Re: [DNA] Definition of "Link Up" and "Link Down" events?

[James Kempf <kempf@docomolabs-usa.com>]

Eric,


I have a little problem with the most recent defintion (Bernard's) of
Link-Down suggested. The statement "A Link Down event is only generated once
the link layer considers the link unusable" looks (to me at least) a bit
contradictory to the first sentence of the definition in the sense that the
link layer can consider the link unusable even without any change having
occured in the link state machine: PDP context activated in GPRS/UMTS but
very high BER
Said differently, the definition implies that the event cause can be "state
changed" in the link layer state machine as well "state did not changed" (as
the link can become unusable within the same state) which is a problem.

Hope my concern is understood.

Insn't
"An event provided by the link layer that signifies a state change
associated with the interface no longer being capable of communicating IP
packets. transient periods of high frame loss are not sufficient." enough
for Link down definition?

Please advice

jak>> I guess I don't understand the problem. The definition leaves it up to
the link layer to decide what "unusable" means. Whether or not that involves
a state machine change or some other consideration is pretty much up to the
link layer to decide.

            jak