Cisco Certified Network Associate (CCNA) Practice Exam

In which WAN/LAN concept do sending and receiving devices make forwarding decisions based on the header of the PDU rather than a fixed path?

1. Circuit switching

2. Packet switching

3. Frame switching

4. Static switching

The correct answer is: Packet switching

The correct answer is packet switching. In this concept, both sending and receiving devices utilize the header information of the Protocol Data Unit (PDU) to make forwarding decisions for each packet as it travels through the network. This allows for a more dynamic approach to data transmission, where packets can take different paths based on current network conditions, congestion, or routing decisions made at each hop. Packet switching effectively maximizes network resource utilization since the same network paths can be shared by multiple communication sessions, making it well-suited for data traffic such as internet communications. The ability to route packets based on their headers, which contain addressing and control information, enables flexibility and efficiency in managing data flows across the network. In contrast, circuit switching establishes a dedicated communication path between two devices for the duration of the session, which is not based on PDU headers. Frame switching and static switching do not offer the same level of dynamic path selection as packet switching does.