This document discusses the SDN landscape and challenges. It provides an overview of Ericsson's research in packet technologies and SDN. Some key challenges discussed include navigating the hype around SDN, addressing all aspects of the ONF architecture and framework, determining the functions of the SDN controller versus NMS, whether SDN will transform carrier networks, having one controller platform for different application areas, industry traction of new open-source controller initiatives, determining the right level of split between control and data planes, programmability needs, and developing a migration strategy from legacy networks to SDN. The document advocates for experience from live network trials as SDN fits best with a DevOps model.

1. SDN Landscape
and Challenges
Attila Takacs
Manager, Packet Technologies
Ericsson Research, Hungary
EWSDN – European Workshop on Software Defined Networks
October 25-26, 2012

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Budapest
Sweden
- Kista
- Luleå
- Linköping
- Mölndal
- Lindholmen
- Lund
Tokyo
HelsinkiMontreal
Aachen
Beijing
PisaSilicon
Valley
Madrid
Ericsson Research, GLOBAl VIEW:
Packet Technologies Research Area

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The Hype…
Challenge… Navigate well

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And this is not even
the top of the CURVE…

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DefinitioN(S)
› No agreed definition… ONF is most authentic
+1
„SDN is a concept which allows networking behaviour to be defined via
software tools that enable easy modification – as opposed to behaviour that is
fixed by the design of networking equipment.”
› Some recurring components
– Decoupling control and data plane aka split architecture
– Centralized controller
– Programmability and APIs
– Open interfaces
– External applications
– Virtualization
Challenge… Address all aspects ONF Architecture & Framework

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Mapping SDN
Software
Defined
Networking
ProgrammingCustomization
On-device
“distributed”
Network-wide
“centralized”
Box SDK
NMS/OSS
Split
Architecture
Controller SW 3rd party Apps
SON
Automation
APIs
Blurred
boundary
Challenge… Functions of the SDN controller vs. NMS
Scripting
Speed

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technology evolution Model
Time
Switching/routing
Data Center Networking
Aggregation & Metro
Transport
IP Edge
Gap
Illustration
Subscriber aware forwarding/processing

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technology evolution Model
Time
Subscriber aware forwarding/processing
Switching/routing
Data Center Networking
Aggregation & Metro
Transport
IP Edge
SDN
“Simple” transport switches
and P routers
“Simple” transport switches
and P routers
Complex edge processing
and various appliances
Complex edge processing
and various appliances
Challenge… Will SDN indeed transform the carrier segment?
Illustration

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Application Areas
ENTERPRISE
RESIDENTIAL
MOBILE
cloud / data
center
Virtualization of
aggregation
network
Network
support for
cloud
Policy-based
flow steering
at edgeMulti-layer
packet & optical
transport
Home
Gateway
control
Challenge… Will we have one controller platform for all these?

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Controller “Universe”
› Open source controllers
– NOX/POX
– Trema
– Beacon
– Floodlight
– Maestro
– Ryu
– FlowER
– Mirage
– Jaxon
› Single purpose controllers
– SNAC
– RouteFlow
– FlowVisor
– OpenRoads
– FlowScale
– Hedera
– NDDI/OESS
› Commercial controllers
– ONIX
– Helios
– ProgrammableFlow
– CPlane OpenTransit
…others
Challenge… Will new open-source initiatives get industry traction?
Not a complete list!

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Split Architecture
› Connectivity check
› 50ms protection
› Control network maintenance
› …
FW
CP
“Smart”
CP
FW
Thin CP
O&M
FW
CP
Challenge… Right level of split which functions should remain distributed?
sort of Hybrid

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Programmability
› DP programmability?
› How much flexibility is
needed?
OF Future?
› Can we go with generic
chipsets?
› How to utilize SDN for new services
› Where/what is the NorthBound API?
› Network abstraction model?
› Generic Controller or use-case specific?
› Reusability of components?
“Smart”
CP
FW
Thin CP
O&M
OSS/BSS
Challenge… Tools, “languages”, components, chipsets…

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Summary
› It is not just virtualization…
› Split between CP and DP: OAM and thin control layer
› How we program the network and what flexibility is needed
– Both controller and forwarding sides
› Need a migration strategy
– From legacy to SDN and to interwork with legacy
› Align controller initiatives to leverage scale
› Need experience from live network trials
– SDN fits best to DevOps model

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