SBC is an acronym for Session Border Controller—a network element deployed to protect SIP-based VoIP as well as an important network element in NGN/IMS networks and enterprise audio/video systems. High Availability (HA) is a network solution used to ensure that planned and unplanned outages do not disrupt service. In an HA implementation, Session Border Controllers are deployed in a pair to deliver continuous high availability for interactive communication services. The implementation of HA ensures system stability without interruption in case of an outage of service.
To ensure HA achievement, there are many strategies used in many ways. Usually, good hardware design and smart software detection are necessary to ensure system stability. The high availability of Dinstar SBC can be achieved in seven ways.
Redundancy design of the device
Active/Standby mode
Intelligent call routing
Quality of Service (QoS)
Voice quality monitoring
Signaling control & bandwidth limit
Warning Monitoring
Redundancy design of the device
The principle of redundancy is that should a component within a /system/device fail, the /system/device will continue to function because alternative paths are available for the system to operate. So, it is important to have many redundant components that would significantly improve the reliability of the /system/device.
The SBC with certain models, supports embedded design supporting an 8-core CPU Matrix.
SBC supports 1+1 power redundancy and AC/DC power supply. And the SBC adopts dual power supplies balanced load design, when one of the power supply modules is down, the other power supply module will take up to ensure the services will not be affected.
SBC supports dual network interface bonding. These two network interfaces share an IP address and MAC address. Network bonding offers performance improvements and redundancy by increasing the network throughput and bandwidth. If one interface is down or unplugged the other one will work.
Active/standby mode
In general, active/standby mode is considered as the most essential feature of the HA. HA requires one SBC device configured as the primary device, and an identical SBC device configured as the secondary device. During normal operation, the primary SBC is in an Active state, and the Secondary SBC is in a Standby state. If the primary device loses connectivity, the secondary SBC transitions to Active mode and assumes the configuration and role of the primary, including the interface IP addresses of the configured interfaces.
Dinstar SBC not only supports active/standby mode, but also supports real-time synchronization of data of two devices, BFD heartbeat detection, and detection time granularity (from 30ms to 100ms). So, when the active and standby statuses are changed, the user's service will not be affected.
Intelligent Call Routing
Intelligent call routing is closely related to HA. Intelligent call routing can increase productivity by allowing agents to be assigned to the customer so they can maximize the system resource. Dinstar SBC supports intelligent and flexible routing policies, which can support call routing by weight, time, number, priority, custom number profile, etc., so that it can provide users with reliable and efficient routing fault tolerance solutions. Dinstar SBC also supports multi-line balanced load and master/standby redundancy to improve high availability.
Quality of Service (QoS)
Quality of Service (QoS) is a critical factor for VoIP. Quality of service (QoS) is the use of mechanisms or technologies that work on a network to control traffic and ensure the performance of critical applications with limited network capacity. It enables organizations to adjust their overall network traffic by prioritizing specific high-performance applications.
QoS networking technology works by marking packets to identify service types, then configuring routers to create separate virtual queues for each application, based on their priority. As a result, bandwidth is reserved for critical applications or websites that have been assigned priority access.
SBC provides comprehensive QoS policies that can prioritize signaling, voice, and video data, guarantee transmission performance such as delay jitter, network congestion, and packet loss rate, and improve voice and video quality.
Voice quality monitoring
Voice Quality Monitoring provides the ability to look at each source IP and view a range of MOS scores, RTP flows, jitter, loss, and out of packet order. Thus, SBC allows the network administrator to have a full view of traffic as its transverses the network and adjusts the resource based on the threshold of the performance.
SBC can monitor and analyze the media voice quality of each call in real-time, including network jitter, packet loss rate, delay, and other network indicators during the call, which greatly improves the efficiency of the users and can find the problem quickly.
And for poor network conditions, SBC provides packet loss compensation, dynamic jitter buffer, silence suppression, comfortable noise generation, RTP redundancy, and other voice enhancement technologies to provide the best user experience.
List of Warning Categories
Signaling Control & Bandwidth Limit
The SBC supports traffic overload protection, which can limit the traffic of SIP trunks and automatically start the flow control function when the system reached an overload state. and SBC can automatically adjust the service quantity according to the CPU usage and ensure a certain service connection rate and the long-term stable operation of the device.
Overload Protection
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Q: What causes traffic overload?
A: Hot events are the most common trigger sources, such as Black Friday in USA, mass events, or attacks caused by negative news. A sudden surge of registration caused by data center power failure, network failure is also a common trigger source.
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Q: How does SBC prevent traffic overload?
A: SBC can sort traffics intelligently according to user level and business priority, with high overload resistance: 3 times overload, business won’t be interrupted. Functions like traffic limitation/control, dynamic blacklist, registration/call rate limiting etc. are available.
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Warning Monitoring
Warning monitoring is a necessary component of all service systems, and a perfect warning monitoring function can greatly improve the reliability and security of the system and prevent the system failure that leads to service disruption. With the help of warning monitoring, the repeat jobs of O&M staff can be greatly reduced. By setting monitoring data rules, O&M staff can control the health running status of the system at any time.
Dinstar SBC provides a wide range of monitoring capabilities. It is able to monitor the core components of the system, service status, system process, security logs, and other aspects in real-time. SBC supports threshold customization, once the set threshold value is reached, a warning can be shown in the web GUI, and you can check the current detailed warning information.
Moreover, SBC supports alerting and reporting of Syslog logs, so that maintenance staff can monitor the running situation of the device and can quickly trace the problem when an unusual warning occurs.
SBC Main Component Monitoring
List of Warning Categories
Conclusion
In general, the HA of SBC can be done in many ways with other smart tools. HA of SBC can be deployed with hardware models with different kinds of control polices. Dinstar SBC offers a very good one with solid HA performance and stability and the solution has been implemented in many user cases. If you are interested in HA solution of SBC, please drop an email at sales@dinstar.com.
