Subject: Basic clarification on BFD session setup

From: [email-masked]
Date: Fri, 02 Jul 2010 05:20:31 -0400

All,
 
I have been looking into BFD drafts recently and have the following basic queries. Would appreciate clarification.
 
Firstly, the base draft states - "A session begins with the periodic, slow transmission of BFD Control
packets". My interpretation of this is that during session establishment, the configured DesiredMinTxInterval and the transmit interval (max of DesiredMinTx and RemoteMinRx) determined thereof will not be used. Instead some fixed default value that would result in a slow rate so as not to hog the bandwidth, should be used. That is the actual negotiated transmit interval is actually used only after session establishment (UP state) for the periodic transmission of BFD control packets. Is this right?
 
Further from the bfd for mpls draft, it looks like the LSP ping echo request is to be immediately replied by a BFD control packet without necessarily being sent on the next periodic transmission. This seems unlike the base draft (as quoted above - slow "periodic" transmission). Or have I got this wrong?
 
Cheers
Lucy