2. 2
Definition of SDN
2
(c) Copyright 2013 Fujitsu Network Communications, Inc. All Rights Reserved.
SDN Definition 1:
Source: paraphrased Wikipedia definition
An approach to computer networking which abstracts
the control plane and the data plane
Enables management of network services through
abstraction of lower level functionality into virtual
services
Provides programmable central control of networks
without requiring physical access to the network HW
( &
中国电信“云计算”研究中心 3
3(c) Copyright 2013 Fujitsu Network Communications, Inc. All Rights Reserved.
Decouples systems that makes decisions (match &
action) about where traffic is sent (control plane) from
underlying systems that forwards traffic to selected
destination (data plane)
3. 3
SDN Definition 2:
Source: Derived from ONF white paper
An emerging network architecture where network
control is decoupled from forwarding and is directly
programmableprogrammable
Enables the underlying infrastructure to be abstracted
for applications and network services, which can treat
the network as a logical or virtual entity
Network intelligence is (logically) centralized in
software-based SDN controllers, which maintain a
中国电信“云计算”研究中心 4
4(c) Copyright 2013 Fujitsu Network Communications, Inc. All Rights Reserved.
,
global view of the network
SDN Definition 3
Source: ITU-T draft SDN framework
recommendation
A networking technology which allows centralized,
programmable control planes and data plane
abstractionabstraction
Control and data planes are separated, so network
operators can directly control and manage their
virtualized resources and networks
中国电信“云计算”研究中心 5
5(c) Copyright 2013 Fujitsu Network Communications, Inc. All Rights Reserved.
4. 4
SDN Definition 4
Source: Heavy Reading
An architectural concept that encompasses the
programmability of multiple network layers – including
management network services control forwardingmanagement, network services, control, forwarding
and transport planes
to optimize the use of network resources, increase network
agility, unleash service innovation, accelerate service time-to-
market, extract business intelligence and ultimately enable
dynamic, service-driven virtual networks.
中国电信“云计算”研究中心 6
6(c) Copyright 2013 Fujitsu Network Communications, Inc. All Rights Reserved.
SDN Definition 5
Source: Infonetics Research
A subset of programmable networks
Enable networking applications to request and
manipulate services provided by the networkmanipulate services provided by the network
and allow the network to expose network state back to the
applications
2 common types of SDNs
API
Control plane abstracted
from data plane
Programmable Networks
SDNs
SDN
SDN “API” “Control Plane”
中国电信“云计算”研究中心 7
from data plane
7(c) Copyright 2013 Fujitsu Network Communications, Inc. All Rights Reserved.
Network
APIs
protocols
* IETF SDNP
* ALTO
Control Plane
Protocols
* OpenFlow
* PCE
* BGP-TE
12. 12
SDN标准化现状 - IETF
IETF早期有两个与SDN相关的研究项目/工作组，分别是
ForCES和ALTO。
目前，IETF新成立了I2RS(Interface to the Routing System)工
作组 用以定义对路由系统开放的需求 场景和架构作组，用以定义对路由系统开放的需求、场景和架构
IETF主张在现有的网
络层协议基础上，增加
插件（plug-in），并在
网络与应用层之间增加
SDN Orchestrator进行
能力开放的封装，而不
是 直 接 采 用 O fl
中国电信“云计算”研究中心 22
是 直 接 采 用 Openflow
进行能力开放，目的是
尽量保留和重用现有的
各种路由协议和IP网络
技术
SG13下一代网络开展SDN研究，已经在未来网络课题组开展了Y.FNsdn和
Y.FNsdn-fm等项目研究，分别对应SDN的需求和架构研究
由中国电信主导，在现有网络（NGN）中引入SDN的需求和架构研究，开
展需求、架构的研究
SDN标准化现状 – ITU-T
Data Plane
(Specialized Hardware)
Control Plane
Data Plane
(Forwarding Abstraction)
Control Plane
Network OS
Controller
(NetworkOS)
Separation
Network OS
SDN
Languages
a.1 control and data planes tightly-coupled b.1 control and data planes separated
SDN
Apps
中国电信“云计算”研究中心 23
a.3 single physical network
b.3 Multiple, isolated, virtual networks
Client
Client
Server
Server
Mobiltye.g., Content Routing
Energy efficient forwarding
a.2 distributed control of network equipments
b.2 centralized, programmable control of network equipments
a. Current networking technology b. SDN networking technology
Y.FNsdn
