Transcript
Software-defined networking: the service provider perspective
An architecture based on SDN techniques gives operators greater freedom to balance operational and business parameters, such as network resilience, service performance and QoE against opex and capex. every year1. One of the root causes of network complexity lies in the traditional
way technology has developed. The design of network elements, such as routers and switches, has traditionally
been closed; they tend to have their own management systems with vertically
integrated forwarding and control components, and often use proprietary interfaces and features. The goal of network management is, however, to ensure that the entire network behaves as desired – an objective that is much more important than the capabilities of any single network element. In fact, implementing end-to-end networking is an important mission for most operators,
and having to configure individual
network elements simply creates an unwanted overhead.
Network-wide programmability – the capability to change the behavior of the network as a whole – greatly simplifies the management of networks. And the purpose of SDN is exactly that: to be able to modify the behavior of entire networks
in a controlled manner.
The tradition of slow innovation in networking needs to be broken if networks
are to meet the increased demand for transport and processing capacity.
By integrating recent technological advances and introducing network-wide abstractions, SDN does just that. It is an evolutionary step in networking.
Telephony has undergone similar architectural transitions in the past. One such evolution took place when a clear separation between the functions
Ericsson’s approach to SDN goes beyond the data center addressing issues in the service-provider environment. In short Ericsson’s approach is Service Provider SDN. The concept aims to extend virtualization
and OpenFlow – an emerging protocol for communication between the control and data planes in an SDN architecture – with three additional key enablers: integrated network control; orchestrated network and cloud management;
and service exposure.
There is no denying that networks are becoming increasingly complex. More and more functionality is being integrated into each network element, and more and more network elements are needed to support evolving service requirements – especially to support rising
capacity needs, which are doubling ATTILA TAKACS, ELISA BELLAGAMBA, AND JOE WILKE
The traditional way of describing network architecture and how a network behaves is through the fixed designs and behaviors of its various elements. The concept of software-defined networking (SDN) describes networks and how they behave in a more flexible way – through software tools that describe network elements in terms of programmable network states.
The concept is based on split architecture,
which separates forwarding functions from control functions. This decoupling removes some of the complexity
from network management, providing operators with greater flexibility
to make changes.
BOX A Terms and abbreviations
API application programming interface
ARPU average revenue per user
CLI command-line interface
DPI deep packet inspection
GMPLS generalized multi-protocol
label switching
L2 Layer 2
L3 Layer 3
L2-L4 Layers 2-4
M-MGW Mobile Media Gateway
MME Mobility Management Entity
MSC-S Mobile Switching Center Server
NAT Network Address Translation
NMS network management system
ONF Open Networking Foundation
OSS/BSS operations and business support systems
PE provider edge device
PGW Packet Data Network Gateway
RG residential gateway
RWA routing and wavelength
assignment
SDN software-defined networking
SGW Service Gateway
SLA Service Level Agreement
VHG virtual home gateway
VoIP voice over IP
WAN wide area network
2
ERICSSON REVIEW • FEBRUARY 21, 2013
New network abstraction layers