Session Border Controller for VoIP Service Provider – Why they need it and how it can be indispensable

Session Border Controller

VoIP service providers may assume that a class 4 softswitch and class 5 softswitch are sufficient for their operations. In normal circumstances these softswitches do carry out majority of operations but then there are glitches.


Voice traffic travels over IP networks and is susceptible to eavesdropping and ports can be tunneled into, even bypassing standard firewalls. Services and security are compromised and a service provider may well lose a client. Introduction of session border controller in the network leads to topology hiding, protocol hiding and an extra layer of firewall security.

Communication issues

VoIP service providers need to provide local as well as international call services across diverse geographic locations with their own set of network and telecom protocols. Network address translation can become a hindrance in SIP communication. Business customers do not like glitches in calls and are likely to switch services. SBC solution for VoIP takes care of this issue and customers never face an issue.


The world of audio and video communications is a hodge-podge of various media protocols at originating and receiving ends. It can be a frustrating experience. Blame is placed on the VoIP service provider for poor call quality and he can lose business. Inclusion of software SBC can circumvent all such protocol related issues. SBCs handle media protocols and take care of transcoding from H.323 to SIP and vice versa for these and other codecs like G.729 and G.711 as well as from IPV4 to IPV6.

Costs and profitability

VoIP is a competitive business and service providers can optimize returns by least cost routing across best quality networks, a task admirably handled by the SBC solution in the VoIP network. In addition, SBCs can include billing, tracking of calls, recordings and analysis to further improve business process and derive insightful intelligence to optimize services. Customer retention and satisfaction improves considerably due to a seamless experience.

The carrier with whom the VoIP service provider ties up may have their own SBC but that is not sufficient. Ideally, SBCs should be operational both at the receiving and the terminating end for a seamless call experience. Besides, SBCs from the right vendors offer more than just technical aspects; they also include management and accounting functions like billing/tax and calls made in addition to attempts at fraud.

It all depends on the SBC solution. Proprietary hardware SBC can be expensive as well as impossible to upgrade. The solution is software based custom SBC tailored to suit a VoIP service provider’s specific business model and his region of operation.