Re: I-D Action: draft-ietf-bfd-yang-06.txt

Jeffrey Haas <jhaas@pfrc.org> Tue, 01 August 2017 14:38 UTC

Return-Path: <jhaas@slice.pfrc.org>
X-Original-To: rtg-bfd@ietfa.amsl.com
Delivered-To: rtg-bfd@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id AC3A013218E; Tue, 1 Aug 2017 07:38:27 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.903
X-Spam-Level:
X-Spam-Status: No, score=-1.903 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RP_MATCHES_RCVD=-0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id EzWihBRmbb8i; Tue, 1 Aug 2017 07:38:27 -0700 (PDT)
Received: from slice.pfrc.org (slice.pfrc.org [67.207.130.108]) by ietfa.amsl.com (Postfix) with ESMTP id EA7F013218D; Tue, 1 Aug 2017 07:38:26 -0700 (PDT)
Received: by slice.pfrc.org (Postfix, from userid 1001) id C02571E37E; Tue, 1 Aug 2017 10:38:40 -0400 (EDT)
Date: Tue, 1 Aug 2017 10:38:40 -0400
From: Jeffrey Haas <jhaas@pfrc.org>
To: Ashesh Mishra <mishra.ashesh@outlook.com>
Cc: Mahesh Jethanandani <mjethanandani@gmail.com>, Yingzhen Qu <yingzhen.qu@huawei.com>, Reshad Rahman <rrahman@cisco.com>, "draft-ietf-ospf-yang@ietf.org" <draft-ietf-ospf-yang@ietf.org>, "rtg-bfd@ietf.org" <rtg-bfd@ietf.org>, "draft-ietf-bfd-yang@ietf.org" <draft-ietf-bfd-yang@ietf.org>
Subject: Re: I-D Action: draft-ietf-bfd-yang-06.txt
Message-ID: <20170801143840.GB24942@pfrc.org>
References: <D59FBE2A.2CEA06%rrahman@cisco.com> <D5A01A7B.BA49E%acee@cisco.com> <C71CC69E-DAE4-49E0-983A-9B2EE9B4CD46@gmail.com> <D5A12762.2D4DB5%rrahman@cisco.com> <E4E310A2-A79C-403E-B68E-A39B76E2C5E0@gmail.com> <773E4FFC-D66A-49E5-A03A-58B7DBA82D90@gmail.com> <20170731170550.GO24942@pfrc.org> <BAF4C9E6-ED02-4E25-89DD-2FA181AF3B72@gmail.com> <3637B198-8F82-4A85-A4A1-4383AF98088D@pfrc.org> <MWHPR01MB27683CC5A6EB131F6F1395C4FAB20@MWHPR01MB2768.prod.exchangelabs.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <MWHPR01MB27683CC5A6EB131F6F1395C4FAB20@MWHPR01MB2768.prod.exchangelabs.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Archived-At: <https://mailarchive.ietf.org/arch/msg/rtg-bfd/amJNEPv5AkF_4sCJUTHcamDXo1Y>
X-BeenThere: rtg-bfd@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: "RTG Area: Bidirectional Forwarding Detection DT" <rtg-bfd.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtg-bfd>, <mailto:rtg-bfd-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/rtg-bfd/>
List-Post: <mailto:rtg-bfd@ietf.org>
List-Help: <mailto:rtg-bfd-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtg-bfd>, <mailto:rtg-bfd-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 01 Aug 2017 14:38:28 -0000

Ashesh,

On Mon, Jul 31, 2017 at 09:39:57PM +0000, Ashesh Mishra wrote:
> From what I understand, the echo intervals have an inverse relationship with their control interval counterparts. Faster echo allows for slower control frame rate. So they are necessarily different values. That said, having never implemented echo mode, I can't comment how they should get grouped in the model.  

Remember that configuration and operational state may not be the same.  So,
some rampant speculation:

You configure a desired interval of 50ms.  Both sides support echo.
(Remember that support may be asymmetric.)

It's then permissable for the implementation to decide it can only support
100ms in async mode and bid for 100ms async, 50ms echo.  Once Up, the
session may further backoff its async to something slower.

So, the real question is when echo is supported, what do implementations
supporting that put in their async vs. echo intervals?

-- Jeff