Re: Convert /etc/hosts to RR format pgm anyone? [unrelated]


Philip A. Prindeville (philipp@Larry.McRCIM.McGill.EDU)
Sun, 12 Jun 88 18:33:26 EDT


        FRAME - lowest level of bits/bytes. One speaks of Ethernet Frames, etc
                A FRAME has ONE data link header (e.g. Ethernet header).

        FRAGMENT - the thing that IP spits out to the data link driver. Each
                   FRAGMENT has ONE IP header. A FRAGMENT may be split into
                   multiple FRAMES by the lower layers.

Not quite. A DATAGRAM becomes fragmented (in FRAGMENTS, of course) so that
each will fit into a FRAME. The whole purpose of the MTU and fragmentation
is to avoid lower level fragmentation and reassembly. The only exception to
this is X.25 where you have complete-packet-sequences (but since X.25
is reliable, and in order, this doesn't present a problem). Under LAN
technologies (ARCNET, PRONET, Ethernet, Token Ring, etc) 1 FRAGMENT ==
1 FRAME.

        [ ... ]

        DATAGRAM - this is also the 'larger' thing that IP tries to send. A
                   DATAGRAM USUALLY has a one to one relationship with a SEGMENT
                   It may be broken up (fragmented) into a number of FRAGMENTS
                   by IP before being sent through the data link.

Yes.

-Philip



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