Hi Sam,

Typo in my email indeed. What I meant is that there could be vendor specific 
extensions if needed.

Also looks like there was confusion in the design team (seemingly caused by my 
misinterpretation of what was said), there is no known implementation which 
supports multiple BFD single-hop sessions for the same pair of endpoints (right 
Santosh?). For MH it's a different story because of multiple-paths.

The DT will get together to clarify and apologies for the confusion.

Regards,
Reshad.

From: Sam Aldrin <[email protected]<mailto:[email protected]>>
Date: Tuesday, November 3, 2015 at 2:48 AM
To: Reshad <[email protected]<mailto:[email protected]>>
Cc: Santosh P K <[email protected]<mailto:[email protected]>>, Gregory 
Mirsky <[email protected]<mailto:[email protected]>>, 
"[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Multiple BFD sessions between the same pair of end-points

Reshad,

On Nov 2, 2015, at 9:29 PM, Reshad Rahman (rrahman) 
<[email protected]<mailto:[email protected]>> wrote:

Hi Santosh,

Even for single-hop we had discussions about implementations which support the 
option of having multiple BFD single-hop sessions on 1 interface between 2  
endpoints. That was an argument for having the BFD config in routing 
applications. This is what was discussed today in the WG. And I think Greg's 
point is that we don't have to support this in the base model, but 
implementations are have vendor specific model which supports this behavior.
Are there already vendor specific models/implementations in the single hop 
case? OR did you mean, there could be vendor specific extensions?

-sam

Regards,
Reshad.


From: Rtg-bfd <[email protected]<mailto:[email protected]>> on 
behalf of Santosh P K <[email protected]<mailto:[email protected]>>
Date: Tuesday, November 3, 2015 at 1:25 AM
To: Gregory Mirsky 
<[email protected]<mailto:[email protected]>>, 
"[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: RE: Multiple BFD sessions between the same pair of end-points

This is form RFC 5881 section 3.

In this application, there will be only a single BFD session between
   two systems over a given interface (logical or physical) for a
   particular protocol.  The BFD session must be bound to this
   interface.

Which says for singlehop you will have only single BFD session for an 
interface.  The case where we are struggling in Yang is for multihop BFD 
session.

Thanks
Santosh P K


From: Rtg-bfd [mailto:[email protected]] On Behalf Of Gregory Mirsky
Sent: Tuesday, November 03, 2015 7:57 AM
To: [email protected]<mailto:[email protected]>
Subject: Multiple BFD sessions between the same pair of end-points

Dear All,
I think that this paragraph from Section 2 of RFC 5881 prohibits multiple 
single-hop BFD sessions between the same pair of end points:
   Each BFD session between a pair of systems MUST traverse a separate
   network-layer path in both directions.  This is necessary for
   demultiplexing to work properly, and also because (by definition)
   multiple sessions would otherwise be protecting the same path.

                Regards,
                                Greg

Reply via email to