As network functions virtualization continues to gain momentum and traction in the industry, communication service providers are wrestling with how to transition existing network elements to cloud-based or virtualized environments. If they don't have a smooth transition path, they risk being left behind and are otherwise limited to either greenfield NFV deployment options or point solutions to maintain dual environments for different services.
Distributed architectures with separate signaling and media functions allow the transition to a cloud environment to occur smoothly. This architectural separation is important because it offers communication service providers (CSPs) significant deployment flexibility and optimized solutions for transitioning to network functions virtualization (NFV), both technically and from a business perspective.
An example application of this concept can be highlighted with the distributed session border controller (D-SBC).
The benefits of separating signaling and media for SBC functionality are numerous:
Hybrid deployments -- Separation of signaling and media allows for hybrid deployment topologies for NFV deployments whereby SBC signaling is processed in the NFV cloud and the media is provided in-network. This also allows for signaling functions and media functions to be smoothly migrated from the network to the cloud and via flexible timeframes.
Independent scalability -- In a traditional network environment as traffic grows, more equipment is added to increase the signaling and registration scale, which may leave media resources either under or over-allocated. In a distributed cloud environment, signaling and media resources can be scaled independently to meet the CSP's exact needs and be driven by actual service requirements.
Optimizing resources -- In some environments, where scaling is driven by signaling requirements, there may be excess media resources available that remain unused. Likewise, in applications where scaling is driven by media bandwidth consumption such as HD voice and video, there may be excess signaling capacity that remains unused. In a distributed environment, media and transcoding resources are independently scalable and sharable across multiple SBCs, allowing media processing and transcoding assets to be aggregated across the network or cloud, and signaling independently scalable in the cloud.
Cost efficiency -- In a distributed environment, media and transcoding are effectively viewed as a "common" pooled resource, not just centralized, enabling an SBC to no longer be limited by its local media resources. Basically, it can use any media resource available in the network, enabling maximum cost efficiency and savings, especially for expensive transcoding resources. This results in significant capex savings by purchasing fewer media and transcoding elements.
Data center optimization -- Physical separation of signaling and media resources creates the ability to locate these two functions in geographically separate locations in multiple physical NFV data centers to improve geographic resiliency and business continuity. Additionally, if the elements are fully redundant they can offer enhanced resiliency provided by the ability to use media resources deployed on another geographic site in the network in the case of complete site outage.
Performance efficiency -- In general, media requires significantly more bandwidth than signaling. Rather than burdening the entire data center with media traffic infrastructure, in a distributed environment the CSP can elect to optimize the data center design to ensure that certain types of equipment are used solely for media and not for signaling and management, significantly improving performance.
As you can clearly see, separating signaling control and media processing functions offers service providers an opportunity to not only smoothly transition in-network functions to NFV, it also optimizes deployments, expenditures and performance for NFV-based deployments, while more importantly offering dramatically improved network quality and end user experience.
— Sanjay Bhatia, Vice President, Solutions Marketing & Strategy, GENBAND, special to The New IP