[PCN] Termination of flows in small aggregates

[<Ruediger.Geib at telekom.de>]

Hi Phil,

I'm not a staunch supporter of termination. I'm having a question related 
to termination of small aggregates.

Assume 10% excess marked traffic at a particular egress.

- 5 flows for IEA1
- 3 flows for IEA2

Each flow consumes the same bandwidth. 

I don't think that it matters whether decisions are taken at ingress or 
egress. The farther congestion is from an ingress or egress, the lower 
the number of IEAs. That means, that either the ingress or egress may 
control a number of small aggregate IEAs, depending on the location of 
the pre-congested interface.

As far as I understand, there's no way to signal which flows are the most 
burdensome for a pre-congested interface. Maybe the above 8 flows consume
10 times the average bandwidth of any other flow passing the pre-congested 
interface. The egress can't learn about that.

I'm not out for an endemic fairness discussion and I don't want to start 
a re-ECN discussion here. A pragmatic rule then would be "terminate 
one flow"? Or should the reaction be configurable?

I'm not looking for solutions which result in flow awareness at 
pre congested interfaces or centralised systems having an overview.

Regards,

Ruediger



Deutsche Telekom Netzproduktion GmbH 
Zentrum Technik Einführung 
Technik Internet Backbone, TE142-19
Rüdiger Geib
Heinrich Hertz Str. 3-7
64297 Darmstadt
Tel.: 06151/6282747
Fax: 0251/7985109


Deutsche Telekom Netzproduktion GmbH 
Aufsichtsrat: Dr. Steffen Roehn (Vorsitzender) 
Geschäftsführung: Dr. Bruno Jacobfeuerborn (Vorsitzender), Albert Matheis, Klaus Peren 
Handelsregister: Amtsgericht Bonn HRB 14190 
Sitz der Gesellschaft: Bonn 
USt-IdNr.: DE 814645262