Why is constant bit rate telephone considered circuit switching technology?

Constant bit rate telephone is considered circuit switching technology primarily because it establishes a dedicated communication path or circuit between two endpoints for the duration of the call. This means that once a connection is made, it allows for a continuous and consistent flow of data, just like a traditional phone line.

This dedicated circuit ensures that a fixed amount of bandwidth is allocated for the conversation, leading to a predictable quality of service with minimal latency or jitter. The circuit remains open and exclusively used by the two parties, which is a hallmark of circuit switching. Each call, therefore, has its own path through the network, enabling reliable communication without interruptions that can arise in other transmission methods.

Understanding how this contrasts with other technologies, such as packet switching, is crucial. Packet switching breaks data into packets that can be routed independently across a shared network, where circuits are not dedicated. Hence, constant bit rate telephone, by maintaining a fixed and dedicated connection throughout the call, exemplifies the principles of circuit-switched technology.