Software Defined WAN (SD-WAN) is a specific use-case of Software-Defined Networking (SDN) technology applied to simplify the management of multiple enterprise WAN links. SD-WAN promises to drastically reduce the total overall cost by facilitating the selection of the best WAN connection based on cost of the link, application type and nature of the traffic. Many enterprises are looking to replace (or augment) their IP VPN MPLS based services using much lower cost options through SD-WAN. I already wrote in a previous blog on the role of SPs in the SD-WAN world.
The basic components of an SD-WAN architecture are:
Customer Premises Equipment (CPE), capable of using multiple WAN connections with application based routing.
SD-WAN Controller: Centralized service used to set policies and management for all the CPEs. The controller also collects analytics of the service. In managed SD-WAN models, the SD-WAN controller requires multi-tenant capabilities
SD-WAN User interface: User-interface, working in conjunction with the SD-WAN Controller that provides Management and Visibility of the service to the end user.
The implementation of a managed SD-WAN service consists of setting up the centralized components and its integration with the rest of OSS and BSS systems. In order to reduce the overall cost, most SD-WAN implementations provide a zero-touch provisioning (ZTP) model. ZTP allows end-users to simply connect the CPE to all WAN and LAN connections in each branch-office. The CPE will automatically find the controller that after authenticating will download the specific configuration to each site.
Physical or Virtual SD-WAN CPE?
Until this point, there is no clear requirement for a Virtualized CPE platform. In fact, many SD-WAN vendor implementations are based on a small physical CPE with multiple network interfaces. Technically, a virtual or a physical CPE implementation works fine, and when cost is the main requirement, the physical platform tends to win.
SD-WAN simplifies the connectivity to private and public clouds and is seen for Enterprises as a great mechanism to manage the use of hybrid cloud architectures from the different branch offices. Many Service Providers are looking to position themselves, as a key partner to manage the Hybrid Cloud connectivity for Enterprises, so SD-WAN is a critical step for that. However, SD-WAN is just one of the enablers for Hybrid Cloud connectivity.
In the journey to Hybrid Cloud, beyond SD-WAN, Enterprises will require managed Security services, application performance and visibility of their traffic. Therefore, Service Providers should be considering launching a variety of services along with their SD-WAN deployment. In this context, cost savings are not the only requirement, and agile service delivery becomes critical.
A physical CPE deployment, often translates into multiple truck rolls to add additional functionality, while a virtual implementation, can be updated using a centralized model. Virtual CPE for SD-WAN simplifies the delivery of new services, reduces it’s cost, increases time to market, and provides an overall improved experience.
To succeed in the SD-WAN space, SPs will need a differentiated service with the ability to adapt rapidly to new enterprise requirements. Everything on-demand and in a pay-as-you go approach, minimizing the additional rollout costs. In this context is where a virtualized CPE platform is fully justified.