Connectivity Framework
2: Connectivity Framework
maintains predictable performance. The connectivity function addresses latency and jitter in the data exchanged between endpoints, possibly in exchange for throughput.
Throughput. Throughput is the load on the network as defined by the volume of data flow per unit of time. Bandwidth is the network capacity of a connectivity technology. In some designs, a large volume of data may be exchanged in a short time on an ongoing basis among endpoints; high throughput would be needed.
In practice, the operational settings that optimize for high throughput are not the same as those that optimize for low latency. Therefore, the connectivity function should support achieving the right balance as per the requirements of the data flow.
In industrial internet applications, particularly at the edge, low latency and jitter are generally more important to performance than throughput and bandwidth. Automation and control of real-world processes require short reaction times or tight coordination to maintain effective control. Industrial devices in the control domain do not produce large amounts of data in short periods and therefore do not require high bandwidth connectivity. Rather, the data needs to be communicated quickly and consistently( with low latency and jitter).
2.3.2 SCALABILITY
Physical things communicate using connectivity endpoints. Therefore, the connectivity function should support horizontal scaling, by which we mean the ability to accommodate an increasing number of connectivity endpoints, reaching Internet scale.
2.3.3 RELIABILITY
The needs of the application data, like strict order of data delivery and data loss rates, determine the required level of reliability for connectivity.
2.3.4 RESILIENCE
Because many IIoT systems will operate continually in a real-world environment, the connectivity function should be available( in the logical view), even when there is a temporary physical disconnection. When a broken connection is restored, data exchange should be automatically restored so that the latest updates are available to the consumers along with any relevant missed updates.
The connectivity function should support graceful failure or disconnection of endpoints, by, for example, confining the loss of data exchange only to disconnected endpoints.
2.3.5 SECURITY
Security considerations for IIoT systems are described in detail in the Industrial Internet Security Framework( IISF) 1. The chapter“ Communications and Connectivity Protection” describes the following functional building blocks: physical security of connections, communicating endpoints
1
See [ IIC-IISF2016 ] IIC: PUB: G5: V1.0: PB: 20170228- 18-