Which WAN switching technology is used by Asynchronous Transfer Mode (ATM)?

A.
cell-switching

B.
virtual switching

C.
circuit-switching

D.
packet switching

Explanation:
Cell switching is used by Asynchronous Transfer Mode (ATM). ATM is an International Telecommunication
Union-Telecommunications (ITU-T) standard for transmission of data, voice, or video traffic using a fixed size
frame of 53 bytes, known as cells. Out of these 53 bytes, the initial five bytes are header information and the
remaining 48 bytes are the payload.
The term virtual switching is incorrect because it is not a valid WAN switching technology.
Circuit switching dynamically establishes a virtual connection between a source and destination. The virtual
connection cannot be used by other callers unless the circuit is released. Circuit switching is the most common
technique used with the Public Switched Telephone Network (PSTN) to make phone calls. The dedicated circuit
is temporarily established for the duration of the call between caller and receiver. Once the caller or receiver
hangs up the phone, the circuit is released and is made available to other users.
Packet switching is also used for data transfer but not in an ATM network. With packet switching, the data is
broken into labeled packets and is transmitted using packet-switching networks. The Internet and LAN
communications use packet switching.
Objective:
WAN Technologies
Sub-Objective:
Describe WAN access connectivity options

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