What’s a session border controller?
You don’t have to be a call centre expert to appreciate the staggering number of ways that your customers now want to engage. From voice calls to web chat, text messages to video conferencing, communicating in real-time has become an omnichannel affair. As VoIP adoption becomes more commonplace, your enterprise needs to manage all of that communication data as securely and effectively as possible. And that’s the job of a session border controller (SBC).
As the name would suggest, an SBC sits on the border of your own network, either at the network edge or at carrier interconnects. The SBC sits between your private network and any public network during real-time communication. It protects and regulates IP communication flows to ensure things go smoothly. That can happen in a number of ways.
How an SBC improves security, service and support
It makes SIP trunking easier
The session initiation protocol (SIP) is the industry standard for controlling VoIP, video, and text message communication sessions. In a cloud PBX system, it allows the network to establish, maintain and terminate these sessions between two or more parties.
SIP trunking refers to the virtual link between your PBX and the wider standard phone network (also known as the PSTN). It’s how the data generated by your chat/call/video is converted and communicated to other users through the public network.
A session border controller provides a layer of security to this communication by acting as a kind of firewall. An SBC makes it more difficult for bad actors to access any network vulnerabilities. It helps to safely route and connect SIP calls, as well as acting as a termination point for the SIP trunk itself.
Although the PSTN is due to close completely by 2025, the requirement for SIP trunking will remain very much at the fore for companies.
It secures your network against cyber threats
When we say SBCs can act as a firewall, they can actually perform a number of different security functions. They can be deployed to detect and prevent Denial of Service (DoS) or Distributed Denial of Service (DDoS) attacks before they affect the network.
Similarly, they help reduce the threat of telephony DoD by enabling features such as call admission control. This prevents the over-subscription of VoIP networks in real-time. Plus, an SBC can facilitate dynamic blacklisting of rogue endpoints. That means you can discover and isolate compromised devices or systems quickly.
SBCs can hide your internal IP network topology from cybercriminals, which reduces their chances of finding or exploiting any weaknesses.
And a session border controller prevents the communications data from interception or tampering by encrypting both the signalling and the media.
It smooths inter-network connections and communication
There is another consequence of the glut of communication channels that your enterprise has to manage. And that is the number of different networks and protocols that your business must handle in real-time.
Just think of the variety of IP applications that now communicate across the internet in your business. Unified communications (UC) require different streaming formats, audio codecs, messages and media. A session border controller provides the necessary interworking between incompatible protocols and SIP variants.
In essence, it acts as a translator in real-time. It makes sure that each party is fully supported throughout the data exchange session. So there’s no loss of features on either side.
It simplifies session gatekeeping and routing
We’ve mentioned the benefits of this kind of controller when it comes to protecting VoIP networks from call over-subscription. But an SBC can also perform session admission control. This, in turn, provides the same type of traffic management on the network as a whole.
By acting as the gatekeeper, the SBC can determine who has permission to access the SIP network. This reduces the risk of bad actors accessing the system and ensures that the network doesn’t get overloaded.
Where the SIP network is fairly large, several SBCs can be used at multiple borders. But rather than individually configure each controller, it is possible to dynamically manage them centrally with a single set of routing and policy rules. This solution can save both time and money.
Impact on customer and employee experiences
When used as part of a contact centre as a service (CCaaS), an SBC improves your quality of service in a number of ways. Because it can analyse traffic and optimise routing, this helps to significantly increase data speeds and the quality of your voice calls.
And when things get busy, it can also prioritise and redirect sessions to maintain performance.
We’ve also touched on the additional layers of security this adds to your IP network. Not only can they specify and encrypt traffic, but they can add advanced measures such as rate-limiting to prevent DDoS and fraud.
And just as importantly, SBCs improve both the reliability and security of your communications with customers. They have the ability to detect and normalise different SIP dialects. This means your agents can enjoy uninterrupted, high quality and seamless calls across multiple devices and in real-time.
Learn more about contact centre as a service
For more information about choosing the right CCaaS provider and the benefits of cloud-based contact centres, check out our resources below:
- Whitepaper: The best contact centre statistics for your business case.
- Infographic: On-premises vs cloud contact centre.
- Brand Battle: RingCentral vs 8×8.
- Brand Battle: 3CX vs Citrix.
- Case Study: Ashley Helme Associates.