Session Border Controller

Session Border Controller

A Session Border Controller is a device used in select VoIP networks to exert control over the signaling and usually also the media streams involved in setting up, conducting, and tearing down calls. The SBC enforces security, quality of service and admission control mechanism over the VoIP sessions.

The Session Border Controller is often installed in a point of demarcation between one part of a network and another. Most Session Border controllers will be installed between peering service provider networks, between the enterprise network and the service provider network, or between the service provider network and residential users.

A Session Border Controller is like a Firewall for VOIP.
They are often configured as a SIP Back-To-Back User Agent (See SIP RFC).

In addition to firewall functions, they also may provide services like NAT traversal.

See: NAT and VOIP for more information and watch the video on The Anatomy of Session Border Controllers and To Couple or Decouple Routing Intelligence from SBC.

Martyn Davies of Dialogic discusses Session Border Controllers as the often misunderstood “black magic” application for VoIP networks.

Although carriers often use Session Border Controllers for signal translation and security, most do not include the hardware-based signal processing needed for media transcoding. For all-IP environments, new elements are required that can mediate signaling, transcode among different media formats, and handle basic security issues. The concept of Multimedia Border Element (MMBE) meets these needs.


Session Border Controller (SBC) offers a secure way to access the SIP trunking. offers cost-efficient SBC development services with well-integrated network and business management features with high capacity and high-performance servers. SBC solution enables carriers to integrate flexibly with vendors and new customers to intensify revenue opportunities and operational excellence. SBC software allows users to control the types of call which can be placed through the VoIP networks. It offers robust security features that prevent users from resource damage. Its built-in firewall protects users from vulnerable DDOS/DOS attacks.

Key Features for SBC Solution :

  • Topology and Carrier hiding
  • Signaling protocol inter-working (SIP, SIP-T and H.323)
  • DTMF inter-working (RFC2833, Inband and SIP INFO)
  • Protocol validation
  • Carrier tech prefix insertion / removal
  • Codec transcoding

FreeSWITCH Session border controller is the best solution to address all your VoIP issues coming from the stable of the pioneers in the VoIP arena. FreeSWITCH Session border controller is pivotal to your enterprise Internet Protocol (IP) since it offers a very high degree of security to your network, prove to be very cost-saving both in terms of installation and manpower, and provide superlative connectivity to all your users at remote locations

Session Border Controller is actually a device that is widely used in advanced VoIP networks to allow better signaling control and high-quality media streaming. It makes setting up, streaming and securing calls on VOIP networks much easier. Thanks to SBC VOIP solutions telecom companies can ensure quality of service and better security and control.

Class 4 SoftSWITCH solution that offers reliability, scalability and high performance to its users. It ensures that it delivers secure VoIP traffic and services over a multitude of IP networks across the globe. Our VoIP Softswitch has been mainly designed for routing local and long distance calls, thus the software is affordable yet advanced that meets the needs of telecom industries.

  • Yeti Opensource SBC with integrated routing subsystem and billing. Designed as a high performance and clustered wholesale platform. Yeti supports media proxying with transcoding, SIP protocol normalization, flexible call rerouting and interaction with LNP databases. Rich CDRs allow finding any protocol issues without manual work.
  • BLOX – Open Source SBC
  • CompleteSBC by Xorcom Intrusion prevention software for your CompletePBX IP-PBX
  • OpenSIPS-60,000 CPS on commodity hardware! A multi-functional, multi-purpose signaling SIP server – it can act as SIP Router/Switch, SIP Registrar, Application Server, Redirect Server, Load Balancer / Dispatcher, Back-to-Back User Agent, Presence Server, IM Server, Session Border Controller, SIP Front-End, NAT traversal Server, IP Gateway (SMS, XMPP) and platform for many other applications.
  • CloudAstrix SPE for Service Provider Edition
  • Sangoma SBCs for Enterprise and Carrier
  • SmartNode Enterprise Session Border Controllers (E-SBCs) from PATTON Electronics provides network security, assured voice quality and integration with legacy voice systems for SIP trunk deployments. Omitting costly carrier-grade features, Patton’s affordable customer-premise E-SBCs deliver essential border-control functions at price-performance levels appropriate for small-to-medium enterprises (SMEs). Branded as SmartNode Enterprise Session Border Routers (ESBRs), Patton’s E-SBC portfolio delivers proven interoperability with all major brands of softswitches and IP PBXs, making it easy for carriers and enterprises to deploy future-proof Unified Communications (UC) systems quickly and profitably today. TCP rate control-unique in the industry to Patton SBCs-provides superior voice quality by ensuring data downloads do not disrupt nor impede voice traffic. SmartNode E-SBCs offer TDM telephony interfaces, including two and four-wire POTS analog FXS and FXO as well as digital ISDN BRI and PRI interfaces. Such TDM connectivity is essential for enterprises that want to preserve legacy PBX systems while adopting SIP trunking or preserve legacy PSTN connectivity over TDM interfaces when deploying SIP trunks in hybrid mode. H.323 support in SmartNode session border controllers ensures compatible interoperability of new, state-of-the-art SIP-base unified communications platforms with earlier H.323 installations of IP-based voice networking. Full Product Listing
  • Dialogic BorderNet 3000 Session Border Controller
  • Cisco 7600 Series Session Border Controller
  • Enterprise session border controller
  • MediaCore SBC – VoIP carrier platform, that includes softswitch, billing, advanced routing, media transcoding and revenue assurance module for VoIP anti-fraud protection.
  • CSRP – Kamailio-based Class 4 SIP routing, accounting and rating platform, enabling delivery of retail SIP trunking and wholesale SIP termination & origination. Featuring high-performance LCR, on-the-fly rating, far-end NAT traversal, and fraud detection.
  • voipXess SBC – Session Border Controller for small and medium enterprises

See also

NEOX Softswitch is a cost-effective VoIP solution that enables carriers and service providers to offer a VoIP platform supporting secure and reliable Class-5 features and functionalities over a packet-based network. The solution offers carriers and service providers the ability to launch competitive new service offerings quickly and easily to increase subscriber stickiness and revenue generation.