Re: [Lsr] Doubt regarding A bit set/clear
Gurusiddesh Nidasesi <gurusiddesh.nidasesi@ipinfusion.com> Fri, 23 April 2021 13:34 UTC
Return-Path: <gurusiddesh.nidasesi@ipinfusion.com>
X-Original-To: lsr@ietfa.amsl.com
Delivered-To: lsr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C0BB73A0906 for <lsr@ietfa.amsl.com>; Fri, 23 Apr 2021 06:34:28 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.699
X-Spam-Level:
X-Spam-Status: No, score=-1.699 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=no autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=neutral reason="invalid (public key: invalid data)" header.d=ipinfusion.com
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 B3EhlTdL1Rpw for <lsr@ietfa.amsl.com>; Fri, 23 Apr 2021 06:34:23 -0700 (PDT)
Received: from mail-lj1-x22b.google.com (mail-lj1-x22b.google.com [IPv6:2a00:1450:4864:20::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 308FB3A08EA for <lsr@ietf.org>; Fri, 23 Apr 2021 06:34:22 -0700 (PDT)
Received: by mail-lj1-x22b.google.com with SMTP id m7so44884404ljp.10 for <lsr@ietf.org>; Fri, 23 Apr 2021 06:34:22 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ipinfusion.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Ys1FNi334RmYsTsKijFvLNf1/3RNQeji/1fhhIBuaC8=; b=dQFP4gTDbKG35+8Jt+e0hFF8cp2sjeZefHLB7iFrT0F65YrfNhCHmlxVzC83LZNmJK zJQoSMg+h80/S87fYRqezmjgRGSZpx7qfN9SXiTCKQIZ5xzhnUfVhBuMDv5wannkFLeJ MPHLZdXXk2wuZMqIF2fo6SOThEiK5U5JK+/MzGCUKea83yGLhCCiK0Z3hFghPkEFQLd0 SxIvVcaICDB1EHvO1YPfAAlkCs4IMW0ARBLdLBedhlinCi/i7kpdk+I/YIO+kWC+x5bz GzHCMB/uwgzG3ZgLTUxSsei2YS1CHTv+Q3iRzY9Cl23lIZDZBJLrlAGBS5dC4NwwlS0R uNSw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Ys1FNi334RmYsTsKijFvLNf1/3RNQeji/1fhhIBuaC8=; b=AXTuhKb/B2usyfomYW8dvJjJOOd+L9/ilpCQLsIGk+Cz7dzkjLQo/Nh7muOYU+OCno HKlHN+ZcG0VOG+HCG4uhZgUW3tdrLD8aXoj6NNaUMVrei1K3Skowm+R3PF8wo6gXS74f KCuI/ywZswTQTpLcnWXGMxC1Lu74rg7bXSUIidDcx/EdfpqK0oSbhn92X3s96NJ2o6X4 yyQFRTmx7E8qeDhFI2nCZDBhBkKxQN2e0WH3l3fC2upGTl9ThmJk5swQeXYo7rbAQLQa 5VFrkH3bCQeL8kcC18GLZiw4u6efquABSykRLDq7mJpKzkBQztubupSXvPVizfmBZBMr 9lag==
X-Gm-Message-State: AOAM532kaje1XgHHMwgVTm8evxbc724HsGwMAkVoxuWcFK/uVzY+j6yJ VSFqGtUrcJcAiFQrFbEgbpZRqFm9CnER8jZdFZOXJawRCltMrkGyG45WRP15e+SOYAloF5rmiJk dWWHU6yMM2mX/C+x13Rf8/1ZR8f8ZVpoKe8oQQ7b8sh8g/E8Tqkd8sBQICNumt1qOIp5XpLOdjZ c2boyTos4OK3yyIAI=
X-Google-Smtp-Source: ABdhPJyAy0b/eYbXBdlL8jl7Ow6ZNSyfBybAQkdKfg1Ot+ayzQjk/x1zAqURFpy7KS2ypig2TY6yQ86PhpqKdqH3QAc=
X-Received: by 2002:a2e:b88c:: with SMTP id r12mr2826626ljp.212.1619184859798; Fri, 23 Apr 2021 06:34:19 -0700 (PDT)
MIME-Version: 1.0
References: <C8D3F1D2-728D-4DE2-98FA-3155716DF241@cisco.com> <CAHhGMfGJbs8mgV6OrnPQ+r-ziL5VMOMiPF+w-3D1SfhX_UTTSg@mail.gmail.com> <BY5PR11MB433786C2E674B1EE849E65B2C1459@BY5PR11MB4337.namprd11.prod.outlook.com> <CAHhGMfGcKj=SoG0HWJ9RTaCP6NhSXEkOroVOSX16Hm+-rhTJmQ@mail.gmail.com> <BY5PR11MB4337657416846A492383FDB4C1459@BY5PR11MB4337.namprd11.prod.outlook.com>
In-Reply-To: <BY5PR11MB4337657416846A492383FDB4C1459@BY5PR11MB4337.namprd11.prod.outlook.com>
From: Gurusiddesh Nidasesi <gurusiddesh.nidasesi@ipinfusion.com>
Date: Fri, 23 Apr 2021 19:04:07 +0530
Message-ID: <CAHhGMfEEZih2QZ_RP3BK6kPP5_q6eNnZS8do0GrO0R+eLyn4ag@mail.gmail.com>
To: "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>
Cc: "Acee Lindem (acee)" <acee@cisco.com>, "lsr@ietf.org" <lsr@ietf.org>, "spencer.giacalone@gmail.com" <spencer.giacalone@gmail.com>, "stefano@previdi.net" <stefano@previdi.net>, Dona Maria John <dona.john@ipinfusion.com>, Vikram Agrawal <vikram.agrawal@ipinfusion.com>, Mahalakshmi Kumar <mahalakshmi.udhaya@ipinfusion.com>
Content-Type: multipart/alternative; boundary="00000000000064fe1505c0a3da0b"
Archived-At: <https://mailarchive.ietf.org/arch/msg/lsr/CB6C25hCleqIkmjsyKE1A2nKUs0>
Subject: Re: [Lsr] Doubt regarding A bit set/clear
X-BeenThere: lsr@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Link State Routing Working Group <lsr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/lsr>, <mailto:lsr-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/lsr/>
List-Post: <mailto:lsr@ietf.org>
List-Help: <mailto:lsr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/lsr>, <mailto:lsr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 23 Apr 2021 13:34:35 -0000
Hi Les, Thanks for the quick response and confirmation. Regards, Gurusiddesh V N On Fri, Apr 23, 2021 at 7:00 PM Les Ginsberg (ginsberg) <ginsberg@cisco.com> wrote: > Gurusiddesh - > > > > *From:* Gurusiddesh Nidasesi <gurusiddesh.nidasesi@ipinfusion.com> > *Sent:* Friday, April 23, 2021 5:58 AM > *To:* Les Ginsberg (ginsberg) <ginsberg@cisco.com> > *Cc:* Acee Lindem (acee) <acee@cisco.com>; lsr@ietf.org; > spencer.giacalone@gmail.com; stefano@previdi.net; Dona Maria John < > dona.john@ipinfusion.com>; Vikram Agrawal <vikram.agrawal@ipinfusion.com>; > Mahalakshmi Kumar <mahalakshmi.udhaya@ipinfusion.com> > *Subject:* Re: [Lsr] Doubt regarding A bit set/clear > > > > Hi Les, > > > > Thank you very much for your response. > > On top of your response, I have a few more queries. Please find them below. > > > > 1. For *Min/Max Unidirectional Link Delay Sub-TLV, *there is only one > *A-bit.* > > 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > > | Type | Length | > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > > |A| RESERVED | Min Delay | > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > > | RESERVED | Max Delay | > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > > > > Does this mean A-bit is applicable only for Min-delay? > > *[Les:] The RFC states in Section 4.2 (emphasis added):* > > > > *“A bit: This field represents the Anomalous (A) bit. The A bit is* > > * set when one or more measured values exceed a configured maximum* > > * threshold…”* > > > > *I think the rest you can figure out for yourself.* > > > > * Les* > > > > > > > > IF not, then should we maintain 2 different maximum threshold and reuse thresholds? > > And if both min-delay and max-delay values fall below reuse threshold we have clear A-bit. > > > > Will below example follow the RFC? > min-delay reuse threshold : 50 usec > min-delay maximum threshold : 100 usec > > max-delay reuse threshold : 200 usec > max-delay maximum threshold : 300 usec > > > > *1st measured value:* > > min-delay: 110 usec > > max-delay: 190 usec > > > conclusion: Set A bit. (As min-delay value has exceeded max-threshold value?) > > *2nd measured value :* > > min-delay: 40 usec > > max-delay: 320 usec > > > > conclusion : Do nothing (Maintain pervious state of A bit as max-delay value has exceeded max-threshold value?) > > *3rd measured value :* > > min-delay: 40 usec > > max-delay: 150 usec > > conclusion : Clear A bit (As both min-delay and max-delay values are falling below resue threshold?) > > > > Thanks & Regards, > > Gurusiddesh V N > > > > > > On Fri, Apr 23, 2021 at 4:51 PM Les Ginsberg (ginsberg) < > ginsberg@cisco.com> wrote: > > Gurusiddesh – > > > > The short answer to all your questions is “yes”. > > More inline. > > > > *From:* Gurusiddesh Nidasesi <gurusiddesh.nidasesi@ipinfusion.com> > *Sent:* Thursday, April 22, 2021 10:33 PM > *To:* Acee Lindem (acee) <acee@cisco.com> > *Cc:* lsr@ietf.org; spencer.giacalone@gmail.com; stefano@previdi.net; Les > Ginsberg (ginsberg) <ginsberg@cisco.com>; Dona Maria John < > dona.john@ipinfusion.com>; Vikram Agrawal <vikram.agrawal@ipinfusion.com>; > Mahalakshmi Kumar <mahalakshmi.udhaya@ipinfusion.com> > *Subject:* Re: [Lsr] Doubt regarding A bit set/clear > > > > Hi All. > > > > *Gentle Reminder!* > > > > Regards, > > Gurusiddesh V N > > > > On Mon, Apr 19, 2021 at 6:54 PM Acee Lindem (acee) <acee@cisco.com> wrote: > > Gurusiddesh, > > > > I’ll defer to the RFC authors on your question. However, please refrain > from referring to bits as being “unset”. They are set or clear. > > > > Thanks, > > Acee > > > > *From: *Lsr <lsr-bounces@ietf.org> on behalf of Gurusiddesh Nidasesi < > gurusiddesh.nidasesi@ipinfusion.com> > *Date: *Monday, April 19, 2021 at 6:13 AM > *To: *"lsr@ietf.org" <lsr@ietf.org> > *Cc: *Spencer Giacalone <spencer.giacalone@gmail.com>, Stefano Previdi < > stefano@previdi.net>, "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>, > Dona Maria John <dona.john@ipinfusion.com>, Vikram Agrawal < > vikram.agrawal@ipinfusion.com>, Mahalakshmi Kumar < > mahalakshmi.udhaya@ipinfusion.com> > *Subject: *[Lsr] Doubt regarding A bit set/unset > > > > Hi All, > > > > I had a query regarding setting/unsetting A bit. > > > > https://tools.ietf.org/html/rfc8570#section-4.1 states that > > A bit: This field represents the Anomalous (A) bit. The A bit is > > set when the measured value of this parameter exceeds its > > configured maximum threshold. The A bit is cleared when the > > measured value falls below its configured reuse threshold. If the > > A bit is cleared, the sub-TLV represents steady-state link > > performance. > > > > So does it mean we have to have two configurations one for reuse and another for maximum threshold? > > *[Les:] Yes. The goal is to prevent altering the advertisement due to small oscillations of the advertisement. If you had a single value then if the measured value bounced between (for example) +1/-1 of the threshold) the advertisement of the A-bit would change rapidly – this is undesirable.* > > *So the max threshold triggers setting of the A-bit and the reuse threshold triggers clearing of the bit. The reuse threshold provides some confidence that the measurement has stabilized below the maximum anomalous threshold.* > > > > > > Will below example follow the RFC? > > reuse threshold : 50 usec > > maximum threshold : 100 usec > > 1st measured value : 110 usec > > conclusion: Set A bit. > > > > 2nd measured value : 75 usec > > conclusion : Do nothing (Maintain pervious state of A bit as the value is less than reuse or greater than threshold) > > > > 3rd measurement value : 30 usec > > conclusion: Unset A bit. > > > > *[Les:] Yes this conforms to specified behavior.* > > > > If we have to have two configuration for threshold to set/unset A bit, will they be different from the threshold that we use for advertisements? > > *[Les:] **Yes . ** This is clearly stated in Section 5:* > > > > *“4. For sub-TLVs that include an A bit, an additional threshold* > > * SHOULD be included corresponding to the threshold for which the* > > * performance is considered anomalous (and sub-TLVs with the A bit* > > * are sent)…”* > > * Les* > > > > > > > > Regards, > > Gurusiddesh V N > > > . > > > > > -- > > Thanks, > > Gurusiddesh V N > > > . > > > > > -- > > Thanks, > > Gurusiddesh V N > > > . > -- Thanks, Gurusiddesh V N -- .
- Re: [Lsr] Doubt regarding A bit set/clear Acee Lindem (acee)
- Re: [Lsr] Doubt regarding A bit set/clear Gurusiddesh Nidasesi
- Re: [Lsr] Doubt regarding A bit set/clear Les Ginsberg (ginsberg)
- Re: [Lsr] Doubt regarding A bit set/clear Gurusiddesh Nidasesi
- Re: [Lsr] Doubt regarding A bit set/clear Les Ginsberg (ginsberg)
- Re: [Lsr] Doubt regarding A bit set/clear Gurusiddesh Nidasesi