Re: [multipathtcp] Timestamp option for Multipath TCP

Olivier Bonaventure <> Wed, 29 March 2017 13:06 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 2DA261294F0 for <>; Wed, 29 Mar 2017 06:06:10 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -4.321
X-Spam-Status: No, score=-4.321 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id GHtDeYrOTLC5 for <>; Wed, 29 Mar 2017 06:06:08 -0700 (PDT)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id C990A1294DB for <>; Wed, 29 Mar 2017 06:06:07 -0700 (PDT)
Received: from mbpobo.local (unknown []) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: by (Postfix) with ESMTPSA id D5F8A67D9F3; Wed, 29 Mar 2017 15:05:59 +0200 (CEST)
DKIM-Filter: OpenDKIM Filter v2.9.2 D5F8A67D9F3
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple;; s=selucl; t=1490792760; bh=RPVzERDWBp22+/Fk+QOpt01YEyvraPRQsgVbMy4xnpk=; h=Reply-To:Subject:References:To:Cc:From:Date:In-Reply-To; b=gNr7qyPAwFgEoz18Rn/laemBkoMqVOJx9+RwoYKX8zU9ecWbCSca09Do8OHfuSa6S qPtz9kpQf9EX+/s5+RUlO5gZt6f+k1mgXM1kq92cCrriEudUBN4Mhd30Xre4P/IMFD 3NpZRSy+CVEb7qLz1Cty0oLmdbyIGBlQCzBIJ5uA=
X-Virus-Status: Clean
X-Virus-Scanned: clamav-milter 0.99.2 at smtp-1
References: <> <>
To: Yoshifumi Nishida <>
Cc: multipathtcp <>
From: Olivier Bonaventure <>
Message-ID: <>
Date: Wed, 29 Mar 2017 15:05:58 +0200
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.8.0
MIME-Version: 1.0
In-Reply-To: <>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Sgsi-Spamcheck: SASL authenticated,
X-SGSI-MailScanner-ID: D5F8A67D9F3.A7053
X-SGSI-MailScanner: Found to be clean
X-SGSI-Spam-Status: No
Archived-At: <>
Subject: Re: [multipathtcp] Timestamp option for Multipath TCP
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Multi-path extensions for TCP <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Wed, 29 Mar 2017 13:06:10 -0000

> I personally prefer 1, but I might prefer some generic framework as I am
> guessing there will be other cases that we don't want timestamps for PAWS.
> BTW, are we sure that DSN option can provide protections against PAWS?
> We cannot guarantee DSN option appears on all segments..

If there is a valid DSS option, either DSN mapping or DSN ack, then the 
segment cannot be a replay of an old segment. If we use long mappings, 
then there are two different situations :

- long mapping but TSO copies the DSS option inside each packet
- long mapping and no TSO

In the second case, we need to ensure that each packet contains some 
information that allows to support PAWS. DSS and timestamp would work