Network functions virtualization (NFV) and software-defined networking (SDN) are emerging to be disruptive technologies, introducing many innovations in the service provider network architecture. Service providers are looking at ways of optimizing cost, increasing ROI, and simplifying the management of their network infrastructure, and NFV and SDN provide them with unlimited possibilities.
Until now, innovations in networking were mostly around increasing the throughput or packet forwarding capacity of network devices such as routers and switches. However, NFV has changed the way in which networks were designed, developed and deployed. NFV provides significant opportunities for service providers to optimize their network architecture, launch newer services, and monetize better.
Here are a few NFV applications that are getting more traction from service providers and original equipment manufacturers (OEMs).
Virtualized Wireless LAN Controller
Today, WLAN controllers use proprietary protocols to manage access points deployed in the network. While using proprietary protocols may be sufficient in an enterprise or campus deployment where access points are supplied by a single vendor, it may be inadequate for a multivendor deployment, such as a carrier WiFi deployment where service providers roll out thousands of hotspots. This brings the need for a standard protocol, such as the Control And Provisioning of Wireless Access Points protocol (CAPWAP) or OpenFlow/OF-Config, for managing access points.
With service providers adopting SDN, it becomes easy to virtualize select WLAN functions. For example, the WLAN Access Controller (AC) function in the carrier WiFi network can be virtualized and run on the cloud. AC functions such as radio management, policy management, and roaming can be migrated to and managed from the cloud. A cloud-ready carrier WiFi solution provides the following benefits:
- Centralized management and monitoring of both wired and WLAN networks
- Highly scalable architecture
- Increased programmability and fine-grained control of WLAN functions
- Unified policies for wired and WLAN networks. Policies can be created, managed and propagated from a central location for both wired and WLAN networks. For example, user Joe, a Gold subscriber of the service provider, will be authenticated and authorized by the same SDN policy management application, regardless of whether he accesses the network from the wired/DSL connection or the public WLAN hotspot or from a mobile wireless network.
Virtualized Customer Premises Equipment (CPE)
Service providers can significantly cut down on costs and provide additional monetizable services to their subscribers by deploying virtualized CPEs. Today, a CPE provides a number of network functions such as firewall, access control, policy management, and discovering/connecting devices at home using DLNA or UPnP. Virtualizing select control plane functions of the CPE and moving them toward the network edge or towards the cloud provides the following benefits:
- Lower CPE costs
- Ability to roll out additional features to subscribers without upgrading the CPE or residential gateway
- Ease of management and service activation or customization – since most services are offered from the virtual CPE running on the cloud
- Centralized control and management of subscriber services.
Adopting a SDN architecture allows the CPE functions to be managed by standard protocols such as OpenFlow and OF-Config. OpenFlow can be used for flow-table management in the CPE. OF-Config can be used to manage the device configuration of the CPE. Residential gateway functions can run on lightweight hardware using a low CPU/memory footprint operating system. This will result in cost reduction of the CPEs and efficient management of the CPE functions.
Service provider OSS typically consists of point solutions designed to manage a range of services such as Internet, VoIP, videoconferencing, and content delivery networks (CDN). OSS architectures use nonstandard network management technologies to manage the network. The closed and proprietary nature of OSS implementations reduces the programmability, thereby eliminating the possibility of dynamically provisioning new network services. When a service provider adopts an NFV- and SDN-ready OSS architecture, it can realize the following benefits:
- Management of various network functions can be unified under standard SDN-based management technologies (for example, OF-Config and OpenFlow protocols).
- OSS applications become more open, which in turn allows service providers to offer federation services.
- Virtualized OSS functions allow a service provider to provide value-added services – for example, dynamically varying bandwidth for applications as opposed to static provisioning of bandwidth.
NFV provides unlimited possibilities for service providers to realize the power of their network infrastructures to offer new and monetizable services to their customers. However, NFV is not about just running today’s network function or service on top of virtual machines. In fact, that is the easiest part of the solution. There are lots of aspects that need to be looked at before virtualizing network functions:
- What are the network functions that provide maximum ROI when virtualized?
- How do you make the virtualized network function (VNF) seamlessly integrate into SDN and cloud architectures?
- What APIs does the VNF expose for ease of management?
- How does the architecture scale for increased workloads or provide elasticity?
- What SDN controllers or cloud operating systems does the architecture support?
- How does the VNF interoperate with legacy, non-virtualized network elements?
- How can the VNF support a multi-tenant architecture for sharing the network infrastructure with multiple applications?
- How are the virtualized functions running on the cloud mapped to the physical network elements?
- How do you bring in high availability and automatic service failover/recovery?
- How do you integrate with existing network management infrastructure?
Virtualization of network services and applications provides a huge opportunity for OEMs and service providers to come up with innovative offerings to their customers. Though there are a lot of unknowns and challenges in the NFV segment, there is a huge interest from the industry to solve the problems in today’s network architecture by leveraging the power of NFV. We can expect to see more converged SDN and NFV applications in the market soon.