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

[Alper Yegin <alper.yegin@samsung.com>]

> >    Node's establishment of a link-layer connection with an
attachment
> >    point that signifies the availability of IP service (i.e., being
able
> >    to send and receive IP packets) between the two is considered a
link
> >    up event.
> 
> Does this preclude "Link Up" from being sent on a uni-directional
link?
> In other words, must the link layer demonstrate bi-directional
> reachability prior to sending a "Link Up" event?

We haven't really considered uni-directional links... Hmmm, should DNA
deal with that?

Assuming we are only talking about bi-directional links, I presume the
reachability test would be performed implicitly (e.g., 4-way handshake)
or explicitly by the L2. 

Alper