The session border controller has become ubiquitous. Many organizations migrating away from PRI and T1 connections to the PSTN move to SIP trunking. With SIP trunking, the session border controller (SBC) becomes the function that protects the IP PBX from network intrusions, but also provides network management, transcoding, and business continuity.
SBCs as we know them today continue to evolve. Two of the top trends in the evolution of the SBC are the move toward virtualized SBCs in the cloud and the growing importance of security as a critical capability of the SBC. Now SBCs could be an appliance or could be software implemented in other devices such as an IP PBX.
Experts Speak Out
It can be hard to keep up with the market changes, so I've contacted two experts in the SBC space to gather their opinions about how the SBC is evolving: Steven Johnson, president of Ingate Systems, and Alan Percy, senior director of product marketing at TelcoBridges.
"The SBC has evolved substantially since it was invented to allow inbound calls to a network protected by a firewall," Johnson said. Today, SBCs come with functionality to allow remote users to do far more than simply take inbound calls. They can access the IP telephony system, prioritize calls to ensure quality of service, offer diagnostic capabilities to isolate and resolve problems, provide a location for the collection of call metrics and performance, resolve differences in behavior between vendors and service providers, and support routing of calls in sometimes very complex ways, he said.
Modern SBCs support not just SIP but also WebRTC, a protocol that allows peer-to-peer connections without the need for a service provider, Johnson said. This is very interesting because it has led to a paradigm shift from a service provider-centric model to peer-to-peer interaction. The service provider-centric model has been the norm for more than 100 years, but with the intelligence of these new class of SBCs, we are at the threshold of a major structural change in the way that communications is enabled, he said.
"Our vision suggests that, in time, the SBC will become a node on the network which serves in all the capacities it does today, but as a decentralized intelligence point," Johnson said. "In this role, it will be used to enable traffic into and out of an enterprise, secure that traffic from malicious actions, route the traffic as appropriate, integrate various protocols, and capture the utilization of the network for billing purposes."
Traditionally, Percy said, SBCs and gateways have been appliances sold under a Capex model with maintenance support. Meanwhile, more organizations are migrating voice applications to the cloud, which have a completely different business model based on usage. The cloud model allows new services to be created and launched with little up-front costs; it also allows a user base to develop organically while the underlying infrastructure grows to meet the demand, he said.
"'Pay as you grow' is the norm with Web applications, and for communications applications to meet the needs of the next generation, they too will have to adopt a 'pay as you grow' business model," Percy said. The SBC has a role to play in all of this.
Hear from more SBC experts at Enterprise Connect 2018, in the session, "Trends in Session Border Controllers: Virtualization & Security," taking place Tuesday, March 13, at 8:00 AM. Gary Audin will be joined by executives from AudioCodes, Dialogic, Edgewater Networks, Ribbon Communications and Oracle Communications to discuss the evolving SBC. If you haven't yet registered for Enterprise Connect (March 12-15), register now using the code NOJITTER to save an additional $200 off the Early Bird Rate or get a free Expo Plus pass.
