Every day, Traditional network architectures are ill-suited to meet the requirements of today’s enterprises, carriers, and end users. Thanks to a broad industry effort spearheaded by the Open Networking Foundation (ONF), Software- Defined Networking (SDN) is transforming networking architecture.
Software Defined Networking is our topic of the month. Read an executive summary of our monthly technical review.
Software- Defined Networking (SDN)
Software-defined Networking (SDN) is a new approach to designing, building and managing networks. The basic concept is that SDN separates the network’s control (brains) and forwarding (muscle) planes to make it easier to optimize each.
SDN approach to computer networking allows network administrators to manage network services through abstraction of lower level functionality. This is done by decoupling the system that makes decisions about where traffic is sent (the control plane) from the underlying systems that forward traffic to the selected destination (the data plane). The inventors and vendors of these systems claim that this simplifies networking. SDN requires some method for the control plane to communicate with the data plane. One such mechanism, Open Flow, but other mechanisms could also fit into the concept.
In this environment, a Controller acts as the “brains,” providing an abstract, centralized view of the overall
network. Through the Controller, network administrators can quickly and easily make and push out decisions on how the underlying systems (switches, routers) of the forwarding plane will handle the traffic. The most common protocol used in SDN networks to facilitate the communication between the Controller (called the Southbound API) and the switches is currently OpenFlow.
An SDN environment also uses open, application programmatic interfaces (APIs) to support all the services and applications running over the network. These APIs, commonly called Northbound APIs, facilitate innovation and enable efficient service orchestration and automation. As a result, SDN enables a network administrator to shape traffic and deploy services to address changing business needs, without having to touch each individual switch or router in the forwarding plane.
SDN is Not OpenFlow
Often people point to OpenFlow as being synonymous with SDN, but it is only a single element in the overall SDN architecture. OpenFlow is an open standard for a communications protocol that enables the control plane to interact with the forwarding plane. It must be noted that OpenFlow is not the only protocol available or in development for SDN – for example, the Open Networking Lab (ON.Lab) will soon release an open source Network OS, called ONOS.
The Benefits of SDN
With a centralized, programmable network that can automatically and dynamically address changing requirements, SDN offers:
The Near-Term Future
The SDN revolution today is extremely turbulent. Presently, its development is focused heavily on the large data center and virtualization space. It may very well evolve into a useful tool for the enterprise and service provider space in the future, but there is a lot of work that needs doing by everyone involved before that can happen.
For more ...... See Vega's June Newsletter
SDN approach to computer networking allows network administrators to manage network services through abstraction of lower level functionality. This is done by decoupling the system that makes decisions about where traffic is sent (the control plane) from the underlying systems that forward traffic to the selected destination (the data plane). The inventors and vendors of these systems claim that this simplifies networking. SDN requires some method for the control plane to communicate with the data plane. One such mechanism, Open Flow, but other mechanisms could also fit into the concept.
In this environment, a Controller acts as the “brains,” providing an abstract, centralized view of the overall
An SDN environment also uses open, application programmatic interfaces (APIs) to support all the services and applications running over the network. These APIs, commonly called Northbound APIs, facilitate innovation and enable efficient service orchestration and automation. As a result, SDN enables a network administrator to shape traffic and deploy services to address changing business needs, without having to touch each individual switch or router in the forwarding plane.
SDN is Not OpenFlow
Often people point to OpenFlow as being synonymous with SDN, but it is only a single element in the overall SDN architecture. OpenFlow is an open standard for a communications protocol that enables the control plane to interact with the forwarding plane. It must be noted that OpenFlow is not the only protocol available or in development for SDN – for example, the Open Networking Lab (ON.Lab) will soon release an open source Network OS, called ONOS.
The Benefits of SDN
With a centralized, programmable network that can automatically and dynamically address changing requirements, SDN offers:
- Service provisioning speed and agility: Setting up networks in an SDN can be as easy as creating VM instances, and the way SDNs can be set up is a far better complement to VMs than plain old physical networks.
- Network flexibility and holistic management: SDNs enable “network experimentation without impact” - meaning one can leap over the limits imposed by SNMP and experiment freely with new network configurations without being hamstrung by their consequences.
- Better and more granular security: VMs have made network security a headache and a half. SDNs can provide the kind of fine-grained security for apps, endpoints and BYOD devices that a conventional hard-wired network cannot.
- Efficiency and lower operating expenses: The exact cost savings of SDNs is still in doubt - for example, it's unclear whether it might simply shift costs to controllers and software. Still, 50% of the administrators surveyed who use SDNs said they sold the technology to their business executives as a money-saving methodology. And while many of those polled see lower hardware costs as a big SDN selling point, the bigger opportunity is lower opex costs due to improved network management efficiency, according to the report.
- Virtual network services, lowered capex/ OpEX: Even if the biggest benefits for SDNs will be in big-league data centers, there’s still plenty of ways for enterprises to lower their capex - both by making better use of what enterprises already have, and by lessening dependencies on proprietary hardware and dedicated appliances.
The Near-Term Future
The SDN revolution today is extremely turbulent. Presently, its development is focused heavily on the large data center and virtualization space. It may very well evolve into a useful tool for the enterprise and service provider space in the future, but there is a lot of work that needs doing by everyone involved before that can happen.
For more ...... See Vega's June Newsletter