Opportunities and Research
Challenges of Hybrid Software
Defined Networks
ACM SIGCOMM Computer Communication Review table of
contents archive Volume 44 Issue 2, April 2014
Authors: Stefano Vissicchio and Olivier Bonaventure from
Université catholique de Louvain, Louvain-la-Neuve,
BelgiumLaurent Vanbever from Princeton University,
Princeton, NJ, USA
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Outline
• Why use hybrid SDN (hSDN)?
• Type of hSDNs
•
•
•
•
Topology based hSDN (TB hSDN)
Service based hSDN (SB hSDN)
Class based hSDN ( CB hSDN)
Integrated hSDN
• Tradeoff analysis
• Conclusion
• Future work
• Reference
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Why use hybrid SDN (hSDN)?
• SDN has a lot of advantages.
• Simplify management
• Spur innovation
• Improve network flexibility
• However…
• Full SDN require huge number of initial deployment costs.
• Operator need to dismiss expensive commercial off-the-shelf network (CN)
device to enable full SDN deployment.
• Training cost.
• Production-level SDN controller still seem hard to realize. They
need:
• Security policy enforcement
• High availability
• Lowest possible delay
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Why use hybrid SDNs (hSDN)? – cont’d
• However…
• The full SDN architecture may lack
• Reliability
• Robustness
• Scalability
• Hybrid SDN
• If we need centralized control and we also want scalability in
our network, why do not we use hybrid SDN?
• If we do not have enough money to upgrade all device to
support SDN, why do not we use hybrid SDN?
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Topology based hSDN (TB hSDN)
• The network is partitioned in
disjoint zones.
• In SDN (resp. CN ) zones, all
services are provided by SDN
(resp. CN).
• Transition strategy:
• CN manage the back-bone
traffic
• SDN control non-critical traffic
• Why?
• It eases the introduction of
new mechanisms to exchange
information between SDN
zones and CN zone.
Forwarding Information Base (FIB)
of SDN
FIB of CN
Physical link
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Service based hSDNs (SB hSDNs)
• CN and SDN provide different
service.
• Transition strategy:
• SDN progressively handles more
and more services.
• Why?
• Operators may be willing to keep
existed CN protocols instead of
relying on new software to be
integrated in the SDN controllers.
• SDN is used for services that CN
solutions cannot satisfactorily
provide.
Forwarding Information Base (FIB)
of SDN
FIB of CN
Physical link
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Class based hSDNs ( CB hSDNs)
• All node can be controlled by CN
and SDN.
• All node provide all network
service.
• Transition strategy:
• All node must support both CN and
SDN protocols.
• This model may be adopted as a
long-term design.
• Why?
• CN can work as a backup when SDN
control plane crashes.
Forwarding Information Base (FIB)
of SDN
FIB of CN
Physical link
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Integrated hSDNs
• SDN is responsible for all network
services, and uses CN protocols as
an interface to devices’ FIBs.
• Transition strategy:
• Step1: Move the control plane from
CN to SDN
• Step2: Adding SDN devices and
updating the SDN controller.
• Why?
• SDN is easy to offloaded when SDN
is die.
Forwarding Information Base (FIB)
of SDN
FIB of CN
Physical link
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Tradeoff analysis
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Conclusion and future works.
• Explore the hSDN models.
• Some challenges of hSDN:
• The cross-paradigm techniques need to be studied.
• A control plane redesign would be needed to allow effective
cooperation between SDN controllers and CN controllers.
• The added complexity of combined heterogeneous networks may
hamper the development of SDN in a hSDN.
• Personal opinions:
• It provides some useful reference for me.
• My implementation belongs to SB hSDNs. I can use its example to
convince others that my system is useful.
• Their design suggestions can be better.
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Reference
• Software-Defined Networking (SDN) Definition
[https://www.opennetworking.org/sdn-resources/sdndefinition]
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