Dialogic Blog

Bringing Carrier Grade to the Cloud with Virtualized SBCs

by Jim McLaughlin

Aug 26, 2016 9:30:00 AM

Based on current forecasts, the Network Functions Virtualization (NFV) market will top $15 billion by the year 2020.  Clearly, telecom service providers worldwide are embracing the transition from hardware-centric to software-focused architectures – and for good reasons.  NFV-based solutions promise not only CAPEX cost savings from the use of commodity computing platforms, but also reduced time-to-market for multivendor ecosystem solutions, and an ability to automate operations through the use of capabilities such as service chaining and traffic-based capacity scaling.  With such compelling value propositions, NFV may even have the potential to accelerate retirement of the many legacy TDM switches that are still in service around the globe.

The widespread roll out of IMS VoLTE and WebRTC technologies in the coming years is expected to drive exponential growth in end-to-end IP-based real-time communications.  Accordingly, network operators should probably expect a similar increase in the number of security, signaling, and media interoperability challenges that must be addressed.  As a result, any impression that session border controllers (SBCs) might somehow have a diminished role to play within cloud-based telecom networks could not be further from the truth:  Session border controllers will remain mission critical as public and private clouds are deployed to support IP-based real-time communications.  Moreover, while there will always be a need for hardware-based SBCs, the realization of NFV-based automated clouds will require the use of virtualized SBCs that are capable of delivering carrier-grade performance despite being 100% software-based and decoupled from underlying hardware platforms.


The business and operational benefits of clouds are clear.  What is less obvious is how traditional hardware-based SBCs can be re-architected into software-only virtualized network functions (VNFs) capable of delivering carrier-grade performance.  While SBCs were originally deployed simply to secure networks against fraud and malicious attacks, SBCs today also support real-time signaling manipulation and processor-intensive media transcoding features that ensure seamless network interconnection and superlative quality of service.  With SBCs responsible for simultaneously controlling both SIP signaling and RTP media flows, the transition from COTS hardware to cloud software can be complex, and implementation challenges can arise due to excessive time delays introduced by multiple layers of operating systems and hypervisors. 

For SBC developers, the pivot from building monolithic hardware-based solutions to designing software-only virtualized network functions requires a fundamentally different approach.   SBCs are critical to the operation of real-time networks, and fortunately, the telecom industry has identified multiple design techniques that enable developers to create virtualized network functions capable of delivering carrier-grade performance and reliability within cloud environments.    One technique for optimizing the performance of virtualized SBCs involves decomposing functionality into the basic components of security, signaling interworking, and media transcoding, for example, so that each component can be independently optimized and rapidly scaled.   A second technique for the successful design of virtualized SBCs involves classifying each VNF component according to whether it operates in a stateful (requiring storage of real-time session information) or stateless manner so that compute, memory, and networking resources can be optimally allocated as required.

By enabling both CAPEX and OPEX reductions, and decreasing time-to-market for new applications, cloud-based networks promise disruptive changes that will ultimately facilitate the large-scale roll-out of IMS VoLTE services globally.  Within virtualized environments, SBCs remain critical for ensuring the security and carrier-grade performance attributes that differentiate service providers from OTT players.  Clearly, each telecom network is unique, and multiple paths forward are possible.  However, an incremental approach that deploys virtualized SBCs in public or private clouds today will not only provide immediate benefits, but will also position network operators to rapidly realize all of the incremental benefits that NFV platforms promise to deliver over the coming years.

Wondering whether a software-based SBC is right for your network?  Dialogic can help!

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Topics: VoLTE/VoWifi & IMS