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

From: NJEDJOU Eric RD-RESA-REN <[email-masked]>
Date: Thu, 02 Jun 2005 17:47:19 +0200

Bernard, 
That whas exactly my concern. Good that you are ok whith taking out the second statement of the definition
Eric Njejdou

-----Message d'origine-----
De : [email-masked] [mailto:[email-masked]] De la part de Bernard Aboba
Envoyé : jeudi 2 juin 2005 17:16
À : James Kempf
Cc : [email-masked]
Objet : Re: [DNA] Definition of "Link Up" and "Link Down" events?

> "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?

The above is ok from my point of view.

> jak>> I guess I don't understand the problem. The definition leaves it 
> jak>> 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.

I think Erik's point was that we don't want a "Link Down" to be sent just because a few frames were lost.  While that might initiate a search for a new point of attachment, the problem might be highly transient.  Where there is multi-link interference, for example, we see the S/N ratio drop 20-30 dB within a very short distance.