PBX private branch exchange is the base hardware required for circuit switched network in old times and new aged network requires switch to pass the electronic signals for communication. Circuit switched network is most efficient in carrying voice traffic with least mobility.
Whereas the packet switched networks are those which distribute the message into packets and packets are delivered to destination with headers of source and destination address. Packets are reassembled at destination to complete the message. Packet switched network for long used in data communication. Computer servers are the base hardware required in circuit switched network. The benefit of maximum reach ability of phone lines with circuit switched network is compensated with efficiency and low cost by packet switched networks.
Due to various constraints and benefits circuit and packet switched networks are used in pair.
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