The SBC (Session Boarder Controller) is a VoIP (Voice over Internet Protocol) network element, which is generally equipped in the border of any VoIP network for security, interoperability, routing normalisation of call handing data and customer interconnection. This could be used by telecom operators, multinational companies, corporate companies for VoIP interconnections with customers or service providers or both.
The name Session Border Controller itself depicts the main functionality of the element; which is to be placed in the border to manage sessions for the core network. Any network administrator’s first concern would be the security of the network. SBC protects the network as a border element by controlling the signalling and associated media traffic in a managed way to protect the network against DOS attack or equivalent.
In addition to security, there is another major functionality of the SBC; that is, in the interconnect space, to interoperate with different network vendor elements used by suppliers or customers in terms of signalling and media. In previous days, SBCs were used to interwork with different VoIP protocols like SIP and H.323; however, H.323 is getting obsolete these days.
The SBC (Session Boarder Controller) can operate in Integrated (Standalone Non-Split) Architecture or Distributed (Split) Architecture modes. The same SBC hardware box can handle signalling and media in non-split architecture whereas, in split architecture, signalling session controller runs in a separate hardware (even it could be cloud), where media handing SBC part runs in a different hardware. For carrier level deployments, most players prefer spilt architecture since it gives flexibility to grow with demands.
The major SBC (Session Boarder Controller) vendors in the market are GENBAND, Metaswitch, Sonus, Acme Packet (Oracle), Ericsson, Huawei, ZTE, Dialogic.
SBC Operating Architecture – Integrated and Split Mode of Operation
