What is a Session Border Controller?
A Session Border Controller (SBC) plays a major role in securing and controlling real-time communications, specifically in Voice over Internet Protocol (VoIP) and video conferencing environments. They act as middle-men, admitting or rejecting endpoint devices to a session, and direct communications between these devices and any intermediaries on the network. This functionality is essential for ensuring that communications are secure and properly managed.
One of the key functions of a Session Border Controller is to protect and secure real-time communications from various threats, including spoofing, distributed denial-of-service (DDoS) attacks, and toll fraud. SBCs hide network topology by acting as a back-to-back user agent for a network. This makes it harder for malicious users to reach vulnerable parts of your network. In addition, SBCs encrypt signaling and media, ensuring that communications are secure and protected from eavesdropping or tampering.
A Session Border Controller also plays an important role in enabling call admission control and dynamic blocking of rogue endpoints. This helps prevent telephony DoS attacks and toll fraud by ensuring that only authorized devices are allowed to participate in a session. Furthermore, SBCs can transcode and change codecs as media sessions pass through them, ensuring compatibility between different endpoints and allowing for efficient use of network resources.
Software Session Border Controller
In recent years, the rise of virtual SBCs has brought additional benefits to the table. These virtual SBCs are implemented entirely in software and can be deployed on commercial, off-the-shelf servers. This allows for deployment on a single server, which in turn lowers operating costs. Virtual SBCs also run on typically cheaper hardware than physical SBCs and can be quickly scaled up or down to meet demand. Additionally, the emergence of cloud-native SBCs offers features such as auto-scaling, efficient resource allocation, and subscription-based licensing models, further enhancing their appeal and utility in modern communication networks.
Features
- Securing and Controlling Real-Time Communications
- Admits or rejects end devices to a session.
- Enables video conferences connecting multiple devices
- Directs communications between end devices and any intermediate devices on the network.
- Facilitates VoIP calls between two phones.
- SIP Trunking
- Guards against spoofing, DDoS attacks, and toll fraud
- Hides network topology, making it harder to reach vulnerable parts of the network.
- Encrypts signaling and media for secure transmission.
- Utilizes IDS/IPS and firewalls for attack prevention.
- Enables call admission control and dynamic blocking of rogue endpoints to prevent telephony DoS and toll fraud.
- Software SBC
- Implemented entirely in software for deployment on commercial, off-the-shelf servers.
- Allows deployment on a single server, lowering operating costs.
- Runs on typically cheaper hardware than physical SBCs.
- Can be quickly scaled up or down to meet demand.
- Cloud-Based SBC
- Auto-scaling capabilities for efficient resource allocation.
- Supports subscription-based licensing models.
- Enables efficient and reliable resource allocation.
Related References
More Information
- Transport Layer Security (TLS)
- Voice over IP (VoIP)
- Codecs Used in Voice over IP Technologies
- Nat/Firewall Software
- SIP Trunking
- Session Initiation Protocol (SIP)
- Real-Time Transport Protocol (RTP)
