87. Tell me about the different type of networking / internetworking devices?
Answer : The different type of networking / internetworking devices are:
Repeater: Also called a regenerator, it is an electronic device that operates only at the physical layer. It receives the signal in the network before it becomes weak, regenerates the original bit pattern and puts the refreshed copy back into the link.
Bridges: These operate both in the physical and data link layers of LANs of the same type. They divide a larger network into smaller segments. They contain logic that allows them to keep the traffic for each segment separately and thus are repeaters that relay a frame only the side of the segment containing the intended recipient and control congestion.
Routers: They relay packets among multiple interconnected networks (i.e. LANs of a different type). They operate in the physical, data link and network layers. They contain software that enables them to determine which of the several possible paths is the best for a particular transmission.
Gateways: They relay packets among networks that have different protocols (e.g. between a LAN and a WAN). They accept a packet formatted for one protocol and convert it to a packet formatted for another protocol before forwarding it. They operate in all seven layers of the OSI model.
88. What are the data units at different layers of the TCP / IP protocol suite?
Answer : The data unit created at the application layer is called a message, at the transport layer the data unit created is called either a segment or a user datagram, at the network layer the data unit created, is called the datagram, at the data link layer the datagram is encapsulated into a frame and finally transmitted as signals along the transmission media.
89. What are the minimum and maximum length of the header in the TCP segment and IP datagram?
Answer : The header should have a minimum length of 20 bytes and can have a maximum length of 60 bytes.
90. What is the range of addresses in the classes of internet addresses?
Answer : The range of addresses in the classes of internet addresses are:
Class A – 0.0.0.0 – 127.255.255.255
Class B – 22.214.171.124 – 126.96.36.199
Class C – 192.0.0.0 – 188.8.131.52
Class D – 184.108.40.206 – 220.127.116.11
Class E – 240.0.0.0 – 255.255.255.255
91. What is difference between baseband and broadband transmission?
Answer : In a baseband transmission, the entire bandwidth of the cable is consumed by a single signal. In broadband transmission, signals are sent on multiple frequencies, allowing multiple signals to be sent simultaneously.
92. What is traffic shaping?
Answer : Traffic shaping (also known as packet shaping) is a computer network traffic management technique which delays some or all datagrams to bring them into compliance with the desired traffic profile.
The practice involves delaying the flow of packets that have been designated as less important or less desired than those of prioritized traffic streams. For instance, an ISP may delay P2P packets, such as those transmitted by BitTorrent networks.
93. What is multicast routing?
Answer : Multicast IP Routing protocols are used to distribute data (for example, audio/video streaming broadcasts) to multiple recipients. Using multicast, a source can send a single copy of data to a single multicast address, which is then distributed to an entire group of recipients.
In General, Sending a message to a group is called multicasting, and its routing algorithm is called multicast routing.