Optical Communication — Test 2

Correct Answer: D. D. Disability to handle burst traffic
Explanation: In traffic conditions, data is sent in the form of bursts of different lengths. Thus, the resources cannot be readily assigned. The OCS cannot efficiently handle burst traffic.

Correct Answer: C. C. Optical circuit-switched
Explanation: In an optical packet-switched network, data is transported in the optical domain. This is done without intermediate optic-electrical conversions. Optical electro-conversions takes place in circuit-switched networks.

Correct Answer: A. A. Four
Explanation: An optical packet switch performs four basic functions. These include routing, forwarding, switching and buffering.

Correct Answer: C. C. Buffering
Explanation: Switching involves directing the packets. Routing provides network connectivity while forwarding and reversing involves defining a packet. Buffering usually provides data storage for packets.

Correct Answer: C. C. Guard band
Explanation: A packet consists of a header and the payload. The label points to an entry in the lookup table. A guard band is usually included to ensure the data is not overwritten.

Correct Answer: A. A. False
Explanation: Labeling suggests where the packet should be directed. Routing routes the data in the given direction. Thus, labeling technique is efficient and faster than the routing technique.

Correct Answer: B. B. Multiprotocol label switching
Explanation: Multiprotocol label switching (MPLS) was first proposed by CISCO systems. Earlier, it was called as tag switching. MPLS uses labels to forward, switch, designate the traffic.

Correct Answer: A. A. True
Explanation: MPLS is flexible in the current protocol landscape. It supports Ethernet, frame relay as a data link layer but is independent of layer 2 and 3 in the OSI model.

Correct Answer: C. C. VPN’s
Explanation: One of the important services provided by MPLS is IP virtual private networks. All others are provided by packet switched networks. These VPN’s provide a secure, dedicated wide area network (WAN) in order to connect the offices all over the world.

Correct Answer: D. D. Burst header packet
Explanation: Burst header cell consists of information regarding switching and destination address. It works with the use of transmission units called as data bursts.