Session Initiation Protocol communications provider Sonus Networks and network equipment vendor Juniper Networks recently partnered to add intelligence to UC applications using software-defined networking techniques. The partnership will enable networks to scale during surges of UC traffic and give service providers the ability to refine Quality-of-Service levels to deliver comprehensive service-level agreements on voice and video calls.
How the Juniper-Sonus technology works
The session border controllers (SBCs) from Sonus' 5000 series can give application-layer information to Juniper's MX series routers and SRC Policy Engine pools. The routers' network path information can guarantee link availability and uninterrupted application delivery, while the SBCs inform the routers when sessions initiate and terminate. SBCs and routers normally operate at different layers of the Open Systems Interconnection (OSI) stack, but when they talk to one another, you get a smarter, more flexible network.
"If you look at the OSI stack … each layer runs on its own horizontal plane not talking to the layers beneath. The reason for that was, historically, there was plenty of bandwidth," explained Aashu Virmani, Sonus' senior director of corporate strategy and business development.
Today, unified communications-(UC) sessions use more bandwidth than a plain-vanilla 64K voice session. High-definition (HD) voice calls use twice as much bandwidth, while video conference calls consume 20% more bandwidth than what vendors claim. To prevent UC sessions from stopping altogether, those applications need to talk to the lower network layers in order to negotiate how much bandwidth is permissible to take. In essence, letting the application and network transport layers talk to each other makes applications less selfish.
More on Sonus Networks and SDN
Making a play for the enterprise UC market: Sonus SBC
Video interview with analyst Zeus Kerravala: How SDNs could impact UC
"In the absence of these layers talking, there is no collaboration; there's no way to ensure that on a call-by-call basis I can give you an SLA [service-level agreement]. You can only do it on a macro level. Now, we're talking about finer-grain control over the network, " Sonus' Virmani said.
Gartner analyst Akshay Sharma illustrated it this way: If a network doesn't have enough bandwidth to conduct an HD voice call with enhanced codecs, it might still have enough resources to deliver a compressed voice call. "Instead of just restricting calls, now you can have application awareness and network awareness for sessions," he said. This type of interaction moves "more towards session management, as opposed to just managing ports on boxes -- it's more holistic."
Both service providers and enterprises will benefit from this integration, Sonus' Virmani said. Service providers can make SIP [Session Initiation Protocol] trunks more programmable, and enterprises can get more from their service provider. "The enterprises can now do a lot more with the 30 to 40 megs. … [They] can use it much more smartly."
UC applications benefit from SDN
While Sonus' SBCs can scale to as many as 300 to 400 calls per second, other network elements can't achieve this in real time and at the scale a service provider needs. With the Juniper-Sonus partnership, the overall solution can scale call volumes effectively using software-defined networking (SDN) techniques rather than ordering a new dedicated appliance to support new service provider customers.
"What Sonus Networks has done is take their [SBC] and essentially turn it into a virtual machine … [that runs] on x86 devices rather than necessarily the dedicated device. By running it in a virtual network instance, everywhere that that virtual overlay is running in the network is effectively where you can place that SBC. That can give a whole new level of flexibility to Sonus in terms of where they can place this application and where they can run it in their network," explained Brad Brooks, vice president of marketing and business strategy for Juniper's software solutions division.
The integration will grow more powerful when Juniper releases its JunosV Contrail SDN controller later this year, which will allow Sonus Networks' technology to run in even more environments than Juniper's.
How UC can use SDN for IP-based communications.