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

"Geib, Ruediger" <Ruediger.Geib@t-systems.com> Wed, 19 March 2008 13:42 UTC

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Thread-Topic: [PCN] Concensus questions from Thursday's PCN meeting
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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$810c5982@dynamic.ewi.utwente.nl><1B6169C658325341A3B8066E23919E1CF64645@S4DE8PSAANK.mitte.t-com.de><1205849919.9521.7.camel@neutrino> <1B6169C658325341A3B8! ! ! ! ! 066E23919E1 CF64B8A@S4DE8PSAANK.mitte.t-com.de> <002901c889b5$ad4671a0$810c5982@dynamic.ewi.utwente.nl> <1B6169C658325341A3B8066E23919E1CF64C3B@S4DE8PSAANK.mitte.t-com.de> <003501c889bd$b07549c0$810c5982@dynamic.ewi.utwente.nl> <1B6169C658325341A3B8066E23919E1CF64CCF@S4DE8PSAANK.mitte.t-com.de> <003d01c889c4$1c998e80$810c5982@dynamic.ewi.utwente.nl>
From: "Geib, Ruediger" <Ruediger.Geib@t-systems.com>
To: karagian@cs.utwente.nl
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Subject: Re: [PCN] Concensus questions from Thursday's PCN meeting
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Hi Georgios,

I assume the costs to marginal as compared to the expenditure 
required to avoid these losses. We face tough regulation and 
can't stay in business if we engineer networks for resilience 
during catastrophic outages. These times are gone.

During catastrophic outages, my operational staff will require 
good OAM tools to enable return to bearable operation as soon 
as possible. To me, OAM is the only section in PCN drafts 
I'd like to be addressed to deal with catastrophic outages.

Regards

Rudiger

| -----Original Message-----
| From: Georgios Karagiannis [mailto:karagian@cs.utwente.nl] 
| Sent: Wednesday, March 19, 2008 2:21 PM
| To: Geib, Rüdiger
| Cc: pcn@ietf.org
| Subject: RE: [PCN] Concensus questions from Thursday's PCN meeting
| 
| Hi Ruediger
| 
| I do not know, but when such an event occurs, what are then 
| the costs involved associated with the financial losses and 
| customer losses for an operator of a large network with a 
| huge number of subscribers?
| 
| Best regards,
| Georgios
| 
| 
| 
| > -----Original Message-----
| > From: Geib, Ruediger [mailto:Ruediger.Geib@t-systems.com]
| > Sent: woensdag 19 maart 2008 14:17
| > To: karagian@cs.utwente.nl
| > Cc: pcn@ietf.org
| > Subject: RE: [PCN] Concensus questions from Thursday's PCN meeting
| > 
| > Hi Georgios,
| > 
| > could you give us an estimate of the propability that this problem 
| > occurs? How often within a year?
| > 
| > Regards,
| > 
| > Rudiger
| >  
| > 
| > | -----Original Message-----
| > | From: Georgios Karagiannis [mailto:karagian@cs.utwente.nl]
| > | Sent: Wednesday, March 19, 2008 1:35 PM
| > | To: Geib, Rüdiger
| > | Cc: pcn@ietf.org
| > | Subject: RE: [PCN] Concensus questions from Thursday's PCN meeting
| > | 
| > | 
| > |  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
| > | > | > 
| > | > | 
| > | > | 
| > | > | 
| > | > 
| > | 
| > | 
| > | 
| > 
| 
| 
| 
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