Network Protocols — Test 1

Correct Answer: D. D. L2cap
Explanation: L2CAP is Logical Link, Control Adaptation Protocol Layer. The logical unit link control adaptation protocol is equivalent to logical link control sub layer of LAN. The ACL link uses L2CAP for data exchange. The various function of L2CAP is segmentation and reassembly, multiplexing and quality of service.

Correct Answer: A. A. Communication
Explanation: A protocol is a set of rules that governs the communications between computers on a network. These rules include guidelines that regulate the characteristics of a network including access method, allowed physical topologies, types of cabling, and speed of data transfer.

Correct Answer: B. B. Network of networks
Explanation: Internet is a massive network of networks, a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the Internet.

Correct Answer: D. D. Data link layer
Explanation: The checksum is used in the Internet by several protocols although not at the data link layer. Like linear and cyclic codes, the checksum is based on the concept of redundancy. Several protocols still use the checksum for error detection.

Correct Answer: A. A. Discarded
Explanation: A 4 bit field defines the version of IPv4 protocol. This field tells the software running in the processing machine that the datagram has the format of version 4. If the machine is using some other version of IPv4, the datagram is discarded rather than interpreted incorrectly.

Correct Answer: D. D. Protocol
Explanation: ‘The network layer at the source is responsible for creating a packet from the data coming from another’ protocol (such as a transport layer protocol or a routing protocol). The network layer is responsible for checking its routing table to find the routing information.

Correct Answer: C. C. 20 to 60 bytes
Explanation: IP header length is a minimum of 20 bytes and a maximum of 60 bytes. The minimum value for this field is 5, which is a length of 5×32 = 160 bits = 20 bytes. Being a 4-bit value, the maximum length is 15 words (15×32 bits) or 480 bits = 60 bytes.

Correct Answer: B. B. Variable length
Explanation: ‘IPv4 is a connectionless protocol used for packet switched networks. It operates on best effort delivery model, in which neither delivery is guaranteed, nor proper sequencing or avoidance of duplicate delivery is assured. The size of the datagram header can be of variable length from 20 bytes to 60 bytes.’

Correct Answer: D. D. Precedence bits
Explanation: The 8-bit ToS (type of service) in IPv4 uses 3 bits for IP Precedence, 4 bits for ToS with the last bit not being used. The 4-bit ToS field, although defined, has never been used.

Correct Answer: B. B. Tcp
Explanation: ‘In computer networking, the link layer is the lowest layer in the Internet Protocol Suite. It is commonly known as TCP/IP, the networking architecture of the Internet. It is described in RFC 1122 and RFC 1123.’