Computer Networks — Test 4

Correct Answer: D. D. Sonet
Explanation: Frame Relays uses carriers such as SONET (for fiber-optic connections) to physically transmit data frames over a Frame Relay network. SONET is cheaper and provides better network reliability than other carriers.

Correct Answer: B. B. Data link layer
Explanation: Frame relay provides error detection using CRC in the data link layer. The transport layer then provides the error correction features if an error is detected.

Correct Answer: A. A. Data link connection identifier
Explanation: The Data Link Connection Identifier is 10-bit virtual circuit identifier. It is used to assign frames to the specified Permanent Virtual Circuits or Switched Virtual Circuits.

Correct Answer: C. C. Physical layer and data link layer
Explanation: The physical layer is guided by the protocols recognized by the ANSI and provides conversion to frames. The data link layer supports the simplified core functions specified by the OSI model like error detection.

Correct Answer: A. A. To increase the range of data link connection identifiers
Explanation: Extended address is indicated by the last bit of every address byte in the DLCI. It specifies whether the byte is the last in the addressing field. It is used to increase the range of data link connection identifiers.

Correct Answer: A. A. Frad assembles and disassembles the frames coming from other protocols
Explanation: FRAD stands for Frame Relay Assembler/Disassembler. It converts packets into frames that can be transmitted over Frame Relay Networks. It operates at the physical layer.

Correct Answer: D. D. It is a wide area network (WAN) technology that establishes virtual connection
Explanation: Frame Relay is based on Packet-Switching Technology. It is a WAN layer protocol and focuses on increasing its speed. It operates in the Physical and Data Link Layers of the OSI Model.

Correct Answer: C. C. Frad
Explanation: Frame Relay Access Device or Frame Delay Assembler/Dissembler (FRAD) is a device that converts data packets into frames that can be sent over Frame Relay network. It also converts frames from Frame Relay into data packets. Whereas FRWAN stands for Frame relay WAN, VoFR stands for Voice over Frame Relay and FRS stands for Frame Relay Switch. Each of these entities carries out tasks that are different from FRAD.

Correct Answer: B. B. False
Explanation: Frame relay supports multiple users (or multiple circuits) on the same physical line using sub-interfaces, at the same time. It also establishes a permanent switch circuit.

Correct Answer: B. B. Asynchronous time division multiplexing
Explanation: ATM uses a constant data stream consisting of transmission cells to transmit information in a fixed division of time. The packet size remains fixed.