Re: RTT Storage

[Phil Karn <karn@unix.ka9q.ampr.org>]

Lots of dynamically-aquired stuff could be stored to disk and reloaded
at reboot: TCP RTTs, NET/ROM routing tables, AX.25 heard lists, ARP
caches, etc. Maybe this is already being done in some of the other
variants of my code; I don't know. But you also have to be careful
that it doesn't do you more harm than good, considering that the stuff
might be way out of date when you restart.

The importance of an accurate TCP RTT depends on the raw packet loss
rate.  If it's low enough, then the absolute value of the accuracy of
your estimate of RTT isn't nearly as important as being sure that it's
larger than the actual value to prevent unnecessary
retransmissions. For most Internet paths, the 5 second starting value
is more than enough, but I guess ham packet radio is different.

Phil