Note: This is the last installment of a series in which contributors elaborate
on each of the five game-changes featured in CommScope’s latest Global Enterprise Survey.
networking (SDN) has been a hot topic in the network world for the past two
years. Many folks aren’t aware of what it is, what it can do and its potential
benefits. The greatest benefit of SDN is the potential savings on total cost of
ownership. The savings are only considered potential because SDN still needs
more real cases to prove its full cost-savings capability. The savings
potential has generated so much interest that the number of requests I receive
to speak or write about SDN is steadily increasing.
To explain how SDN works, we can start with a network device such as a router, switch or firewall. This device makes the decision of
handling network traffic on its own. This individual decision-making approach may
not be optimal. SDN transforms this traditional, discrete approach to a new holistic
approach. SDN is a networking architecture that provides a capability to control
or “define” network traffic flows, security policies or network topology by
dynamically programming network devices. The programming capability iscentralized and hosted on one or a few standard servers known as an SDN
controller. In brief, the SDN controller is the brain of SDN networks.
The figure below shows a traditional network layout as it
compares to an SDN network layout:
SDN is a recent development and is in its infant stage of
the life cycle. Service providers or cloud providers are the early adopters of SDN.
These adopters tend to integrate SDN with their cloud, enabling them to better
control or shape their networks in a data center or across multiple data
It is my belief that SDN requires a robust physical layer
(cabling) infrastructure. Whenever and wherever an SDN controller programs
network devices to operate network traffic flows, the underlying connectivity
must be available to support the operations. For example, if there is a large
volume of data to be transferred across networks, the traditional approach requires
the data go through a firewall. However a large volume of data passing through
a firewall may significantly increase the workload of the firewall and reduce
the responses to other application requests. SDN can solve this problem by looking
at the entire network, identifying a path, and creating a secure application to
let the data bypass the firewall -this process is known as firewall
cut-through. No matter which path SDN identifies to route data flows, the
underlying connectivity must be up and available anywhere at any time.
It is important to know that SDN relies heavily on a
high-bandwidth and high-performance physical layer (cabling) infrastructure.
SDN essentially is network virtualization and a physical network device may be
shared by multiple virtual networks. For example, SDN can slice a data center
network for multi-tenancy operations. Each slice consumes a portion of the
networking resource but is presented logically as a complete, secured and
isolated network for individual networking service -an example of a service can
be a private, public or hybrid cloud. A high-bandwidth cabling infrastructure
is needed to provision the necessary networking capacity shared by
multi tenants. A tenant can represent a networking service such as a cloud. The
cloud basically is a service and a high-performance cabling infrastructure is
needed to guarantee cloud performance specified in the service level agreement.
The 10, 40 or even 100 Gigabit Ethernet (GbE) is recommended to build the
infrastructure for SND. The 10/40/100 GbE doesn’t only provide high bandwidth
but also provides the low latency needed to achieve networking performance
In the latest CommScope
Global Enterprise Survey, 32 percent of respondents indicated that 40GbE
and 100GbE would have a significant impact on future operations. So, it makes
sense to look at the SDN solution and see how it may work into the IT strategy.
If you have any questions about SDN or how it relates to data
center cabling infrastructure, leave a comment below and I will get back to you
as soon as I can.