From nobody Wed Feb 9 08:30:42 2022 Return-Path: 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 5D7EF3A059F for ; Wed, 9 Feb 2022 08:30:40 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -2.098 X-Spam-Level: X-Spam-Status: No, score=-2.098 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, SPF_HELO_NONE=0.001, SPF_PASS=-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 izgW8yh2qyI1 for ; Wed, 9 Feb 2022 08:30:36 -0800 (PST) Received: from mail-qt1-x832.google.com (mail-qt1-x832.google.com [IPv6:2607:f8b0:4864:20::832]) (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 E36613A040B for ; Wed, 9 Feb 2022 08:30:35 -0800 (PST) Received: by mail-qt1-x832.google.com with SMTP id t1so2215541qtq.13 for ; Wed, 09 Feb 2022 08:30:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:from:date:message-id:subject:to; bh=MKsx35PUh45JEKcnaLZGgtbNoLgby7krimIrqrWDzxQ=; b=MTrMYeuhIvrsp/jMTWpCmTxV/lzaYtFcGpIaCaxmqT9P9hTwBZGokInPG7eYEqT0Rc CNhkDbZtEzD1Exqq05fZmuOBS6Qk1onnpzcTe7CxISI6xSJftz0K1OW4yDyM84KH6573 MUwWsN2nr8lFVsS56iLpMSr2HsKV3ewZNfL1/wDEcpwPZA5DhV0waiXU2XMIUvO/CWf4 X4dnHCZI/lMFpwepbh17DqxHDnz6QY+Xlqjye4BnmI/xH1SXOMYTzZpETc2xx2YEwnxP ziuPjHvWpEY5KwertyloAvHc9DdKVZgNC0UhphS7sTBcFWEpm20ciBXjQQn1mqxSQ2q4 o7Vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=MKsx35PUh45JEKcnaLZGgtbNoLgby7krimIrqrWDzxQ=; b=Xo9S0MynXdJ2vv14lka3oZDZNZ0Rbr/SWi+owVa11339/xB2cyZ0GqwdUo3VxjOVtx lwdKOvDlFYbip1Li1YOBMs6dv/RVwv3B+gMU4CQFdkFzAJlcLAcK9ad/AvMqp3Ocd9ju nSXz8TgsQfMDPBtxwcG+wntVz6RdxIY/+s6CIHFFxJPpqxFGmj+ym4/KYB10k4KP9zx3 q1s4XZPUA93BQDWYdjtJmNO+BYMukOqISfCyZx6r6yw0dUwMwROmUq/DLq79Sfxf/iLm sKC7j+SJ2zaRmOWnWpoxDmtS6hMZoBtkfsWqZsoh/1Iz7/vcmIHqDP8wg6GfaMRl1+eM u3XQ== X-Gm-Message-State: AOAM5319pjPD+xzd3eM7MOGsxi6yWiJU2oYCYaRvQ97Hsg99vDqxgbdf lM/7WHmixa0PRKcR9haNr7WW+R1lUP8JnwEA1m9GEOzCYf4= X-Google-Smtp-Source: ABdhPJzHRUTrFtym6CkJz4Fc9p0dNGRDJf7obmYsb5ntcz3e4by19A/k1OfrOJvfDBVQ1s7MvKzzZ8cRf9GFQquDBOU= X-Received: by 2002:a05:622a:174d:: with SMTP id l13mr1930428qtk.55.1644424233482; Wed, 09 Feb 2022 08:30:33 -0800 (PST) MIME-Version: 1.0 From: Yoshifumi Nishida Date: Wed, 9 Feb 2022 08:30:22 -0800 Message-ID: To: "tcpm@ietf.org Extensions" Content-Type: multipart/alternative; boundary="0000000000004bfb7b05d7985a1c" Archived-At: Subject: [tcpm] comments on draft-ietf-tcpm-prr-rfc6937bis-01 X-BeenThere: tcpm@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: TCP Maintenance and Minor Extensions Working Group List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Feb 2022 16:30:41 -0000 --0000000000004bfb7b05d7985a1c Content-Type: text/plain; charset="UTF-8" Hi, I have the following comments on draft-ietf-tcpm-prr-rfc6937bis-01 1: Page 5 "but recommended to use BBR-SSRB" -> PRR-SSRB? 2: Page 7 "and do what? @@@@" -> Please add more texts or remove this. 3: Page 8: """ prr_delivered = 0 // Total bytes delivered during recovery prr_out = 0 // Total bytes sent during recovery """ -> I personally think "during recovery" might be a bit ambiguous. I think it would be better to clarify whether this includes a packet sent by fast retransmit or not. 4: Page 8: " pipe = (RFC 6675 pipe algorithm) " -> The algorithm here seems to depend on SACK, but the draft also states: "It is most accurate and more easily implemented with SACK [RFC2018 ], but does not require SACK." I think It is not clear how this algorithm works without SACK. 5: Section 7 Page 9 Why all examples shown here use Limited Transmit even though PRR doesn't require it? I think there should be some explanations for it even if there's no strong reason. 6: Page 10: It seems that the pipe size in the figure is different from what RFC6675 calculates because Section 5 (4.2) in RFC6675 mentions " note that [RFC5681 ] requires that any segments sent as part of the Limited Transmit mechanism not be counted in FlightSize for the purpose of the above equation. Hence, I think the pipe size would be something like this if it follows RFC6675. Please let me know if I miss something. 6675 ack# X 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 cwnd: 20 20 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 pipe: 19 19 19 18 17 16 15 14 13 12 11 10 09 09 09 09 09 09 09 sent: N N R N N N N N N N PRR ack# X 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 pipe: 19 19 18 18 18 17 17 16 16 15 15 14 14 13 13 12 12 11 10 sent: N N R N N N N N N N 6675 ack# X X X X X X X X X X X X X X X 15 16 17 18 19 cwnd: 20 20 10 10 10 pipe: 19 19 4 10 10 sent: N N 6R R R Thanks, -- Yoshi --0000000000004bfb7b05d7985a1c Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi,

I have the following comments on dr= aft-ietf-tcpm-prr-rfc6937bis-01

1: Page 5
=C2=A0 =C2=A0 "but recommended to use BBR-SSRB"
=C2= =A0 =C2=A0 =C2=A0 -> PRR-SSRB?

2: Page 7
<= div>=C2=A0 =C2=A0 "and do what?=C2=A0@@@@"
=C2=A0 =C2= =A0 =C2=A0 -> Please add more texts or remove this.

=
3: Page 8:
=C2=A0 =C2=A0"""
=C2= =A0 =C2=A0 =C2=A0 prr_delivered =3D 0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0// T= otal bytes delivered during recovery
      prr_out =3D 0               // Total bytes sent dur=
ing recovery
=C2=A0 =C2=A0"""
=C2= =A0 =C2=A0 =C2=A0-> I personally think "during recovery" might= be a bit ambiguous. I think it would be better to clarify=C2=A0
= =C2=A0 =C2=A0 =C2=A0 =C2=A0 whether this includes a packet sent by fast ret= ransmit or not.=C2=A0

4: Page 8:
=C2=A0 = " pipe =3D (= RFC 6675 pipe algorithm) "
=C2=A0=C2=A0
=C2=A0 =C2=A0 =C2=A0= -> The algorithm here seems to depend on SACK, but the=C2=A0draft also s= tates:
=C2=A0 =C2=A0 =C2=A0 =C2=A0 "It is most=C2=A0accurate and more easily implemented with SACK [RFC2018], but does=C2=A0= not require SACK."
=C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0I think It is not clear how this algorithm works without SACK.=C2= =A0

5: Section 7 Page 9
=C2=A0 =C2=A0 =C2=A0Wh= y all examples shown here use Limited Transmit even though PRR doesn't = require it?=C2=A0
=C2=A0 =C2=A0 =C2=A0I think there should be som= e explanations for it even if there's no strong reason.

<= /div>

6: Page 10:
=C2=A0 =C2=A0 =C2=A0It seems= that the pipe size in the figure is different from what RFC6675 calculates= because Section 5 (4.2) in RFC6675 mentions
=C2=A0 =C2=A0 "= 
      note that [RFC5681] requires that any
      segments sent as part of the Limited Transmit mechanism not
      be counted in FlightSize for the purpose of the above
      equation.
    
    Hence, I think the pipe size would be something like this if =
it follows RFC6675.
    Please let me know if I miss something.
<= pre style=3D"font-size:13.3333px;margin-top:0px;margin-bottom:0px;break-bef= ore:page;color:rgb(0,0,0)">
6675
=C2=A0 =C2=A0ack# =C2=A0 X =C2=A01 =
=C2=A02 =C2=A03 =C2=A04 =C2=A05 =C2=A06 =C2=A07 =C2=A08 =C2=A09 10 11 12 13=
 14 15 16 17 18 19
=C2=A0 =C2=A0cwnd: =C2=A0 =C2=A020 20 10 10 10 10 10 =
10 10 10 10 10 10 10 10 10 10 10 10
=C2=A0 =C2=A0pipe: =C2=A0 =C2=A019 1=
9 19 18 17 16 15 14 13 12 11 10 09 09 09 09 09 09 09
=C2=A0 =C2=A0sent: =
=C2=A0 =C2=A0 N =C2=A0N =C2=A0R =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 N =C2=A0N =C2=A0N =
=C2=A0N =C2=A0N =C2=A0N =C2=A0N


PRR

=C2=A0 =C2=A0ack# =C2=
=A0 X =C2=A01 =C2=A02 =C2=A03 =C2=A04 =C2=A05 =C2=A06 =C2=A07 =C2=A08 =C2=
=A09 10 11 12 13 14 15 16 17 18 19
=C2=A0 =C2=A0pipe: =C2=A0 =C2=A019 19=
 18 18 18 17 17 16 16 15 15 14 14 13 13 12 12 11 10
=C2=A0 =C2=A0sent: =
=C2=A0 =C2=A0 N =C2=A0N =C2=A0R =C2=A0 =C2=A0 N =C2=A0 =C2=A0 N =C2=A0 =C2=
=A0 N =C2=A0 =C2=A0 N =C2=A0 =C2=A0 N =C2=A0 =C2=A0 N =C2=A0 =C2=A0 N


<=
/pre>
6675
=C2=
=A0 =C2=A0ack# =C2=A0 X =C2=A0X =C2=A0X =C2=A0X =C2=A0X =C2=A0X =C2=A0X =C2=
=A0X =C2=A0X =C2=A0X =C2=A0X =C2=A0X =C2=A0X =C2=A0X =C2=A0X 15 16 17 18 19=

=C2=A0 =C2=A0cwnd: =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A020 20 10 10 10
=C2=A0 =C2=A0pipe: =C2=
=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A019 19 =C2=A04 10 10
=C2=A0 =C2=A0sent: =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 N =C2=A0=
N 6R =C2=A0R =C2=A0R

=C2=A0
Thanks,
--
Yoshi




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