Subject: Use and Definition of Path Down Diagnostic Code

From: "O'Connor, Don" <[email-masked]>
Date: Wed, 2 May 2007 17:19:43 -0500

Dave

I have a question of clarification on the use and definition of the Path Down Diagnostic Code

Is this code only used for the case of

"If signaling is received from outside BFD that the underlying path has failed, an implementation MAY administratively disable the session with the diagnostic Path Down."

The definition of Concatenated Path Down 

"Concatenated Path Down and Reverse Concatenated Path Down.  The first propagates forward path failures (in which the concatenated path fails in the direction toward the interworking system)

implies that Concatenated Path Down is a unidirectional failure indication.

So is Path Down also a unidirectional failure indication? More specifically does receipt of a Path Down diagnostic code indicate that the underlying path has failed in the same direction as the received Path Down Diagnostic Code ?

It may be useful to add some additional clarification of the use and definition of Path Down to the next draft of bfd-base

Regards

Don