RE: Re: draft-suping-bfd-mpls-fecmismatch-00 questions

["David Allan" <[e-mail]>]

It is not detecting a control plane failure, it is detecting inconsistencies
in forwarding such that synch between control and data plane has been lost..
connectivity to somewhere exists but is not necessarily correct...IMO that
is still a data plane problem...

Dave

> -----Original Message-----
> From: [e-mail] 
> [mailto:[e-mail]] On Behalf Of David Ward
> Sent: Sunday, February 27, 2005 10:48 AM
> To: zhaisuping
> Cc: [e-mail]
> Subject: Re: Re: draft-suping-bfd-mpls-fecmismatch-00 questions
> 
> 
> Unfort., what you write is 180 degrees opposite from the 
> charter of the BFD WG and the philosophy of how the protocol 
> is to function. BFD is not to check the consistency of the 
> forwarding and control plane. We do not want to 
> take this protocol into the realm of control plane failure 
> detection system (as there are many better protocols or 
> protocol machinery for that) but,  focus on forwarding 
> failure detection that can send alarms, event notification, 
> diags, etc up the stack.
> 
> 
> -DWard
> 
> 
> 
> On Sat, Feb 26, 2005 at 09:41:49AM +0800, zhaisuping wrote:
> > Hi, all
> > The purpose of FEC filter in BFD is to detect the consistence of
> > the control plane and data plane. So that in the MPLS network, just
> > running the BFD session(LSP-Ping is not needed) is enough for the
> > defect detection. Or else such tools as LSP-Ping is needed because
> > the BFD session can't detect the inconsistence of the control plane
> > and data plane. 
> > In the section 2 of the draft, there is description of the 
> > problem the draft want to solve.
> > >> Wouldn't LSP-Ping (or VCCV) be a more appropriate place 
> to do this 
> > >> filter verification?
> > 
> > 
> > >
> > >LSP-Ping does a verification on the FEC itself, so a 
> filter would add 
> > >nothing.
> > >
> > >VCCV is not a protocol.  Just a little sideband for sending IP 
> > >packets down a pseudowire so that you can run LSP-Ping, BFD, etc. 
> > >between the two ends.
> > >
> > >....George
> > >
> > 
> >=============================================================
> ===========
> > >George Swallow             Cisco Systems                  
> [phone]
> > >                           1414 Massachusetts Avenue
> > >                           Boxborough, MA 01719
> 
> 
>