implementing a heartbeat for tramp

[Matthew Kennedy]

A router I have to work through frequently seems to kill inactive ssh
sessions after a few minutes for no apparent reason.  If I'm using
tramp with one of the ssh or scp methods, then this means my tramp
connection is killed, causing tramp to reconnect automatically and go
though its time-consuming initialization phase.

Based on my very effective hack where I run "xclock -update 10" to
cause some activity on the connection every 10 seconds during remote
shell sessions, I thought I might attempt something similar with
tramp... call it a "tramp heart-beat" if you will.

My idea was to create a timer, which walked all emacs buffers looking
for tramp buffers.  When it found one, it would (maybe)
`tramp-send-command' to send a heart-beat (I guess some kind of null
operation... touch /dev/null??? -- or maybe the command itself
suffices)

Does this sound reasonable?  Any other ways to approach this problem
perhaps?

Matt
-- 
Matthew Kennedy