RE: Status of Operational issues with Tiny Fragments in IPv6

["Templin, Fred L" <Fred.L.Templin@boeing.com>]

> There is a discussion of fragmentation and reassembly in RFC 1812  
> section 4.2.2.7 that may be useful to reference, or at least learn  
> lessons from. In part, this results from the behavior of NIC cards in

> the late 1980's that couldn't reliably receive datagrams back to back

> for very long due to chip or memory issues,

Digital Equipment Corporation had such NIC cards in the
late 1980's. The DEQNA card in particular could go into
"qe restart" mode when it received back to back fragments
that arrived too quickly for its little legs to carry.
This was exacerbated by packetization mechanisms such as
NFS that sent 8KB frames as chains of back-to-back IPv4
fragments. The follow-on DELQA card, as well as "faster"
VAX processors, improved the situation.    

> and partly this is is due  
> to brain-dead behaviors in early end-station OS's.

Having authored some of the network drivers in one of
those "brain-dead" OSs, there was really nothing that
could be done for the DEQNA case. Ethernet of that day
and age was supposed to be 10Mb/sec, but SUN was one
of the first vendors that could actually achieve
that rate. Times have certainly changed.

Fred
fred.l.templin@boeing.com