[e2e] tcp keepalive 2 hour default

[tom worster]

does anyone here know the historical rationale for the two
hour minimum on the default tcp keep-alive specified in 
rfc1122?

    Keep-alive packets MUST only be sent when no data or
    acknowledgement packets have been received for the
    connection within an interval.  This interval MUST be
    configurable and MUST default to no less than two hours.

why was two hours chosen?

c u
fsb