Sonet — Test 1

Correct Answer: A. A. Synchronous optical network
Explanation: SONET stands for synchronous optical network. Frame relay uses SONET to physically transmit data frames over a Frame Relay network as SONET is cheaper and provides better network reliability than other carriers.

Correct Answer: A. A. 51.84 mbps
Explanation: STS-1 level provides the data rate of 51.84 Mbps, STS-3 provides a data rate of 155.52 Mbps, STS-12 provides a data rate of 622.080 Mbps and STS-48 provides a data rate of 2488.320 Mbps.

Correct Answer: A. A. From its optical source to its optical destination
Explanation: The path layer in SONET is responsible for the movement signal from the optical source to the optical destination. It is ideally expected to find the shortest and the most reliable path to the destination.

Correct Answer: C. C. Physical layer
Explanation: The photonic layer in SONET is like the physical layer of the OSI model. It is the lowest layer among the four layers of SONET namely the photonic, the section, the line, and the path layers.

Correct Answer: C. C. 8000 frames
Explanation: SONET defines the electrical signal as STS-N (Synchronous Transport Signal Level-N) and the optical signal as OC-N (Optical Carrier Level-N). The building block of SONET is the STS-1/OC-1 signal, which is based on an 8-kHz frame rate and operates at 51.84 Mbps.

Correct Answer: D. D. Sts-1 provides the data rate of 622.080mbps
Explanation: In SONET, STS-N stands for Synchronous Transport Signal Level-N. STS-1 level provides the data rate of 51.84 Mbps, and STS-12 provides a data rate of 622.080 Mbps.

Correct Answer: C. C. Both point-to-point and multi-point
Explanation: Synchronous Optical Network (SONET) is basically an optical fiber point-to-point or ring network backbone that provides a way to accommodate additional capacity as the needs of the organization increase to multipoint networks.

Correct Answer: A. A. Line layer
Explanation: The Line layer in SONET operates like the data link layer in the OSI model and it is responsible for the movement of signal across a physical line. The Synchronous Transport Signal Mux/Demux and Add/Drop Mux provide the Line layer functions.

Correct Answer: B. B. Two rings
Explanation: One ring is used as the working ring and other as the protection ring in which each node is connected to its respective adjacent nodes by two fibers, one to transmit, and one to receive.

Correct Answer: C. C. Sdh stands for synchronous digital hierarchy and is a similar standard to sonet developed by itu-t
Explanation: SDH is a standard that allows low bit rates to be combined into high-rate data streams and as it is synchronous, each individual bit stream can be embedded into and extracted from high-rate data streams easily.