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Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH
Flow Aware Networking
Router model
lead by prof. dr hab. inż. Andrzej Jajszczyk
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH2/23 Jakub Palider
Outline
Transmission requirements
QoS
Existing architectures (IntServ, DiffServ)
FAN mechanisms
Cross-protection: MBAC
Conclusion
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH3/23 Jakub Palider
Outline
Transmission requirements
QoS
Existing architectures (IntServ, DiffServ)
FAN mechanisms
Cross-protection: MBAC
Conclusion
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH4/23 Jakub Palider
Current network quality requirements
Nowadays networks are expected to support a variety of services beyond the best-effort service available today
New applications already rely on the network ability to guarantee such services
High speed packet-switched networks
Applications requiring bandwidth
Applications requiringlow latency
VoIP, tele-conferencing, UMA, on-line gaming,
distance learning
P2P Networks, Large Databases, Large multimedia files,
XBOX Live
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH5/23 Jakub Palider
What is congestion?
Simple definition: congestion occurs when traffic coming into one link exceeds its capacity e.g. motorway
Main reason: lack of bandwidth
– Demand bigger than capacity
– Suddenly changing demands
– Network failures
– Changes in routing
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH6/23 Jakub Palider
Outline
Transmission requirements
QoS
Existing architectures (IntServ, DiffServ)
FAN mechanisms
Cross-protection: MBAC
Conclusion
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH7/23 Jakub Palider
QoS
In streaming traffic type following guarantee an end-user proper:
Packet delay
Mean bit rate
Stream bit rate
Packet loss
Jitter
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH8/23 Jakub Palider
Outline
Transmission requirements
QoS
Existing architectures (IntServ, DiffServ)
FAN mechanisms
Cross-protection: MBAC
Conclusion
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH9/23 Jakub Palider
What are the current QoS solutions?
Already Implemented:
Integrated Services – IntServ, the first model defining whole concept of QoS
Differentiated Services – DiffServ – later conception, opposite (in majority) to IntServ
New Idea:
Flow Aware Networking
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH10/23 Jakub Palider
Traffic conditioning mechanisms
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH11/23 Jakub Palider
IntServMemory load
High
High
Low
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH12/23 Jakub Palider
DiffServMemory load
High
High
Low
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH13/23 Jakub Palider
How does congestion control is implemented in DiffServ?
Network traffic entering a DiffServ domain is subjected to classification and conditioning
AC realized only in edge routers, controlled by Bandwidth Broker
PHB define packet forwarding properties inside domain
QoS Mechanisms
Packet level Admission level
classifier
traffic conditioners
scheduler
AC (admission control)
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH14/23 Jakub Palider
Main differences between IntServ and DiffServ
Bilateral agreementsMultilateral agreementsInter domain deployment
Scalable and robustInformation held in each network node – not scalable
Scalability
Cannot provide low delay and high bandwith guarantee
simultaneously
Per flow - bandwidth and delay guarantee
Quality guarantees
Similar to IP networksSimilar to network switching (e.g. phone calls)
Network management
Based on class usageBased on flow characteristics and QoS requirement
Network accounting
Limited by number of classes of service
Limited by number of flowsClassification of traffic
Per hopEnd to endCoordination for service differentation
DiffServIntServParameter
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH15/23 Jakub Palider
Outline
Transmission requirements
QoS
Existing architectures (IntServ, DiffServ)
FAN mechanisms
Cross-protection: MBAC
Conclusion
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH16/23 Jakub Palider
Features of FAN
No reservation
Classification based on flows
2 flow classes - stream (audio, video, real-time) and elastic (digital documents)
Idea of cross-protect router – accurate relation between admission control and scheduling
“Good enough” performance
Cost effectiveness and accountability $$$
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH17/23 Jakub Palider
What DiffServ congestion control ideas have in common with FAN?
The only common mechanisms are admission control and scheduling, but the admission control is realized in different way
Scheduling algorithms may be implemented in FAN
There are many elementary conceptions common to both architectures – but these are mostly basics of QoS idea
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH18/23 Jakub Palider
Outline
Transmission requirements
QoS
Existing architectures (IntServ, DiffServ)
FAN mechanisms
Cross-protection: MBAC
Conclusion
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH19/23 Jakub Palider
Measurement Based Admission Control (MBAC)
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH20/23 Jakub Palider
Cross-protection in FAN router
Incoming packets Outgoing packets
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH21/23 Jakub Palider
Outline
Transmission requirements
QoS
Existing architectures (IntServ, DiffServ)
FAN mechanisms
Cross-protection: MBAC
Conclusion
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH22/23 Jakub Palider
FAN – pros and cons…
Advantages Disadvantages
Good scalability
Ease of admission control in each network node (MBAC)
Only small amounts of data stored in network node memory
No strict guarantees of network performance
Not implemented yet
Flow Aware Networking
© 2007 Katedra Telekomunikacji AGH23/23 Jakub Palider
Thank you for attention!
to be continued…