a preliminary implementation of a content–aware network node
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A PRELIMINARY IMPLEMENTATION OF A CONTENT–AWARE NETWORK NODE
N. Vorniotakis, G. Xilouris, G. Gardikis, N. Zotos, E. Palis, A. Kourtis
!st Workshop on Multimedia-Aware Networking 2011 (WoMAN ‘11)
Contents• Introduction• Scope• Content-Awareness Enablers• Design • Experimental Testbed• Validation and experimental results• Acknowledgments - Conclusions
2 ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Introduction• Multimedia content is anticipated to be increased at least by a
factor of 6 in 2012• Network nodes are currently agnostic to the content they deliver• In order for future network architectures to cope with this
environment – continue to provide fast switching and forwarding at the core – push the intelligence to the edge
• Given the constant evolution in hardware capabilities — in terms of CPU power and memory availability there is the capability to:
Provide new functionalities to the network nodes in order to make the network aware of the content being transferred hence applying specific policies or routing respectively
3 ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Scope • This work presents a preliminary design of a content-aware
network node• Discusses the main concepts and principles governing this design • Presents an preliminary implementation of an algorithm for
identification of multimedia streams over RTP protocol• Validates the proof-of-concept through experimental results
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Content-Awareness Enablers
• Flow awareness– content-awareness should be performed per-flow of network
data– Use of hash tables where every active flow record, is
maintained by the network node• Mechanisms for removal of idle or zombie flows are mandatory in
order to be detected and removed, and free memory – Enables the processing of the minimum required amount of
packets– Resulting
• Smaller processing delays • Better scalability
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Content-Awareness Enablers
• Traffic Classification– Current techniques exploit information taken from OSI Layer 3
to Layer 7– Many techniques combine multilayer information with
application data inspection (DPI) for accurate traffic identification
– Less invasive to privacy methods involve statistical analysis of the flow dynamics
– Methods used to classify traffic at application level include• Exact Matching• Prefix Matching • Heuristics methods• Machine learning based on statistical features
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Design
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• C-A functions were designed to be modular and scalable
• Flow Handling module comprises of • the Packet Capturer
module that captures incoming network packets
• Flow Handler that organizes incoming packets to network flows.
• Routing module comprises of: • Packet Marker and the
Routing Tables Handler
• Content Awareness Module depends on the Heuristics functions to determine the service of each flow using either Deep Packet Inspection (DPI) techniques or Port to Service Mapping for simple services identification
• Policer Module is in charge of applying the desired policies at the respective flows. This module includes also the queue schedulers that are used for traffic control (shaping, differentiation, prioritization)
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Design – Routing Module
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• Routing Module• for every incoming flow, after the content is identified
three main decisions need to be made.• how to police the traffic at the ingress interface• how to route the flow • how to handle (shaping, conditioning,
prioritization) the flow at the egress. • This module exploits functionalities provided by the
Linux OS kernel and User Space utilities (i.e. iptables, traffic control
• Content Mapping Table that contains information on how to police and condition the flows depend- ing on content type
• A number of alternative local RIBs is used that are statically pre-assigned
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Design – RTP dissector
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• Incoming packets are traversing the processing loop, each one is checked to determine whether it belongs to an already established flow
• The actual detection algorithm is much more complex so it can be accurate on most cases since it has more passes and also takes into account RTCP data.
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Design – RTP dissector
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• Incoming packets are traversing the processing loop, each one is checked to determine whether it belongs to an already established flow
• The actual detection algorithm is much more complex so it can be accurate on most cases since it has more passes and also takes into account RTCP data.
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Experimental Test-bed
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• streaming server streams a flow of a video using RTP to the client that is considered to be a high priority service
• traffic generator is used to create a gradually increasing source of background traffic
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Experimental - Cases
• Testing Scenarios– Case1 - content agnostic network– Case2 - traffic classification based
on policies and HTB– Case3 - traffic classification based
on content identification
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Experimental-Results
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Case1
Case2
Case3
• The proof of concept of the content-aware network node is proved
• In case3 the content aware features of the ingress node allow the selection of different path in the network
• The one way delay is not affected by the operation of the C-A algorithm
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
Acknowledgments
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This work has been supported by the European Research Project FP7 “MediA Ecosystem Deployment Through Ubiquitous Content-Aware Network
Environments” ICT-ALICANTE Project No. 2010-2013. http://www.ict-alicante.eu
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
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Thank you for your attention
Questions ?
Contact informationNikolaos Vorniotakis (nkvorn@iit.demorkritos.gr)
George Xilouris (xilouris@iit.demokritos.gr)
ICME 2011 Conference, WOMAN Workshop July 11 2011, Barcelona
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