[net.unix-wizards] 4.2 TCP, large packets and pronet-drivers

creon@ames-nas-gw.arpa (08/06/84)

From:  Creon Levit <creon@ames-nas-gw.arpa>

One thing to look at is the illegal (according to the tcp/ip spec.) use
of shorts and signed ints where unsigned ints should be used.  This was
a problem in sending large (4KB) hyperchanne packets via tcp/ip in
4.2bsd.
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dave@uwvax.ARPA (08/07/84)

I got a number of replies to my question.  This one pretty much says
it all:

> Sure, we had this problem.  The problem is that the 4.2 code seems to
> decide randomly whether to use trailers or not (actually, it's not
> random, but I don't understand the algorithm - only large packets
> will be sent with trailers, though...)  If your gateways don't
> understand trailer protocols (as ours don't), then the large
> packets sent with trailers will never get through.
> 
> Our limited experience with trailers was that they made essentially
> no difference in throughput at any time on any type of connection,
> so we just turned them off.
> 					-Larry Allen

-- 
Dave Cohrs @ wisconsin
...!{allegra,heurikon,ihnp4,seismo,ucbvax,uwm-evax}!uwvax!dave
dave@wisc-rsch.arpa