This blog post is part of a series called “CommScope Definitions,” in which we will
explain common terms in communications
Defined Network (SDN) is a new approach to internet protocol (IP) switching and routing architectures used in data centers and now increasingly being
applied to carrier networks. Let me
explain it this way.
you are driving a car from point A to point B, where your car is similar to an
IP packet going from server A to server B.
a traditional network, the road
signs tell you where to go–in a similar way the network of switches and routers
will forward data packets through an IP
network. However, these road signs (routing tables) may have been installed
years ago, and do not adapt to changing reality. They have no knowledge of possible
traffic jams or road works ahead, and no awareness of alternative routes to get
you to point B quicker. In traditional networks updating the road signs is nearly impossible, you would need to
send a crew to each intersection (i.e., each switch and router) to reconfigure
them manually, a slow and expensive process.
result is suboptimal use of the available road capacity and a poor driving
SDN in a network is the equivalent of bringing
in a central traffic command center directing self-driving cars. SDN controllers
use real-time traffic information and remotely steer the cars at each intersection in real-time, throughout the
network with no human intervention.
also can give applications direct control over the traffic. For example, latency
and jitter sensitive applications like voice over IP and gaming, can cruise
through the network on fast carpool lanes, while non-critical downloads or data backups are directed to take the
new level of dynamic control over the network improves performance and bandwidth. In the past, building bigger pipes (i.e.,
faster links) and over-dimensioning were reliable but expensive methods for
relieving congestion. As the demand for bandwidth explodes, this approach is no
longer sustainable. With SDN, choke
points are reduced and network
throughput is improved without resorting to widening the roads and
Key Takeaway: SDN radically
changes the network architecture by introducing concepts of centrally
orchestrated networking, enabling agile traffic rerouting depending on network
conditions, and making optimized use of the available capacity. Combined with Network
Functions Virtualization (NFV), this is driving a major transformation
within service providers. I will discuss NFV in my next blog.