From owner-freebsd-net@freebsd.org Tue Jul 18 17:58:30 2017 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E8586D9BC38 for ; Tue, 18 Jul 2017 17:58:30 +0000 (UTC) (envelope-from krishnavijay@mnnit.ac.in) Received: from mail-qt0-x22f.google.com (mail-qt0-x22f.google.com [IPv6:2607:f8b0:400d:c0d::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id AE6967C69B for ; Tue, 18 Jul 2017 17:58:29 +0000 (UTC) (envelope-from krishnavijay@mnnit.ac.in) Received: by mail-qt0-x22f.google.com with SMTP id n42so22394860qtn.0 for ; Tue, 18 Jul 2017 10:58:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mnnit-ac-in.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to; bh=xNbv3dYLp9BWEkAw9WO/JVoYwVbkJevgPRbIDNRKr9k=; b=Mt/DBlgngx7Iy0NrLo/rUHkoF2RB0doyo+RDORWhbb2ZDFZl8+RxR7CHevO3nv3ha+ 8c/EfI9HwUJHmzGKRTYv17y0Py2nrTq20f3ZnTZqjfRHUNruF7MshnqSgZHa2m0BgaY/ cfghuOw45R7l+NSHPkWI8X/dqmNM4tBc6s7jQI7BEkr1doSX9RxS22Hw28/MMiHx78oq Uh+c80lyW2uBPzHI/NbEuM/iYHT1gd9nIoxWGMQgTTxs9RAKvMkpNYIc4lElU+2Bg8vA 3Ygzeg/R0K8Fj57W1wMXfLawJJHzdgkKnoXzCCNVqtXihuZ0D9yM3H4sypjwypyqhzCt Wamw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=xNbv3dYLp9BWEkAw9WO/JVoYwVbkJevgPRbIDNRKr9k=; b=J9Q/LPMlFNUKEuMKknqd4CwpLG29BjKEkQl1UusnosWqZDJ0E/WbEe5r4ihc2QhW8D IHe3goDixRqbV3vmKclgKUddUV7WSVov98Ft63hFfsnwm8+JXwHMzjneURgrZORMViQF noHT5uKnMZv5RbFTGRdj9zGGOwGcqfCiVj8F0SSzO/D0jUS8ZA7+Wavq+eku52m+hqv/ UaZQxRjmGbMvdX6sHt8fjc72mn43smcKS+sKrsV0IqSeJMiL8YjOaY7LVBEMOVLxbBZX rchDr1H0gz+6LQcrTHWh78gWjzXUTJrRWVhUYwf4oD+4fk+chkKjOktOYIPLUe49ViTt 3fZA== X-Gm-Message-State: AIVw111JmUu06ypsLic1gKWCTklOwkpv/q1e7GW9khwhIoiizHouyhJd PsUuxOOx8/KqpmOxmH5tCjAbrjD5nxjdONw= X-Received: by 10.200.36.205 with SMTP id t13mr3588667qtt.147.1500400707987; Tue, 18 Jul 2017 10:58:27 -0700 (PDT) MIME-Version: 1.0 Received: by 10.12.180.19 with HTTP; Tue, 18 Jul 2017 10:58:27 -0700 (PDT) From: KVK Singh Date: Tue, 18 Jul 2017 23:28:27 +0530 Message-ID: Subject: TCP Zero Window Advertisement. To: freebsd-net@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Jul 2017 17:58:31 -0000 Hi, By going through the Zero Window advertisement concept What I found is that if sender has transmitted packet 2,3,4,5,6,7 i.e packet from 2-7 total 6 packets in flight then By chance if sender received a Zero Window Advertisement (ZWA) for segment 4 then it does not enters in probe mode/ persistent state. However if it receive ZWA for 7 i.e last packet in flight then it enters in Probe mode/ persistent state and it starts probing for window update. Is that the behavior is correct Because as going through the paper and RFC I find that any segment can be acked with ZWA and sender will enter in persist mode once it receive the ZWA. Please resolve my query. Thanks and regards.