Thumbs up for SBCs: UC Security, Interoperability, and Performance in the Cloud

In this tech note, I'll pick up where we left off with my last discussion on public and private cloud services with some findings from our latest Webtorials research on Unified Communications (UC) and Session Initiation Protocol (SIP) momentum; a closer look at Microsoft Skype for Business (SFB) cloud services; and some issues that should be addressed in any cloud-based UC deployments. 

In our recent 2016 Webtorials State of the Market Report, we confirmed that UC continues to be on a roll, with a major shift toward solutions being implemented using SIP. Another significant development is a move from single vendor UC solutions to multi-vendor UC solutions in the past two years.  

Among survey respondents, 35% plan to deploy cloud-based voice solutions in 2016 as an integral part of that multi-vendor deployment in 2016.  By comparison, 31% expect a premises-only solution by the end of this year, and 33% plan to have hybrid cloud/premise architectures.

On the "concerns" side of ongoing UC deployments, our research also found a pressing need for SIP session security, transcoding between VoIP-to-VoIP and VoIP-to-PCM calls, and call admission control.  These requirements topped the list for the features a session border controller needs to manage in a UC environment.  

While we didn't report-out on specific UC vendors or service providers in our State-of-the-Market analysis, it is clear that Microsoft's Skype for Business (SFB) has infiltrated as a leading vendor of choice in multi-vendor architectures, and SFB is poised to overtake incumbent UC suppliers as a market share leader.  The SFB cloud-based alternative is especially threatening to legacy premises-based UC solutions as it continues to improve on functionality and as the SFB price per subscriber/seat continues to get more competitive.    

Microsoft offers a variety of cloud alternatives that incorporate SFB, Office 365, and bundles with both, including: 

As we found in our research, UC users are concerned about how to manage security and transcoding, along with ensuring quality of service and providing support for mobile devices. Transcoding between all-VoIP calls and between VoIP and legacy systems was a particular concern with UC deployments, as was transcoding for video codecs and between a video call that includes an audio-only bridge.  

Unfortunately, the transition to a cloud service - whether from SFB or another provider, does not solve these security and transcoding issues without some additional measures.  In fact, the tendency to migrate gradually to a cloud service rather than a full-scale "rip and replace" strategy may exacerbate transcoding and security issues.  A multi-vendor or multi-generational infrastructure needs mediation between signaling systems, codecs, policy controls for users, and performance management.

Different cloud services also provide different levels of mobile device support and connectivity to wireless voice networks.  All top tier public cloud providers (including SFB) provide downloadable service apps that enable mobile devices to use a data connection for cloud service access with either a Wi-Fi access point or a service provider's mobile data service.  Some cloud providers support a seamless voice call handoff between Wi-Fi networks and the providers' mobile voice network. However, seamless roaming between voice over Wi-Fi and service providers' mobile voice networks is not always included, so calls may be dropped if a mobile user goes beyond the reach of the Wi-Fi network.   Mobile device users may also find fewer UC features supported than on a PC or laptop depending on the device type and the cloud provider's app.  

Typically, the most elegant solution to manage all of these concerns is to include session border controllers (SBCs) inside the cloud to manage security, session and call admission control, performance, and transcoding UC applications.  Because SBCs manage the sessions from end-to-end inside the domain it controls, even when controlling two different platforms, it is ideally suited and can manage all of these potential pitfalls when two different networks or platforms are connected.  Alternatively, a premises-based session border controller (SBC) can be used and may even be preferred to a cloud-based SBC when a premises-based UC platform is in place.   With Microsoft's incorporation of UC features into its Office 365 services, an SBC is as essential for this cloud service as with other UC platforms, including SFB.  

Cloud services or hybrid cloud-/premises-based planned implementations have overtaken what was the premises-only UC solution that dominated just two years ago.  Microsoft's SFB platform has contributed to this trend, and as Microsoft adds more features to its Cloud PBX service - especially with the Office 365 bundle and wider availability for native PSTN connectivity, SFB in the cloud will continue to grow in popularity.  However, just as with premises-based UC platforms, an SBC is critical to the security, interoperability, and performance of a cloud based UC infrastructure whether SFB, a public cloud, or a private cloud approach.