Companies are moving towards Network Function Virtualization (NFV) in a big way. NFV is an initiative undertaken by companies and communications service providers (CSPs) to virtualize the network services that are now being carried out by proprietary, dedicated hardware. As businesses successfully adopt NFV they will decrease the amount of proprietary hardware that's needed to launch and operate network services. Businesses are looking to NFV to deliver a number of benefits, including operational savings, lower CapEx costs, increased agility and flexibility to scale.
When it comes to the communications stack there are a number of capabilities that are moving towards NFV and the cloud at breakneck speed, from telephony and PBX’s, to UC to video conferencing. One concept that has been gathering a lot of attention on the NFV-front is virtualizing session border controllers. SBCs have traditionally been deployed on purpose-built hardware with custom DSP’s that are designed to excel at the sophisticated security and interoperability functions that SBCs provide, so they are an obvious NFV target, yet they also present certain challenges.
According to Walter Kenrich, the Director of Product Marketing at Sonus Networks, simply porting an application to a virtual machine, especially one as sophisticated as a SBC, doesn’t mean it will work in the cloud. “There is a lot of “myth vs reality” out there when it comes to Virtual SBC options,” says Kenrich. “Companies are obviously concerned about security in cloud communications, as well as insuring interworking and scalability - especially when an SBC is being deployed on a COTS (Common Off The Shelf) server.” The thought being that as the optimized hardware disappears, the standard hardware could have difficulty keeping up with heavy interworking and media processing requirements. However, according to Kenrich, “As the technology has been tested and improved, these areas have been addressed and effectively overcome, especially when businesses and services providers deploy orchestration software, like OpenStack, to manage their virtual communications services.” (NOTE: In a previous article we discussed some of these media processing challenges...keep your eyes open for a post updating how this is being addressed) .
Three Models for Deploying Virtual or Cloud Based Session Border Controllers
As Session Border Controller vendors like Sonus have been working to optimize their virtual SBC offerings, businesses and service providers have been busy deploying vSBCs in a variety of ways. Here are three that, according to Kenrich, have been gaining the most traction to date:
On-Premise (CPE) Virtual Session Border Controller for Enterprises
Pretty straight forward. An enterprise owns and manages their own virtual SBC in their own public, private or hybrid cloud environment. SIP trunks come in and the customer has their own orchestration built in. Using COTS servers, the enterprise deploys a virtual SBC and enables it to be managed as an application module by their orchestration software. Simple, right? I mean, if you consider setting up that kind of thing ‘pretty straightforward’.
According to Kenrich, businesses taking advantage of a solution like this are looking to retain control of their environment while lowering costs. “Having a virtual SBC in place allows enterprises that are already comfortable managing session border controllers to spin up or down additional resources as necessary to support peak loads or busy times of the year,” says Kenrich.
Virtual SBC is On-Premise, But is Managed By Service Provider
This situation is ideal for businesses that are looking to maintain control of their own cloud environment but may not have the internal expertise to manage the details of a session border controller environment. The service provider delivers all services around the SBC and can even handle the scaling up and down of capacity because they would have access to their client’s orchestration layer.
Kenrich indicated that this model is gaining traction with larger Tier One service providers. “These firms are looking to provide as much network management (via NFV) as possible for their clients,” says Kenrich. “In addition to real time communications applications like SBCs, policy routing engines (PSX) and element management systems (EMS), these service providers are even looking to handle applications like firewalls and other traditionally networking-focused capabilities”
SBCaaS - Solution Resides on Service Provider’s Cloud
In this instance, the service provider handles all aspects of delivering SBC capabilities as a service from their own cloud. Customers eliminate all hardware requirements and rely on the CSP for setup and management, software upgrades and network configuration and security for their SBC instance. “In this scenario, service providers have their own orchestration software which allows them to adapt to identified traffic spikes,” says Kenrich. “They can utilize load balancing across instances to elastically react and can even take advantage of analytics to do so dynamically and proactively.” Just like every other area of computing, expect to see more businesses providing as-a-service offerings for SBCs.
And stay tuned for a post digging into the details about how the challenge of scaling interworking and media processing on vSBCs is being addressed.