In addition to issues related to telephony system security, some Session Border Controller – SBC applications make it an indispensable tool for corporate scenarios.
This is because the equipment allows for adopting performance improvements that directly impact the operational cost and availability of service by reducing the complexity of data traffic between branches and minimizing possible failures that could cause interruptions in communication. Learn the basics!
Transcoding
Before you learn how these SBC applications operate, you need to understand how data traffic works on IP telephony networks.
The voice that is carried over the users Internet and the public network is transmitted with high quality, which is reflected in high consumption of bandwidth and, in turn, a high cost per call. In this scenario, transcoding performs the compression / decompression of data packets, reducing the volume of data that circulates in the internal network and between the company and the carrier (or other external connections). Thus, the demand for Internet is reduced, which results in savings.
“To do this via PBX, a high performance processor is needed, which increases the cost. By delegating this function to the SBC, there is no need to invest in this aspect. In addition, of course, having dedicated equipment for this function ensures better quality of delivery and flexibility,” explains Lauro Granzotto, Khomp Commercial Consultant.
Stand-Alone Survivability (SAS)
Necessary in cases where the telephony system unifies different locations, this feature aims at better management of the separate telephone points. “Using the SBC, it is possible to design a contingency system that considerably reduces the risks of service interruptions,” he says.
When strategically distributed across the enterprise network, SBCs are able to replace the need for a local PBX benefiting from the ability to share resources. In this model, each unit (or telephone group) is connected to a switch and uses the functions it provides.
And add to that the fact that each device can establish a direct link with carriers. “Thus, if the connection to the PBX fails, each SBC has autonomy to originate and receive calls, even without all the resources coming from the exchange,” he explains.
This feature not only brings robustness to the branch, but also to the matrix, since it can use branch outbound links as a contingency for itself, thus providing the company’s entire telephony ecosystem with redundancy.
Register Authorization (RA)
This functionality, roughly speaking, is intended to authorize or deny calls made by external extensions. “When a SIP terminal requests a call to the PBX, its credential goes through an evaluation based on a prior list of authorized users — which will determine if the call can go through or not. This makes RA an excellent measure for more securely connecting the matrix to the branches,” he explains.
With the RA function, the SBC can either take control of the register authentication by querying the LDAP database on an external server, thus freeing the PBX, or delegate the authentication to the PBX. In either case, SBC hides the topology of the internal network, ensuring its security against malicious requests.
You can also perform register authentication on multiple PBXs as a redundancy feature. After a register is authorized or denied, the SBC maintains the registration status and transactions of registered users for future reference.
Want to know more about using SBC on corporate projects? Please contact our Business Consultants at Khomp or talk to your system integrator!