Unit 7 key terms
Definitions
Switches circuit- A circuit created by the phone company in reaction to signaling (the user tapping telephone keys or a modem sending in the same digits), with the telco tearing down the circuit when the user is finished.
Dedicated circuit- An electrical circuit created by a telco on behalf of a customer, with the circuit staying up all the time, dedicated for use by the one customer that ordered the circuit.
Circuit switching- The overall process by which a series of telco devices called circuit switches connect a circuit from one customer device to the other, with the devices logic taking incoming bits on one segment in the link and forwarding those bits out the matching outgoing segment, without storing bits.
Packet switching- The process of forwarding customer data in a WAN by looking at the header of the message sent into the WAN by the customer and making a per-message (per-packet) decision as to where to forward each message.
Leased line- Another term for dedicated circuit
Time-division multiplexing- A type of logic used by some networking devices, including circuit switches in the telco, in which the switch divides a faster-speed line into time channels.
Multiplexing- The opposite of demultiplex.
T-carries system- The name of the combination of different physical line standards (DS0,DS1,DS3, and others), plus circuit switches that use time-division multiplexing (TDM) features, that together allowed the phone company to create digital circuit from end to end and create leased-line services for customers.
DS0- Digital signal level 0
DS1- Digital signal 1
Frame Relay- A widely popular packet-switching technology and service that emerged in the market in the 1990’s, using permanent virtual circuit(PVC) between pairs of routers that can send frames to each other, and data-link connection identifies (DLCI) to address and identify each PVC.
Switches circuit- A circuit created by the phone company in reaction to signaling (the user tapping telephone keys or a modem sending in the same digits), with the telco tearing down the circuit when the user is finished.
Dedicated circuit- An electrical circuit created by a telco on behalf of a customer, with the circuit staying up all the time, dedicated for use by the one customer that ordered the circuit.
Circuit switching- The overall process by which a series of telco devices called circuit switches connect a circuit from one customer device to the other, with the devices logic taking incoming bits on one segment in the link and forwarding those bits out the matching outgoing segment, without storing bits.
Packet switching- The process of forwarding customer data in a WAN by looking at the header of the message sent into the WAN by the customer and making a per-message (per-packet) decision as to where to forward each message.
Leased line- Another term for dedicated circuit
Time-division multiplexing- A type of logic used by some networking devices, including circuit switches in the telco, in which the switch divides a faster-speed line into time channels.
Multiplexing- The opposite of demultiplex.
T-carries system- The name of the combination of different physical line standards (DS0,DS1,DS3, and others), plus circuit switches that use time-division multiplexing (TDM) features, that together allowed the phone company to create digital circuit from end to end and create leased-line services for customers.
DS0- Digital signal level 0
DS1- Digital signal 1
Frame Relay- A widely popular packet-switching technology and service that emerged in the market in the 1990’s, using permanent virtual circuit(PVC) between pairs of routers that can send frames to each other, and data-link connection identifies (DLCI) to address and identify each PVC.