Networking and Quality of Service

Robin Tasker, Daresbury Laboratory, 20 October 2000

In the UK, based on a GRID networking workplan :-

definition and understanding of terms of QoS;

traffic management techniques;

diffserv;

bandwidth broker techniques and capabilities; and

GRID matchmaking

Development Process

Understanding :-theoretical basis of approach etc..

Laboratory testbed for techniques :-develop (or learn from others’) experience in well constrained environments

Wide area testing of techniques :-look for the issues, costs and benefits in the “real world”

Wide area deployment - if appropriate and possible

ESnet JANET

ns2.slac.stanford.edu

evagore.slac.stanford.edu

icfamon.dl.ac.uk

By defaultALL ESnet traffic marked “high” priority

into JANET via NY PoP

Traffic from evagore.slac.stanford.edumarked at “normal” priority into JANET

at the NY PoP

(CAR + WRED)

Low-level traffic management techniquesCongestion Avoidance - CAR and WRED

ESNetHigh Priority

CAR+WREDenabled

Config changes toCAR and WRED

Further configchanges

ESNetNormal Priority

CAR+WREDenabled

Config changes toCAR and WRED

Further configchanges

Abilene JANET

icfamon.dl.ac.uk

By defaultALL Abilene traffic marked “high” priority

into JANET via NY PoP

(CAR + WRED)

Just how relevant are such techniques?

CAR+WREDenabled

Config changes toCAR and WRED

Further configchanges

AbileneHigh Priority

Peeringbandwidth increased

Conclusions

Understanding of theoretical basis of approach is important

Laboratory testbed for techniques either to develop (or to learn from others’) experience in a well constrained environment is important

Wide area testing of techniques looking for the issues, the costs and the benefits in the “real world” is absolutely vital

QoS techniques may be exciting and interesting but do they give best return on investment to meet user requirements?