Subject: [PCN] Target reaction time for PCN

From: Tom Taylor <[email-masked]>
Date: Thu, 10 Mar 2011 21:07:54 -0500

OK, folks, I'm the one who invented a target reaction time of 1-3 
seconds for PCN (I think, maybe my memory is playing tricks on me), but 
some people have seemed a bit surprised by this statement in the edge 
behaviour drafts. Do people have other ideas? It would be good to know 
because our timer durations (e.g., measurement period duration, time to 
detect failure) are related to this objective.

Tom Taylor

---

From: Michael Menth <[email-masked]>
Date: Fri, 11 Mar 2011 09:41:26 +0100

Hi Tom and all,

this duration is reasonable. The meter and marker takes 1-2 seconds to 
start marking, in case of light pre-congestion. We have on average a 
measurement delay of the duration of the measurement interval if the CLE 
limit is 0.5, we need a RTT for signalling, and there is probably a 
media delay (time between admission of a flow until the flow sends data) 
that contributes to delayed blocking. Media delay is hard to control and 
I have no empirical data that give a clue how long it takes. Therefore, 
I think it is reasonable to assume a reaction delay for admission 
control with CL is in the range of 1-3 seconds. It is definitely not 
realistic to assume it less than 1 s.

I have not looked at the numbers for CL and flow termination, but I 
guess they are in a similar order of magnitude due to marking delay and 
the relatively complex way to terminate traffic which requires 
additional measurement results from the ingress node.

Regards,

     Michael

Am 11.03.2011 03:07, schrieb Tom Taylor:
> seconds for PCN (I think, maybe my memory is playing tricks on me), 
> but some people have seemed a bit surprised by this statement in the 
> edge behaviour drafts. Do people have other ideas? It would be good to 
> know because our timer durations (e.g., measurement period duration, 
> time to detect failure) are related to this objective.
>
> Tom Taylor
> _______________________________________________
> PCN mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/pcn

-- 
Prof. Dr. habil. Michael Menth
University of Tuebingen
Faculty of Science
Department of Computer Science
Chair of Communication Networks
Sand 13, 72076 Tuebingen, Germany
phone: (+49)-7071/29-70505
fax: (+49)-7071/29-5220
mailto:[email-masked]
http://www-kn.informatik.uni-tuebingen.de