Session Border Controller (SBC) Software for VOIP

Session Border Controller solution is one of the widely adopted technology in modern telecom and communication sector. Asterisk Session Border Controller (SBC) as part of its WebRTC solution is already considered as an industry standard with superior functionalities and easy integration. Let us explain here various aspects of the technology in brief.

What is Session Border Controller (SBC)?

Session Border Controller is actually a device which is widely used in advanced VoIP networks to allow better signalling 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.


SBC is used to control signaling and media streams. It is responsible for setting up, conducting, and tearing down calls. SBC allows owners to control the types of call that can be placed through the networks and also overcome some of the problems caused by firewalls and NAT for VoIP calls. VoIP service providers use SBCs to allow the use of VoIP protocols from private networks with internet connections using NAT. SBCs can also perform the function of application-level gateways. Some SBCs can also allow VoIP calls to be set up between two phones using different VoIP signaling protocols (SIP, IAX2, H.323, Megaco/MGCP, etc.) as well as performing transcoding of the media stream when different codecs (G711u, G711a, G723, G726, G729, GSM, iLBC, Speex, etc.) are in use. Various SBCs are available as hardware or software solution. Various open source solutions such as Asterisk, SER, OpenSER, FreeSwitch, OpenPBX, Yate, etc. can be used as a Session Border Controller. We offer installation, configuration and support services for these open source solutions. We can implement required SBC functions in any of the open source solutions listed above.

How Session Border Controller (SBC) Works?

Session Border Controller software is generally set up in the very borderline between two different parts of a network. A majority of the Session Border Controllers come with peered service provider networks or they are installed in the demarcation line between the residential users and service provider network.

Why you need an How Session Border Controller (SBC)?

The role of SBC is to ensure optimum network service quality and hence it is also often referred as SBC communication solution. A session basically refers to the communication happening through a call between two parties and hence it is also referred as SBC telecom solution. Now thanks to SBC software solutions the simple telephony can incorporate richer experience with streaming audio and video data. While facilitating this rich telephony experience the solution remains further protected by SBC voice firewall solutions to ensure better security to the network.

Session Border Controllers offer following functionalities

  • NAT Traversal
  • They may either act as a firewall, or cooperate with existing firewall devices in the DMZ
  • Protect softswitches from signaling attacks
  • SBCs also perform topology hiding, removing internal network information from the signaling stream thus preventing internal details from being propagated
  • Eliminate bad VoIP signaling and media protocol at the network boundary
  • Providing call admission control
  • SBC reserves service provider network resources to handle calls being set up, and ensures that there is always enough bandwidth to handle emergency services calls
  • Media bridging
  • Fault tolerance
  • Policy-based call routing
  • Signaling protocol interworking (such as between H.323 and SIP, or between variants of H.323)
  • Emergency Call Handling
  • Tracking the progress of each call for the purposes of billing, and producing Call Detail Reports
  • Topology and Carrier hiding
  • DTMF inter-working (RFC2833, Inband and SIP INFO)
  • Protocol validation
  • Codec transcoding
  • Carrier tech prefix insertion / removal
  • Flexible SIP header manipulation

Session Border Controllers can be deployed in any of the following network scenarios

  • Within a provider offering VPN services to its customers
  • On the border between a provider and their customer
  • In the network core to overcome some internal topology issues
  • In the network core as a centralized codec transcoder
  • On the border between two providers with a reciprocal agreement with respect to VoIP traffic


Session Border Controller comes with an array of benefits for telecom and data streaming over a network. Let us explain here the key benefits of SBC.

  • Security: SBC helps actively protecting the network and network devices from all sorts of malicious threats and attacks like denial-of-service attack (DoS), distributed DoS, etc. It prevents the communication from being subject to fraudulent and rogue media streams. It helps protecting the signals through encryption.
  • Connectivity: SBC facilitates great connectivity through a wide array of networking techniques like NAT traversal, SIP normalization, IPv4 to IPv6 interworking, VPN connectivity, Protocol translations, etc.
  • Quality of service: SBC ensures high quality of service through prioritization of calls and data flows and functions such as traffic policing, resource allocation, rate limiting, call admission control, etc.
  • Media services: SBC helps transmitting superior media through built-in digital signal processors (DSPs).
  • Statistics and billing information: Session border controller software also comes with precise statistics and billing information.

Why We?

Asterisk is one of the most trusted and industry recognised players in latest telecom and communication solutions. Out WebRTC solution already enjoys wider adoption and usability across industry niches. Keeping pace with the latest innovations in telecom communication, we deliver state of the art solutions customised for enterprise specific needs.

We help installing, configuring and supporting session border controller open source solutions for a wide array of industry settings. We are capable to implement a whole range of SBC functions across diverse network configurations.


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