enterprise session border controllers

What is a Session Border Controller and How Does It Work

Nowadays, more and more companies opt to choose an online route that establishes a continuous and cost-effective communication system. This is mainly because of the revolutionary VoIP (Voice over Internet Protocol) technology that has become more popularly accepted in the corporate sector.

In line with this, it is of utmost importance that the security of the company’s network is protected while creating interoperability between different VoIP solutions. It’s in this scenario where the Session Border Controller (SBC) comes into the picture.

What is SBC?

SBC is a powerful device deployed in VoIP networks to establish control over telephone calls or media streaming’s signaling. It provides full control over initiating, conducting or terminating down telephone calls on a VoIP network. In layman’s terms, an SBC is like a Firewall for VoIP network that offers services like Network Address Translator (NAT) traversal which addresses the inability of a real-time session or phone call traffic.

Today, enterprise communications have made transitions from the conventional Private Branch Exchange (PBX) to VoIP. The enterprise session border controllers (E-SBCs) is designed to overcome the complex security, service quality challenges and interoperability that information technology (IT) groups experience when they implement VoIP and mobility initiatives.

Session Border Controller and How Does It Work

How Does SBS Works?

Generally, the primary duties of a session border controller can be divided into the following four sections:

  • Topology HidingSBC works right in the middle of the call path between a service provider and an IP-PBX. Once a call is initiated, it arrives at an SBC from the PBX then the SBC works by filtering out any sensitive information. This ensures that no outside intruders can gain access to the information and hack the enterprise VoIP network.
  • IP Addresses Translation

Enterprise session border controllers (E-SBCs) also translates local IP addresses of the callers into a WAN IP address of the SBC. It’s in this part where protocol normalization occurs which refers to the process an SBC manipulates call messages to follow the service provider’s protocol implementation.

  • Encryption and TranscodingWhenever necessary, SBCS can also encrypt calls and perform transcoding. An SBC will determine where to route the calls in an enterprise that is connected to several branches and service providers. It creates routing decisions based on three criteria – reachability, call cost optimization and the best quality path.
  • ClassificationJust like outgoing calls, incoming calls follow the same steps but with one additional checking which is called classification. SBC also performs a careful process of inspection on incoming calls to recognize hackers and intruders.