Re: [ledbat] list of reasons for needing multiple TCP connections
Reinaldo Penno <rpenno@juniper.net> Mon, 24 November 2008 23:59 UTC
Return-Path: <ledbat-bounces@ietf.org>
X-Original-To: tana-archive@ietf.org
Delivered-To: ietfarch-tana-archive@core3.amsl.com
Received: from [127.0.0.1] (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id B296D3A6B03; Mon, 24 Nov 2008 15:59:23 -0800 (PST)
X-Original-To: ledbat@core3.amsl.com
Delivered-To: ledbat@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 0BC4E3A6B03 for <ledbat@core3.amsl.com>; Mon, 24 Nov 2008 15:59:23 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.901
X-Spam-Level:
X-Spam-Status: No, score=-5.901 tagged_above=-999 required=5 tests=[AWL=0.699, BAYES_00=-2.599, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hUKmsCKXXSEh for <ledbat@core3.amsl.com>; Mon, 24 Nov 2008 15:59:21 -0800 (PST)
Received: from exprod7og111.obsmtp.com (exprod7og111.obsmtp.com [64.18.2.175]) by core3.amsl.com (Postfix) with ESMTP id 96B773A6A96 for <ledbat@ietf.org>; Mon, 24 Nov 2008 15:59:21 -0800 (PST)
Received: from source ([66.129.224.36]) (using TLSv1) by exprod7ob111.postini.com ([64.18.6.12]) with SMTP ID DSNKSSs/1Pg8qK2+a4iJIovrVH++HB/rWLoo@postini.com; Mon, 24 Nov 2008 15:59:19 PST
Received: from p-emfe01-sac.jnpr.net (66.129.254.72) by P-EMHUB01-HQ.jnpr.net (172.24.192.35) with Microsoft SMTP Server id 8.1.311.2; Mon, 24 Nov 2008 15:55:32 -0800
Received: from p-emsmtp03.jnpr.net ([66.129.254.54]) by p-emfe01-sac.jnpr.net with Microsoft SMTPSVC(6.0.3790.3959); Mon, 24 Nov 2008 15:55:32 -0800
Received: from emailwf1.jnpr.net ([10.10.2.33]) by p-emsmtp03.jnpr.net with Microsoft SMTPSVC(6.0.3790.3959); Mon, 24 Nov 2008 15:55:32 -0800
Received: from proton.jnpr.net ([10.10.2.37]) by emailwf1.jnpr.net with Microsoft SMTPSVC(6.0.3790.1830); Mon, 24 Nov 2008 18:55:31 -0500
Received: from 172.23.1.75 ([172.23.1.75]) by proton.jnpr.net ([10.10.2.37]) with Microsoft Exchange Server HTTP-DAV ; Mon, 24 Nov 2008 23:55:30 +0000
User-Agent: Microsoft-Entourage/12.14.0.081024
Date: Mon, 24 Nov 2008 15:55:17 -0800
From: Reinaldo Penno <rpenno@juniper.net>
To: Stanislav Shalunov <shalunov@shlang.com>, "Andrew G. Malis" <agmalis@gmail.com>
Message-ID: <C5507EE5.16A89%rpenno@juniper.net>
Thread-Topic: [ledbat] list of reasons for needing multiple TCP connections
Thread-Index: AclOkBmw5uhpWMyG5EqWK9p9i6ZyOA==
In-Reply-To: <DC2CEB0C-4C70-42CD-8ADE-AFF4E45B1915@shlang.com>
MIME-Version: 1.0
X-OriginalArrivalTime: 24 Nov 2008 23:55:31.0310 (UTC) FILETIME=[2237A8E0:01C94E90]
Cc: ledbat@ietf.org
Subject: Re: [ledbat] list of reasons for needing multiple TCP connections
X-BeenThere: ledbat@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Mailing list of the LEDBAT WG <ledbat.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/ledbat>, <mailto:ledbat-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/pipermail/ledbat>
List-Post: <mailto:ledbat@ietf.org>
List-Help: <mailto:ledbat-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ledbat>, <mailto:ledbat-request@ietf.org?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: ledbat-bounces@ietf.org
Errors-To: ledbat-bounces@ietf.org
Hello Stas, On 11/24/08 3:28 PM, "Stanislav Shalunov" <shalunov@shlang.com> wrote: > We do need to cover the impact on middleboxes in the document -- it's > in the charter. > > Popular applications are made to work with existing middleboxes. > Middleboxes are made to work with existing popular apps which do open > couple hundred of (mostly idle) TCP connections. Home NATs > ("routers") don't generally crash when you run BitTorrent. The > "mostly idle" part doesn't matter for state consumption, naturally. Why not? A middlebox that offers NAT/FW has to keep track of all connections irrespective if they are mostly idle. > > Thousands and tens of thousands of connections (UDP state counts) is > another matter. Making one DNS request per every swarm member you > learn about will overwhelm a few common devices for large enough > swarms. (There are client behavior extensions that use DNS requests > to learn about locations of peers.) In general, scanning-type > behavior is problematic. Interesting, but usually middleboxes age UDP entries very quickly (specially quickly if they have ALGs). So, TCP and UDP have the dealt differently. > > -- Stas > > > On Nov 20, 2008, at 12:06 PM, Andrew G. Malis wrote: > >> As was mentioned in the IAB plenary yesterday, a reason to not use >> multiple TCP connections is the possible exhaustion of middlebox (read >> NAT) resources, such as state memory or port numbers. So if you are >> going to use multiple connections in parallel, you may wish to include >> a method for the user to control that behavior, and a way to detect >> that you're behind a NAT and adapt appropriately. >> >> Cheers, >> Andy >> >> On Thu, Nov 20, 2008 at 1:43 PM, Joe Touch <touch@isi.edu> wrote: >>> -----BEGIN PGP SIGNED MESSAGE----- >>> Hash: SHA1 >>> >>> Responding to the issue of reasons to need multiple connections, here >>> are a few of mine (extended from those listed at the mic). This is >>> not >>> intended to be a complete list, but a reasonable place to start. The >>> general point is that this is NOT always about hogging bandwidth, >>> either >>> intentionally or not. >>> >>> Joe >>> >>> - -------------------------------------- >>> Reasons to use multiple concurrent TCP connections: >>> >>> - - get around head-of-line blocking >>> this was an original reason for web browsers needing them >>> >>> - - demultiplexing >>> related to HOL blocking but not requiring it, >>> this uses TCP connections to demultiplex different >>> streams, because TCP doesn't provide that labeling itself >>> >>> this was a reason for using different connections for FTP >>> data and control, e.g. >>> >>> - - support different stream properties >>> i.e., a single app may want different streams with Nagle >>> enabled and disabled, or with different socket buffer >>> sizes (to limit delay) >>> >>> - - support "CLOSE means EOF" semantics >>> a reason for multiple connections in HTTP 1.0 >>> >>> - - support larger socket buffer sizes >>> esp. without autotuning, but even with, more connections >>> means more socket buffering is available >>> >>> - ------- >>> >>> One I forgot to note: >>> >>> - - different interaction with errors >>> a single connection would keep restarting; >>> multiple connections increases the possibility that >>> one connection doesn't get hit with a short error burst >>> >>> - ---------------------------------------------- >>> -----BEGIN PGP SIGNATURE----- >>> Version: GnuPG v1.4.9 (MingW32) >>> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org >>> >>> iEYEARECAAYFAkklve4ACgkQE5f5cImnZru0gQCfaxwMKa8BPYliwCay9hFGLcD3 >>> HUQAn1zIlOBJRu1u0qbtpNX8ryuur8ZF >>> =YmcT >>> -----END PGP SIGNATURE----- >>> _______________________________________________ >>> ledbat mailing list >>> ledbat@ietf.org >>> https://www.ietf.org/mailman/listinfo/ledbat >>> >> _______________________________________________ >> ledbat mailing list >> ledbat@ietf.org >> https://www.ietf.org/mailman/listinfo/ledbat > > -- > Stanislav Shalunov > > > > _______________________________________________ > ledbat mailing list > ledbat@ietf.org > https://www.ietf.org/mailman/listinfo/ledbat _______________________________________________ ledbat mailing list ledbat@ietf.org https://www.ietf.org/mailman/listinfo/ledbat
- [ledbat] list of reasons for needing multiple TCP… Joe Touch
- Re: [ledbat] list of reasons for needing multiple… Andrew G. Malis
- Re: [ledbat] list of reasons for needing multiple… Joe Touch
- Re: [ledbat] list of reasons for needing multiple… Kartik Chandrayana (karchand)
- Re: [ledbat] list of reasons for needing multiple… Joe Touch
- Re: [ledbat] list of reasons for needing multiple… Kartik Chandrayana (karchand)
- Re: [ledbat] list of reasons for needing multiple… Joe Touch
- Re: [ledbat] list of reasons for needing multiple… lars.eggert
- Re: [ledbat] list of reasons for needing multiple… Caitlin Bestler
- Re: [ledbat] list of reasons for needing multiple… Joe Touch
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski
- Re: [ledbat] list of reasons for needing multiple… Joe Touch
- Re: [ledbat] list of reasons for needing multiple… Caitlin Bestler
- Re: [ledbat] list of reasons for needing multiple… Reinaldo Penno
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski
- Re: [ledbat] list of reasons for needing multiple… Joe Touch
- Re: [ledbat] list of reasons for needing multiple… Bryan Ford
- Re: [ledbat] list of reasons for needing multiple… Michael Welzl
- Re: [ledbat] list of reasons for needing multiple… Stanislav Shalunov
- Re: [ledbat] list of reasons for needing multiple… Stanislav Shalunov
- Re: [ledbat] list of reasons for needing multiple… Stanislav Shalunov
- Re: [ledbat] list of reasons for needing multiple… Reinaldo Penno
- Re: [ledbat] list of reasons for needing multiple… Stanislav Shalunov
- Re: [ledbat] list of reasons for needing multiple… Murari Sridharan
- Re: [ledbat] list of reasons for needing multiple… Reinaldo Penno
- Re: [ledbat] list of reasons for needing multiple… Stanislav Shalunov
- Re: [ledbat] list of reasons for needing multiple… Murari Sridharan
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski
- Re: [ledbat] list of reasons for needing multiple… Lars Eggert
- Re: [ledbat] list of reasons for needing multiple… Richard Bennett
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski
- Re: [ledbat] list of reasons for needing multiple… Richard Bennett
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski
- Re: [ledbat] list of reasons for needing multiple… Richard Bennett
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski
- Re: [ledbat] list of reasons for needing multiple… Richard Bennett
- Re: [ledbat] list of reasons for needing multiple… Nicholas Weaver
- Re: [ledbat] list of reasons for needing multiple… Reinaldo Penno
- Re: [ledbat] list of reasons for needing multiple… Eric Spaeth
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski
- Re: [ledbat] list of reasons for needing multiple… Robb Topolski