From nobody Mon Feb 15 07:48:36 2021 Return-Path: X-Original-To: quic@ietfa.amsl.com Delivered-To: quic@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C0FDE3A0CB8 for ; Mon, 15 Feb 2021 07:48:34 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: 0.053 X-Spam-Level: X-Spam-Status: No, score=0.053 tagged_above=-999 required=5 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, HTML_MESSAGE=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 tDWO2gJ3B9K9 for ; Mon, 15 Feb 2021 07:48:33 -0800 (PST) Received: from mail-yb1-xb36.google.com (mail-yb1-xb36.google.com [IPv6:2607:f8b0:4864:20::b36]) (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 1A50B3A0CB7 for ; Mon, 15 Feb 2021 07:48:33 -0800 (PST) Received: by mail-yb1-xb36.google.com with SMTP id k4so7581884ybp.6 for ; Mon, 15 Feb 2021 07:48:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=RG8vRLVPauxsMxbIW/o6TAB9Hb3OcetdoYUrIxzXPds=; b=FCW2koerjLtxuNyeGChYvBSyPNhxgHy7MaZINTN2Gh7QrNqDAJDruawzLIrIIti1ek fD+awz986cuwyaSKXBf7wctzBbGXlSMSEwZhJ5n4FyvUSCV4cbnSQcyljutjyNae4xec gq4YcLc2I4GgSgs73kh3QIzXKPmtzRW9+3bqQOggJmAzsCfy9I32SnHGoZFnCzNaZtT3 W7wwdVyaQAJ2T/jNudyeQ5ekP3K10dhA+t4jncA1ysVRgWHK0EXlC4KDrau/6XxD/L+c M/sW10DcNhmLAJgERZQ7Jl/hGI0puwe4Ty8LLQjxcUwAogdkiWr8rYmxGVflZPIYxXdw fRcQ== 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:reply-to :from:date:message-id:subject:to:cc; bh=RG8vRLVPauxsMxbIW/o6TAB9Hb3OcetdoYUrIxzXPds=; b=sh+5Xb4n9S+oiOt/wyK/JL0CtNFjanAlgXk7gVfmzNDPl8kyEMRzcshSj48p2pN685 NNyxkKp45IJc0VGGN7YzV5HCY3Sx7pSEyeiikyICZ/0yTG8csMyy4bpVu14s/zi6+LAC gOwSLgTk/ouWUGgikRv8K9Njze8TmQw+VbPtGda/rDZCAALWFtSF9crFgY/1p0zbXtF8 6GEInN7WP6ESuGOfDrGCw6DT7JckkXZMdTNtlxj8s2h2Oc+IF9YK1SBGyGWH/+jd7fZH VKeJxjEkmA6JnWN4MlITxYK9VRwjSAt1mJyNZE3rawDkjt9imbraSXccv6fMvuddSrj0 Sbpg== X-Gm-Message-State: AOAM533h3qdQF3p+5NPt1ddpEUEN9wOefU9qOqjDg7lpalK+qXr3ddxa 2Il5p9i/AT0weJMkxywwlRXQDwLcAsOPNO49uvVMSQ0E7i0= X-Google-Smtp-Source: ABdhPJxv9DquAqdlLN4fKkYr9P0SpG1EPJr7f2ZjvbdqCX0Cx6F2FOjbeL2XmEii013E24zcgPBPxBs6ECwgm45RF08= X-Received: by 2002:a25:cbd5:: with SMTP id b204mr22000301ybg.411.1613404112311; Mon, 15 Feb 2021 07:48:32 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Reply-To: sarikaya@ieee.org From: Behcet Sarikaya Date: Mon, 15 Feb 2021 09:48:21 -0600 Message-ID: Subject: Re: Options for QUIC Multipath To: Christian Huitema Cc: IETF QUIC WG Content-Type: multipart/alternative; boundary="000000000000fe58f105bb61ea26" Archived-At: X-BeenThere: quic@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Main mailing list of the IETF QUIC working group List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Feb 2021 15:48:35 -0000 --000000000000fe58f105bb61ea26 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, Feb 14, 2021 at 4:23 PM Christian Huitema wrote: > I authored two drafts proposing two different solutions for Multipath > QUIC: QUIC Multipath Negotiation Option ( > https://datatracker.ietf.org/doc/draft-huitema-quic-mpath-option/); and, > in collaboration with colleagues at Ali Baba, Multipath Extension for QUI= C ( > https://datatracker.ietf.org/doc/draft-liu-multipath-quic/). Apart from > some details that could easily be aligned, the main difference is that th= e > =E2=80=9Cnegotiation option=E2=80=9D maintains the property of QUIC Trans= port > to have a > single packet number space for all application packets while the =E2=80= =9Cmultipath > extension for QUIC=E2=80=9D specifies that there will be a specific packe= t number > space for each path. I have now implemented both options in Picoquic. Thi= s > blog describes what I learned: > https://huitema.wordpress.com/2021/02/14/how-many-packet-number-spaces-fo= r-quic-multipath/ > . > > To summarize, I believe now that both options work. The simple option > requires some additional work for managing acknowledgement, but the > multiple number space option adds a lot more complexity (41 new code > branches compared to only 6), and will require a lot more testing because > it also change the processing of the "single path" scenarios. The multipl= e > number space option also prevents the use of zero-length connection IDs, > and thus causes additional overhead in some important deployment scenario= s. > So, yes, both options work, but the simpler option provides simpler code > and also less overhead. > Great! I thought it was a given. Thanks for your hard work Christian. Behcet > In any case, I hope that this exercise will inform our efforts to > standardize multipath support in QUIC. > > -- Christian Huitema > > > --000000000000fe58f105bb61ea26 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


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On Sun, Feb 14, 2021 at 4:23 PM Chris= tian Huitema <huitema@huitema.net= > wrote:
=20 =20 =20

I authored two drafts proposing two different solutions for Multipath QUIC: QUIC Multipath Negotiation Option (https://datatracker.ietf.org/doc/draft-huitema-= quic-mpath-option/); and, in collaboration with colleagues at Ali Baba, Multipath Extension for QUIC (https://datatracker.ietf.org/doc/draft-liu-multipath-q= uic/). Apart from some details that could easily be aligned, the main difference is that the =E2=80=9Cnegotiation option=E2=80=9D maintains= the property of QUIC Transport to have a single packet number space for all application packets while the =E2=80=9Cmultipath extension for QUIC= =E2=80=9D specifies that there will be a specific packet number space for each path. I have now implemented both options in Picoquic. This blog describes what I learned: https://huitema.wordpress.com= /2021/02/14/how-many-packet-number-spaces-for-quic-multipath/.

To summarize, I believe now that both options work. The simple option requires some additional work for managing acknowledgement, but the multiple number space option adds a lot more complexity (41 new code branches compared to only 6), and will require a lot more testing because it also change the processing of the "singl= e path" scenarios. The multiple number space option also prevents the use of zero-length connection IDs, and thus causes additional overhead in some important deployment scenarios. So, yes, both options work, but the simpler option provides simpler code and also less overhead.



Great!=C2=A0
I thought it was a given.

Thanks for your hard work Christian.

Behcet= =C2=A0

In any case, I hope that this exercise will inform our efforts to standardize multipath support in QUIC.

-- Christian Huitema


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