In this section:
A Session Border Controller is a special-purpose device that protects and regulates IP communications flows. As the name implies, session border controllers are deployed at network borders to control IP communications sessions. Originally conceived to protect and control VoIP networks, SBCs are now used to regulate all forms of real-time communications including VoIP, IP video, text chat and collaboration sessions..
A call leg is a single connection between the SBC and another device. A session between two devices includes a call leg between device A and the SBC, and a call leg between the SBC and device B.
A call may require a single session or it may require multiple sessions resulting from call forking, conference call, call transfer, call recording or other mechanisms. For example, a call between two registered users through a feature server consumes two sessions: one session from User A to the Feature Server and one session from the Feature Server to User B.
The total number of concurrent sessions supported on the SBC platform may be limited by different factors, including:
The operator has package of 5,000 licenses, calls are coming in and egressing the SBC with no call forking – so each ingress and egress is one session. The maximum number of active calls is 5,000.
Call With One Session
The operator has package of 5,000 licenses. Calls are coming in and getting transferred back through the SBC. Each call consists of two sessions, so the maximum number of simultaneous active calls is 2,500.
Call With Two Sessions
For multiple call transfers using SIP REFER, even though two GCIDs are created for the original and transferred call, the SBC uses only one Session license for the session.
Typically, these sessions will traverse one or more IP networks, whether on an enterprise network or multiple service provider networks. The SBC sits at the border of each network in order to control the amount and type of sessions, as well as the type of data that can be used during these sessions. In this sense the SBC is part firewall, protecting the network from malicious IP traffic, and part traffic cop, policing how much traffic can enter the network in order to prevent overloads.
The SBC is a controller, which means it controls not only whether traffic can enter the network, but where it should be sent (referred to as session routing), and what type of modifications should be made to the traffic (such as transforming a SIP message header into an H.323 message header or downgrading an HD voice call to a compatible voice codec).
The Ribbon SBC Core Portfolio is comprised of the following Session Border Controller products:
The focus of this documentation space is on the SBC Core platforms. To view SBC Edge Portfolio product documentation, see SBC Edge Documentation.
The SBC Core addresses the next-generation needs of SIP communications by delivering embedded media transcoding, robust security and advanced call routing in a high-performance, small form-factor (or virtual) device enabling service providers and enterprises to quickly and securely enhance their network by implementing services like SIP trunking, secure Unified Communications and Voice over IP (VoIP).
The SBC Core provides a reliable, scalable platform for IP interconnect to deliver security, session control, bandwidth management, advanced media services and integrated billing/reporting tools in an SBC appliance. This versatile series of SBCs are deployed as Peering SBCs, Access SBCs or Enterprise-SBCs (e-SBCs).
The SBC product family is tested for interoperability and performance against a variety of third-party products and call flow configurations in the customer networks, and includes:
Targets medium to large session count deployments (700 to 75,000). These capacities make this product particularly well suited for large enterprises and medium to large service providers.
Targets large session count deployments (up to 150,000 sessions). These capacities make this product particularly well suited for large service providers. Example deployment scenarios include:
Targets small to large session count deployments (25 to unlimited). These capacities make this product particularly well suited for small to large enterprises and service providers. SBC SWe application resides on a private or public virtualized cloud, or on a dedicated server.
S-SBC: "Signaling SBC" in a distributed SBC deployment. An SBC must be instantiated with the Signaling personality to behave as an S-SBC.
You can configure the S-SBC behind the SIP-aware front-end Load-Balancer (SLB). Refer to SIP-Aware Front-End Load Balancer for details.
The SBC CNe is a fully containerized cloud native SBC, and offers all the benefits of cloud native applications like faster time to market, higher scalability, simpler management, cost reduction, use of automation and DevOps practices. It includes feature parity with existing hardware or software based Ribbon SBCs.