data segment.


        number of outstanding buffers
                       The number of buffers which can be in
                       transmission/error recovery at any given moment.



M. Lambert