[tcpm] Comments for draft-ietf-tcpm-rfc8312bis-02
Yoshifumi Nishida <nsd.ietf@gmail.com> Tue, 01 June 2021 08:35 UTC
Return-Path: <nsd.ietf@gmail.com>
X-Original-To: tcpm@ietfa.amsl.com
Delivered-To: tcpm@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 788FE3A040C for <tcpm@ietfa.amsl.com>; Tue, 1 Jun 2021 01:35:27 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.096
X-Spam-Level:
X-Spam-Status: No, score=-2.096 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.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 wRUTRk9ztnBQ for <tcpm@ietfa.amsl.com>; Tue, 1 Jun 2021 01:35:23 -0700 (PDT)
Received: from mail-qk1-x732.google.com (mail-qk1-x732.google.com [IPv6:2607:f8b0:4864:20::732]) (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 D4AD33A040A for <tcpm@ietf.org>; Tue, 1 Jun 2021 01:35:22 -0700 (PDT)
Received: by mail-qk1-x732.google.com with SMTP id v8so13470143qkv.1 for <tcpm@ietf.org>; Tue, 01 Jun 2021 01:35:22 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=JRryeugH2fKnAlfDuJUGeUXfofcla/3Jt9WYAR0x58Y=; b=p5zoIDfaUqUfuT7AgQouRpZbExTKXvbMLHoxhe4kfybhedsnxV1a5jIrjDXbs/eJTQ m2YNw6tP7WdlL9BhnR58DzlVisCWvD+QmdQ7dSQ67yoIZMErDw14VYsUrE+WL+I3u4i+ YRsevZWwGt6X5e58S0I27GvgVXdjmMJDy/JYWEiGNBUpXYzh02j3Pn0M95o79fQugiFB dO8mWVVAYlSGELIDjL2PIn+X+1OBpkyN8tRw/sBrQMhIfgvKmUCi000pwvjqEJ/JQ+Sv HKcrMWRbhzjMbnIpnM+I3V4KOHTFZxz2wy4eWrkm0dYRh4dBCwt6qQCMVhelXrWQbtxK sP5g==
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; bh=JRryeugH2fKnAlfDuJUGeUXfofcla/3Jt9WYAR0x58Y=; b=fOVeV53sDRquoPIu7UEglOLgJ+n94yBo9kyoUsEMD2bIX+IMaeQKm30Gg/EkxlEi9O ShIc6YHEADdPOiuJuxJ0O6j1/MNsdeqLIT+0ZclEmr2/8v2QuWThkbiXm7hS++RM6ot+ kX6jGSCBY5CUVrJEdZkU9xvon5fwWRiwo9Pov78kTqZaK3N/wb/IC92lm3/uH9gCEdGq Zd9eLo7gdrOM2+7/XcgR641TKKu7ACV9YUG8EwHLhB8tDdgo1ggng6uSNJdZsM/1QlHo Qn1kFsi3BDwpNwtMZJBjf9z0kHCPm6w1EhJQ4Eh9qowR7QH/v+2sG7UCm/FtNY7MjD1W udFA==
X-Gm-Message-State: AOAM530A/1iSv0q6QTvHtGvx3/4YYJxOUethVwUJIL0YIUcxHX8Veu1O ThCF0/CPrb75jJhttmQtzP+UgoM8agrpxkGj6mCQKDyoXUU=
X-Google-Smtp-Source: ABdhPJzAWmOIvPzV2Xjpqs71K0rzvfIATz89IFq9aJb37OFDBO337vT2YJROh8UiAxF3tpOsnKCx0ac3x+nWzAY28SI=
X-Received: by 2002:a37:2c07:: with SMTP id s7mr1614135qkh.454.1622536520594; Tue, 01 Jun 2021 01:35:20 -0700 (PDT)
MIME-Version: 1.0
References: <CAAK044Q6Xy72-xsNdJ5yP0PDdo08N9zmAWickf13788E4u8cJw@mail.gmail.com> <CAAK044TxNs1B3VA1NzEgXyCRXSb8MHSNKkXeac2UFstQu7e8Mg@mail.gmail.com>
In-Reply-To: <CAAK044TxNs1B3VA1NzEgXyCRXSb8MHSNKkXeac2UFstQu7e8Mg@mail.gmail.com>
From: Yoshifumi Nishida <nsd.ietf@gmail.com>
Date: Tue, 01 Jun 2021 01:35:09 -0700
Message-ID: <CAAK044QSo-0E_QHWDqrDE2VLEzOFEA4SxnHSX9DSKvSg-8y+pg@mail.gmail.com>
To: "tcpm@ietf.org Extensions" <tcpm@ietf.org>
Content-Type: multipart/alternative; boundary="000000000000f1f86105c3b03899"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tcpm/W-t1q8q6Q0Ofjcp0iXOgmY18mr0>
Subject: [tcpm] Comments for draft-ietf-tcpm-rfc8312bis-02
X-BeenThere: tcpm@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: TCP Maintenance and Minor Extensions Working Group <tcpm.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tcpm>, <mailto:tcpm-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tcpm/>
List-Post: <mailto:tcpm@ietf.org>
List-Help: <mailto:tcpm-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tcpm>, <mailto:tcpm-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 01 Jun 2021 08:35:28 -0000
Hello, I have the following comments on this draft. 1: While this draft focuses on only TCP, CUBIC can actually be applied to other transport protocols such as QUIC, SCTP. Do we want to mention it in the draft or is it out of scope? 2: Section 3.1 "After a window reduction in response to a congestion event is detected by duplicate ACKs or Explicit Congestion Notification-Echo (ECN-Echo, ECE) ACKs [RFC3168 <https://datatracker.ietf.org/doc/html/rfc3168>], CUBIC remembers the congestion window..." I think the events detected by RACK (or PTO for QUIC) can also be included here. 3: Section 4.1.1 It seems that the text version of the draft uses b_cubic and a_aimd, while the pdf version of the draft uses different names. But, I prefer to use the same names in both versions to avoid confusion. 4: Section 4.2 I personally prefer to refer the equations in the draft as 'Equation' rather than 'Figure' if there's no strong reason for it. 5: Section 4.3 It seems to me that there are two meanings for a_aimd in this section. One is the additive factor for CUBIC and the other is a generic parameter for AIMD() function. This looks a bit confusing to me. 6: Section 4.3 The description for P is required for Figure 3. 7: Section 4.3 I think The analysis in [FHP00] doesn't include delayed ACK factor. So, the AIMD TCP model here can be a bit aggressive compared to a TCP that doesn't enable ABC and uses delayed ACK. This is fine, but I think it might be good to clarify it. 8: Section 4.3 I am not very sure why segments_acked is used rather than byted_acked here. What is the benefit of it? How do we calculate when the acks are split? Also, I think it should be clarified that cwnd is expressed in segments here in this case. 9: Section 4.3 "Note that once _W_est_ reaches _W_max_, that is, _W_est_ >= _W_max_, ..." I might miss something, but I'm not sure why a_aimd can be set to 1 to be compatible with AIMD TCP. Does this mean b_cubic is also updated? If not, why this can be compatible? 10: Section 4.5: " The convex profile ensure that the window increases very slowly at the beginning.." I am wondering how much this part is accurate. Because of Principal 2, even though cwnd is increased through convex profile, I think it will be overridden by linear growth by AIMD. 11: Section 4.7: "we update w_max as follows, before the window reduction as described in section 4.6" I am wondering if reducing w_max is the right approach here. Because if we reduce w_max, CUBIC can exit from convex region earlier than the case where fast convergence is not used. It seems to me that keeping w_max and reducing only cwnd (using smaller value than b_cubic) look more conservative. 12: Section 5.2 and Section 5.3. Do these results are based on the algorithms and the parameter values described in the draft? If there're differences, I think it should be described. Thanks, -- Yoshi On Thu, May 13, 2021 at 1:19 AM Yoshifumi Nishida <nsd.ietf@gmail.com> wrote: > Hi, > > Sorry. The link for the draft was not correct. Please use this one. > https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-rfc8312bis-02 > -- > Yoshi > > On Thu, May 13, 2021 at 12:57 AM Yoshifumi Nishida <nsd.ietf@gmail.com> > wrote: > >> Hello everyone, >> >> This e-mail initiates the WGLC for >> https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-rfc8312bis-01 >> Please send your feedback to the ML. >> This WGLC runs until * Monday Jun 6 * >> >> The intended status of the draft is Proposed Standard. >> We appreciate your cooperation. >> >> Thanks, >> -- >> tcpm-chairs >> >>
- [tcpm] WGLC for draft-ietf-tcpm-rfc8312bis-01 Yoshifumi Nishida
- Re: [tcpm] WGLC for draft-ietf-tcpm-rfc8312bis-01 Yoshifumi Nishida
- [tcpm] Comments for draft-ietf-tcpm-rfc8312bis-02 Yoshifumi Nishida
- Re: [tcpm] Comments for draft-ietf-tcpm-rfc8312bi… Lars Eggert
- Re: [tcpm] Comments for draft-ietf-tcpm-rfc8312bi… Vidhi Goel
- Re: [tcpm] Comments for draft-ietf-tcpm-rfc8312bi… Vidhi Goel
- Re: [tcpm] Comments for draft-ietf-tcpm-rfc8312bi… Jonathan Morton