It is obvious that a router or a switch needs to do searching to find information in the corresponding table. The searching in a routing table for a datagram network is based on the destination address; the searching in a switching table in a virtual circuit network is based on the combination of incoming port and incoming VCI. Explain the reason and define how these tables must be ordered (sorted) based on these values.

It is obvious that a router or a switch needs to do searching to find information in the corresponding table. The searching in a routing table for a datagram network is based on the destination address; the searching in a switching table in a virtual circuit network is based on the combination of incoming port and incoming VCI. Explain the reason and define how these tables must be ordered (sorted) based on these values.

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

The minimum number of columns in a datagram network is two; the minimumnumber of columns in a virtual-circuit network is four. Can you explain thereason? Is the difference related to the type of addresses carried in the packetsof each network?
The minimum number of columns in a datagram network is two; the minimum number of columns in a virtual-circuit network is four. Can you explain the reason? Is the difference related to the type of addresses carried in the packets of each network?
We mentioned that two types of networks, datagram and virtual-circuit, need a routing or switching table to find the output port from which the information belonging to a destination should be sent out, but a circuit-switched network has no need for such a table. Give the reason for this difference.
An entry in the switching table of a virtual-circuit network is normally created during the setup phase and deleted during the teardown phase. In other words, the entries in this type of network reflect the current connections, the activity in the network. In contrast, the entries in a routing table of a datagram network do not depend on the current connections; they show the configuration of the network and how any packet should be routed to a final destination. The entries may remain the same even if there is no activity in the network. The routing tables, however, are updated if there are changes in the network. Can you explain the reason for these two different characteristics? Can we say that a virtual-circuit is a connection oriented network and a datagram network is a connectionless network because of the above characteristics?
Consider the switch shown below. Suppose that all datagrams have the same fixed length, that the switch operates in a slotted, synchronous manner, and that in one time slot a datagram can be transferred from an input port to an output port. The switch fabric is a crossbar so that at most one datagram can be transferred to a given output port in a time slot, but different output ports can receive datagrams from different input ports in a single time slot. What is the minimal number of time slots needed to transfer the packets shown from input ports to their output ports, assuming any input queue scheduling order you want (i.e., it need not have HOL blocking)? What is the largest number of slots needed, assuming the worst-case scheduling order you can devise, assuming that a non-empty input queue is never idle? Output port X → Switch fabric Output port Y Output port Z →
As another example, consider a circuit-switched network that connects computers in two remote offices of a private company. The offices are connected using a T-1 line leased from a communication service provider. There are two 4 × 8 (4 inputs and 8 outputs) switches in this network. For each switch, four output ports are folded into the input ports to allow communication between computers in the same office. Four other output ports allow communication between the two offices. Figure shows the situation
Problem 3 Consider the problem of deciding whether to implement a virtual- circuit or a datagram network. Assume a network protocol that allows the system to operate as either a virtual circuit network or a datagram network. That is, its packet header format is specified such that it incorporates both a VCI (Virtual Circuit Identifier) and an arbitrary source/destination addresses. When operating as a virtual circuit, it requires a 4-byte header. When operating as a datagram network, it requires a 40-byte header. Assume that there are 4 hops from source to destination, and that a set up or tear down request packet is 80 bytes (including the header). The total message length is 4096 bytes, the data rate is 9600 bps on all links and the packet size is 256 bytes (including the header). i) If we operate in the datagram mode, how long does it take for the first packet to reach the destination? If we operate in virtual-circuit mode, how long does it take for the first packet to reach the…
4. Consider the switch shown below. Suppose that all datagrams have the same fixed length, that the switch operates in a slotted, synchronous manner, and that in one time slot a datagram can be transferred from an input port to an output port. The switch fabric is a crossbar so that at most one datagram can be transferred to a given output port in a time slot, but different output ports can receive datagrams from different input ports in a single time slot. What is the minimal number of time slots needed to transfer the packets shown from input ports to their output ports, assuming any input queue scheduling order you want (i.e., it need not have HOL blocking)? What is the largest number of slots needed, assuming the worst-case scheduling order you can devise, assuming that a non-empty input queue is never idle? ZY Switch fabric Output port X Output port Y Output port Z
P4. Consider the switch shown below. Suppose that all datagrams have the same fixed length, that the switch operates in a slotted, synchronous manner, and that in one time slot a datagram can be transferred from an input port to an output port. The switch fabric is a crossbar so that at most one datagram can be transferred to a given output port in a time slot, but different output ports can receive datagrams from different input ports in a single time slot. What is the minimal number of time slots needed to transfer the packets shown from input ports to their output ports, assuming any input queue scheduling order you want (i.e., it need not have HOL blocking)? What is the largest number of slots needed, assuming the worst-case scheduling order you can devise, assuming that a non-empty input queue is never idle? Switch fabric Output port X Output port Y Output port Z
Provide the steps of Distance Vector Routing for the following routers. You can start with R1 and continue to find the routing tables of R1 and R2 routers in the diagram after examining the input from R2 and R4 for R1 and examining the input from R1 and R3 for R2. Note: Correct and detailed answer will be Upvoted else downvoted. Thank you!
Explain why collision is an issue in a random-access protocol but not in reservation or channel partitioning protocols.
It is possible to describe an isochronous connection and a synchronous connection by comparing and contrasting these two kinds of connections.