Hierarchical Routing — Test 1

Correct Answer: B. B. Hierarchical routing
Explanation: Unlike other routing tables, the routing tables in hierarchical routing will have entries for their neighbour within the region and entry for each region in the network. Also, this levelling in storing entries, saves the memory of the router in case of large network.

Correct Answer: C. C. Regions
Explanation: Regions are small parts of the network with dedicated number of routers and these regions can be grouped to form clusters. Clusters can be grouped to form zones, zones into groups. A network can be levelled with names until we run short of names.

Correct Answer: C. C. 15
Explanation: The routing table will have total number of 15 entries for 11 routers, which belongs to the same region. And 4 entries for the regions other than the one in which the router is present.

Correct Answer: A. A. F
Explanation: Hierarchical routing is to divide the network into tiers that are regions, clusters, zones, groups and so on. Because of this hierarchy, the router need not to have entries for every router in the network. And, it is enough to have entries for routers from the same region and each entry for; clusters, zones, groups, depending on the level of hierarchy.

Correct Answer: A. A. Levels = ln m
Explanation: A network with “ln M” levels and “e ln M” entries for each router can be treated as optimum in levelling. This was discovered by Kamoun and Kleinrock in 1979.

Correct Answer: A. A. 4; 500, 300, 600, 200
Explanation: Network has two level hierarchy and router in the first part has 3 extra entries more than the number of routers in that part. This indicates that the network has divided into 4 parts. After subtracting 500, 300 and 600 from 1600, we get 200 routers in the last part.

Correct Answer: B. B. Non-optimal
Explanation: Hierarchical routing is simple but it is not optimum. In order to achieve optimum route, every router must be aware of all the routers in the network, it is not possible in hierarchical routing.

Correct Answer: C. C. Non-optimal
Explanation: Hierarchical routing does not provide optimum paths for the packet transmission, because every router is not aware of the routes other that the core routers. And, each region may use different local routing algorithms which makes routing non-optimal.

Correct Answer: A. A. True
Explanation: A large network is divided into levels which facilitates the devices with good channel allocation. As the number of devices decreases for each part(region), the network communication will be easy in regions.