Software-defined networking (SDN) is bringing the cloud to the broadband edge. As a recent contributor to SDNCentral noted, we are all becoming “cloudinians” now – not least of all network operators, who have the opportunity to leverage the power of SDN and network functions virtualization (NFV), combined with the scalable web and cloud technologies currently employed in large-scale data centers, to revolutionize how broadband services are delivered. Broadband providers can exploit SDN and NFV to extend the cloud out to the service edge, significantly reducing the cost and complexity of service delivery by increasing operational efficiencies. At the same time, operators will be able to rapidly create and deploy new, personalized services that increase market penetration and improve customer satisfaction.
SDN and NFV Enable Network Refactoring
SDN and NFV enable “network refactoring” at the broadband service edge, which involves repartitioning and reorganizing software and hardware functions while preserving the functional behavior of the network, allowing operators to:
- Phase out costly hardware platforms based on custom silicon
- Execute software-based functions on low-cost NFV platforms
- Eliminate legacy components and protocols in the OSS infrastructure
Refactoring opens the door for operators to exploit the cost efficiencies and open programming tools and methodologies of modern IT systems and software. By stripping unneeded network-facing functions from the OSS infrastructure, operators can approach service creation and orchestration in a radically different way, giving customer-facing OSS applications direct programmatic access to network resources using familiar interfaces: web services APIs and message queues. The net result is lower complexity and cost, accompanied by significant gains in service agility and velocity.
For example, existing Broadband Network Gateways (BNGs) are based on provider edge router platforms in which complex service management functions are implemented in software embedded in the router’s proprietary OS. Using SDN and NFV, these functions can be refactored and implemented in a programmer-friendly open software environment running on a low-cost server platform – an SDN controller optimized for broadband service delivery. BNG network connectivity and packet processing functions can be refactored onto low-cost NFV infrastructure – an SDN-controlled, software-based Ethernet switch that performs high-speed packet forwarding. These two components allow operators to deploy a “software-defined BNG” based on SDN and NFV technologies.
Eliminate Unnecessary Network-Facing Middleware
Existing broadband service delivery infrastructure incorporates a number of OSS components that serve as network-facing “middleware” between the customer-facing OSS applications and the underlying network elements, including BNGs. These components include DHCP, Radius, LDAP and policy servers that the OSS applications populate with data for managing service activation and control. There is no direct programmatic control of the underlying network by the OSS service management applications – everything transits this intermediate software layer. The behavior of network elements is determined by the data populated in these servers, and these behaviors are governed by a strict set of rules codified in a rigid set of network protocols. Organizationally, OSS application developers and network engineers live in two different worlds that are joined only at this middleware boundary. The net result is a constrained service creation and delivery model that supports relatively primitive services and typically requires months to implement even simple modifications to service offerings.
A “software-defined BNG” can use scalable web and cloud technologies at the broadband edge, erasing the boundary created by the existing layer of network-facing middleware, allowing the new network infrastructure based on SDN and NFV to operate in the same open programming environment as IT systems and software. In this model, network engineers and OSS developers are no longer separated by a technological divide – they can now speak the same common language.
SDN and NFV Streamline Service Orchestration
The big payoff for operators who apply SDN and NFV at the broadband edge comes not from significantly reduced cost and complexity, but from the ability to streamline service orchestration and rapidly create, deploy and modify new services that better meet individual customer needs. Operators will be able to accomplish in weeks or even days what takes months to do today. They will become more flexible and agile in responding to changing market conditions and competitive threats. Customers will enjoy the benefits of services that can be activated and modified on-demand, automatically through self-service web portals.
With both customer-facing service management applications and the underlying SDN/NFV broadband infrastructure operating in an open software environment based on a common set of scalable web and cloud technologies, application developers now gain direct programmatic control over all aspects of the underlying network infrastructure. Instead of populating an intermediate layer of servers with service management data, OSS applications and the underlying SDN controller now have direct programmatic access to a common set of databases, including the service catalog and the account/customer/device database. Service activation and dynamic service control are now straightforward. Applications interact directly with the SDN controller, which is in turn able to directly program elements in the underlying network infrastructure using an SDN-based control protocol such as OpenFlow.
More than two decades ago Sun Microsystems coined the phrase “the network is the computer.” While this may be true, it has taken all these years for the industry to finally develop the technologies, tools and methodologies for easily programming this computer. By deploying solutions based on SDN and NFV, broadband providers will finally be able to fully unleash the power of the network for the benefit of their customers.