Sonus Networks is tightening its partnership with Juniper, announcing yesterday that its virtual session border controller (SBC), an element of voice-over-IP and voice-over-LTE (VoLTE) deployments, is being integrated with the Juniper Contrail controller.

It's an extension of an alliance, announced in 2013, which let Juniper run a Sonus SBC on the JunosV App Engine, an x86 card that plugs into Juniper's routers. Now, the capability is coming to Juniper's software-defined networking (SDN) platform as well. Contrail will be able to spin up and take down virtualized SBCs, and move them around the network, prompted by commands from Juniper's user interface.

Target customers are the large service providers that want to offer unified communications as a service or SIP trunking. Contrail would be able to set up video calls on the fly and keep quality-of-service applied to the traffic flows, for example, says David Boland, senior product marketing manager for Sonus.

The integrated SBC could also provide a way to bring up those services in new geographic areas without incurring truck rolls.

Sonus is open to tying the virtual SBC to other SDN controllers but would probably only do so if asked, Boland says. "Right now, we have some joint customers with Juniper that this fits nicely with," he says.

The virtual SBC is called the SBC SWe — "SWe" standing for "software edition," the umbrella term for all of Sonus' software-based components. This week, Sonus added two entries to the category: a software-based Diameter signaling controller and a policy and routing engine, respectively called the DSC SWe and PSX SWe.