Re: [PCN] Concensus questions from Thursday's PCN meeting

"Georgios Karagiannis" <karagian@cs.utwente.nl> Wed, 19 March 2008 12:37 UTC

Return-Path: <pcn-bounces@ietf.org>
X-Original-To: ietfarch-pcn-archive@core3.amsl.com
Delivered-To: ietfarch-pcn-archive@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 84D8528C3A7; Wed, 19 Mar 2008 05:37:46 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -100.309
X-Spam-Level:
X-Spam-Status: No, score=-100.309 tagged_above=-999 required=5 tests=[AWL=0.128, BAYES_00=-2.599, FH_RELAY_NODNS=1.451, HELO_MISMATCH_ORG=0.611, RDNS_NONE=0.1, USER_IN_WHITELIST=-100]
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 fDAWz4w1B45X; Wed, 19 Mar 2008 05:37:42 -0700 (PDT)
Received: from core3.amsl.com (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 9603F28C0E3; Wed, 19 Mar 2008 05:37:41 -0700 (PDT)
X-Original-To: pcn@core3.amsl.com
Delivered-To: pcn@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id BF7CA3A6BD2 for <pcn@core3.amsl.com>; Wed, 19 Mar 2008 05:37:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
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 pyI64qVONXdW for <pcn@core3.amsl.com>; Wed, 19 Mar 2008 05:37:39 -0700 (PDT)
Received: from rotterdam.ewi.utwente.nl (rotterdam.ewi.utwente.nl [130.89.10.5]) by core3.amsl.com (Postfix) with ESMTP id 5ED8928C0E3 for <pcn@ietf.org>; Wed, 19 Mar 2008 05:37:39 -0700 (PDT)
Received: from ewi977 (ewi977.ewi.utwente.nl [130.89.12.129]) by rotterdam.ewi.utwente.nl (8.13.6/8.13.6) with ESMTP id m2JCZIgB020265; Wed, 19 Mar 2008 13:35:21 +0100 (MET)
From: Georgios Karagiannis <karagian@cs.utwente.nl>
To: "'Geib, Ruediger'" <Ruediger.Geib@t-systems.com>
References: <BABC859E6D0B9A4D8448CC7F41CD2B0706181835@xmb-rtp-203.amer.cisco.com><RrmbUrJK.1205679770.1867150.karagian@ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF641B0@S4DE8PSAANK.mitte.t-com.de><000001c88809$b2e73840$810c5982@dynamic.ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF6423C@S4DE8PSAANK.mitte.t-com.de><001301c88816$114dab60$810c5982@dynamic.ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF644B1@S4DE8PSAANK.mitte.t-com.de><000001c88835$998bcf60$810c5982@dynamic.ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF6451A@S4DE8PSAANK.mitte.t-com.de><000601c8883b$e3828950$810c5982@dynamic.ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF64580@S4DE8PSAANK.mitte.t-com.de><000901c88844$f35c1130$810c5982@dynamic.ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF645A3@S4DE8PSAANK.mitte.t-com.de><000a01c8884d$081c9790$810c5982@dynamic.ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF64645@S4DE8PSAANK.mitte.t-com.de><1205849919.9521.7.camel@neutrino> <1B6169C658325341A3B8! ! ! 066E23919E1CF64B8 A@S4DE8PSAANK.mitte.t-com.de> <002901c889b5$ad4671a0$810c5982@dynamic.ewi.utwente.nl> <1B6169C658325341A3B8066E23919E1CF64C3B@S4DE8PSAANK.mitte.t-com.de>
Date: Wed, 19 Mar 2008 13:35:13 +0100
Message-ID: <003501c889bd$b07549c0$810c5982@dynamic.ewi.utwente.nl>
MIME-Version: 1.0
X-Mailer: Microsoft Office Outlook 11
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198
In-Reply-To: <1B6169C658325341A3B8066E23919E1CF64C3B@S4DE8PSAANK.mitte.t-com.de>
Thread-Index: AciJAvohbA2GphQvQLWjFvOYYSGt+QAo6JrgAAOauuAAAN9DsAABQa1g
X-Scanned-By: MIMEDefang 2.52 on 130.89.10.5
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0rc3 (rotterdam.ewi.utwente.nl [130.89.10.5]); Wed, 19 Mar 2008 13:35:21 +0100 (MET)
Cc: pcn@ietf.org
Subject: Re: [PCN] Concensus questions from Thursday's PCN meeting
X-BeenThere: pcn@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: PCN WG list <pcn.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/pcn>, <mailto:pcn-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/pipermail/pcn>
List-Post: <mailto:pcn@ietf.org>
List-Help: <mailto:pcn-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/pcn>, <mailto:pcn-request@ietf.org?subject=subscribe>
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Sender: pcn-bounces@ietf.org
Errors-To: pcn-bounces@ietf.org

 Hi Ruediger

It is not a new solution! What I describe are problems that are in my
opinion occuring when 
the PCN domain uses ECMP routing, AND when a catastrophic event occurs AND
when marked 
packets are preferentially dropped.
The only thing that I am trying to say, is PLEASE DO NOT mandate the
preferentially 
dropping of  marked packets, such that we can avoid such difficult and nasty
problems.

I am not proposing here another solution.


Best regards,
Georgios 

> -----Original Message-----
> From: Geib, Ruediger [mailto:Ruediger.Geib@t-systems.com] 
> Sent: woensdag 19 maart 2008 13:06
> To: karagian@cs.utwente.nl
> Cc: pcn@ietf.org
> Subject: RE: [PCN] Concensus questions from Thursday's PCN meeting
> 
> Hi Georgios,
> 
> with how many operator representatives involved into backbone 
> traffic engineering including activation of ECMP did you talk 
> prior to proposing your solution on this mailing list?  
> 
> Regards,
> 
> Rudiger
> 
> 
> | -----Original Message-----
> | From: Georgios Karagiannis [mailto:karagian@cs.utwente.nl]
> | Sent: Wednesday, March 19, 2008 12:38 PM
> | To: Geib, Rüdiger; steven.blake@ericsson.com
> | Cc: pcn@ietf.org
> | Subject: RE: [PCN] Concensus questions from Thursday's PCN meeting
> | 
> | Hi Rudeiger
> | 
> | What I am proposing is how to achieve a robust/stable PCN operation 
> | when the PCN domain uses ECMP routing and when a catastrophic event 
> | occurs.
> | 
> | Best regards,
> | Georgios
> | 
> | 
> | 
> |  
> | 
> | > -----Original Message-----
> | > From: pcn-bounces@ietf.org [mailto:pcn-bounces@ietf.org] On
> | Behalf Of
> | > Geib, Ruediger
> | > Sent: woensdag 19 maart 2008 11:37
> | > To: steven.blake@ericsson.com
> | > Cc: pcn@ietf.org
> | > Subject: Re: [PCN] Concensus questions from Thursday's PCN meeting
> | > 
> | > Steven,
> | > 
> | > what Georgios is proposing is to optimise PCN so that it works 
> | > properly if a catastrophic event coincides with a misconfigured 
> | > router.
> | > 
> | > If this is the main or even an important task of PCN, then
> | I waste my
> | > time here.
> | > 
> | > The salary I obtain monthly depends on my companies
> | backbone network
> | > providing good service to customers under regular operational 
> | > conditions (which cover planned outages and expectable
> | failures). The
> | > telephony or streaming services offered to our customers should 
> | > experience a minimised network impact on the Quality of 
> Experience 
> | > perceived by the consumers under regular operational
> | conditions. This
> | > includes the creation of a "Network Busy Indication", which
> | however is
> | > a rare event. So my position on what PCN should be
> | optimised for is to
> | > create this "network busy indication" for regular operational 
> | > conditions, reliably and only if it is required.
> | > This should be done with the least possible complexity
> | (like the least
> | > possible flow awareness, the least codepoint consumption, simple 
> | > queuing/policing and measurement functions, utmost re-use
> | of allready
> | > implemented features).
> | > 
> | > To clarify what I mean by a rare event: a well engineered 
> backbone 
> | > creating a PCN network busy indication either during a 
> main traffic 
> | > hour or after a re-routing event. During ISDN times, engineering 
> | > resulted in what Americans called 5ESS switches, aiming on
> | a network
> | > busy indication probability of (100 - 99,999%, the 5 
> nines). We may 
> | > see that a bit more relaxed for IP networks, but I don't 
> think the 
> | > customers of my company should experience the consequences of PCN 
> | > behaviour more often than in (100 - 99,x)%.
> | > 
> | > I don't look at PCN as a replacement of network 
> engineering, it is 
> | > rather an add on to guarantee service quality of admitted 
> users by 
> | > stopping admission of new traffic once engineering reaches
> | its limits. 
> | > Under regular operational conditions.
> | > 
> | > If someone now answers to this mail: uhh, just that - easy!
> | > Then lets move this easy thing to WGLC. Now. I can't see that.
> | > 
> | > If the PCN WG indeed has completely different aims, then
> | I'm sorry for
> | > bothering you with my mails (but I wonder whether I'm the
> | one having
> | > gotten things wrong).
> | > 
> | > By the way, I'm happy with the progress visible in the
> | questions you /
> | > the WG has formulated. That looks like a constructive approach.
> | > 
> | > Regards,
> | > 
> | > Rudiger
> | > 
> | > 
> | > 
> | > | -----Original Message-----
> | > | From: Steven Blake [mailto:steven.blake@ericsson.com]
> | > | Sent: Tuesday, March 18, 2008 3:19 PM
> | > | To: Geib, Rüdiger
> | > | Cc: pcn@ietf.org
> | > | Subject: Re: [PCN] Concensus questions from Thursday's 
> PCN meeting
> | > | 
> | > | On Tue, 2008-03-18 at 08:29 +0100, Geib, Ruediger wrote:
> | > | 
> | > | > Hi Georgios,
> | > | > 
> | > | > in the situation you describe, packet losses occur. This
> | > | will result
> | > | > in bad press, as the customers using PCN based services
> | > | were promised
> | > | > another type of service.
> | > | > 
> | > | > In this situation it doesn't matter whether or not ECMP
> | > is deployed
> | > | > and it also doesn't matter whether termination is fair or
> | > not. The
> | > | > important event is: packet losses occur (in one of your
> | examples
> | > | > several routers drop packets). The drops are the only
> | > | relevant issue.
> | > | > Whether service resumes after 5 seconds due to extremly well 
> | > | > engineered termination or after 10 seconds after a
> | > | sufficient number
> | > | > of customers hang up is not important.
> | > | > I can't recall having read anytime in the news "Major
> | > | network outage -
> | > | > but termination was fair." I can only recall having seen
> | > the first
> | > | > part.
> | > | > 
> | > | > I'm sure you're happy in adapting your example, as you
> | do all the
> | > | > time. I'm having work to do, but maybe someone else is
> | > | interested in
> | > | > continuing discusion. I think, I've made my point.
> | > | 
> | > | Ruediger,
> | > | 
> | > | If I follow this comment to its logical conclusion, then PCN is 
> | > | superfluous in this network.  Is that what you are 
> trying to say?
> | > | 
> | > | 
> | > | Regards,
> | > | 
> | > | =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> | > | Steven Blake                <steven.blake@ericsson.com>
> | > | Ericsson/Redback Networks               +1 919-472-9913
> | > | 
> | > | 
> | > _______________________________________________
> | > PCN mailing list
> | > PCN@ietf.org
> | > https://www.ietf.org/mailman/listinfo/pcn
> | > 
> | 
> | 
> | 
> 


_______________________________________________
PCN mailing list
PCN@ietf.org
https://www.ietf.org/mailman/listinfo/pcn