What is Session Border Controller (SBC)? VoIP Internet Explained

Modern voice, video and multimedia communications systems utilize Internet Protocol (IP) networks for transferring communication information. Although there are numerous advantages associated with the transition from conventional telephone networks to Voice over IP systems, there is also a need to secure the communication channels in terms of new digital threats. 

This is where a specific technology becomes very important to ensure the security, management, and optimization of internet calls. So, what is session border controller technology, and why does it become very important in the modern environment?

Basics of Session Border Controller

Session Border Controller is a special hardware device or software solution that is situated on the border of different IP communication networks. 

It may be regarded as a special firewall designed to work with real-time traffic. Traditional firewalls provide security and protection for data packets such as e-mails and web traffic. 

However, SBC manages and controls real-time communication sessions. This technology is responsible for controlling the flow of signaling protocols (such as SIP – Session Initiation Protocol) and media streams (audio/video).

Key Features of a Session Border Controller

To understand the Session Border Controller technology, we should examine the key features performed by it every second on the edge of a network:

• Protection from Cyber Attacks and Toll Fraud

  SBCs protect networks from Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks; protect from toll fraud; and secure against any unauthorized eavesdropping and encryption of signaling and media streams.

• Interworking of Protocols

  Each manufacturer may slightly vary the implementation of the communication protocols. SBCs standardize these implementations, enabling intercommunication of equipment from different vendors.

• Media Codecs Translation

  When two endpoints speak different voice codecs (for example, G.711 and G.729), the SBC translates the media stream on-the-fly to make both sides able to understand each other.

• Quality of Service Control

  SBCs enforce the call admission control policies, prioritize media flows, and allocate bandwidth in order to avoid packet loss, jitter, and dropped calls.

• Session Routing

  They route calls to the appropriate routes in order to save resources and avoid congestion.

Types of Session Border Controllers

To accommodate varying operating scenarios, SBCs are designed to work in a range of sizes and modes:

• Enterprise SBCs (E-SBCs)

  A network’s edge is where an E-SBC is deployed to act as the dividing line between the office network and the outside world of SIP trunking service providers.

• Service Provider SBCs

  SBCs that operate at carrier-grade capacity are used by telecommunication providers in core, access, and interconnect borders of subscriber networks to manage millions of concurrent sessions.

• Virtual and Cloud-native SBCs

  With evolving needs for modern infrastructures, SBCs can now be delivered in a software version that runs on virtual machines or clouds. This helps with the NFV requirement.

Main Business Applications

There are various uses of SBCs by businesses in real-time applications, including:

• SIP Trunking Adoption

  Connecting enterprise Private Branch Exchange (PBX) phone systems to external ITSP networks securely, ensuring seamless voice traffic transmission, protocol normalization, robust network encryption, and reduced recurring communication expenses.

• Remote and Mobile Workforce Support

  Extending secure internal VoIP extensions to home office teleworkers and mobile apps over public internet connections, safeguarding remote endpoint registrations while maintaining crystal-clear voice quality across all distributed user locations.

• IP Contact Center Routing

  Managing high volumes of customer interactions, distributed call queuing, and voice traffic across global support centers, optimizing agent allocation efficiency, reducing peak-hour waiting times, and maintaining high continuous operational uptime.

• Unified Communications Integration

  Merging distinct voice, video conferencing, and messaging tools into a single, cohesive communications ecosystem, eliminating platform operational silos, simplifying cross-departmental collaboration workflows, and dramatically boosting overall workforce productivity.

Also Read: How Good Cybersecurity Strategies Are Shaped by Threat Intelligence Research

Conclusion

Understanding the Session Border Controller functionality helps one realize why the session border controller is still a vital investment for any business using internet communications. As a gatekeeper, facilitator, and traffic controller, SBC ensures daily secure, quality, and reliable voice/video sessions.

Frequently Asked Questions (FAQs)