Unit 1 Assignment

Unit 1 Assignment

(1.4, pg. 29) What shortcomings of circuit switching is packet switching designed to overcome?

Packet switching corrects some issues with circuit switching, such as line efficiency, data rate conversion, waiting instead of rejecting traffic flow, and the use of priorities is now available. The line efficiency is better because more data can be sent because packet switching sends small bursts of data and then allows others to send over the same connection. Data rates do not have match exactly like in circuit switching. Traffic is sent and put in queue if the line is busy instead of being rejected. Priority can be assigned to the packets to allow them to pass through a congested link first and experience less delay.

(1.7, pg. 29) What conditions influence the routing decision in a packet-switching network?

Failure and congestion affect routing decisions in a packet-switching network. If a node or trunk fails it can no longer be used and data must find a different route to get to the destination. When congestion exists on the network, traffic can still pass but it will be delayed significantly. It is best to not use the congested trunks to bypass the delay.

(2.5, pg. 60) What is a protocol architecture?

A protocol architecture is used to break a task up into subtasks. Each layer of the protocol architecture complete their individual sub task then passes it onto the next layer. This breakup of these tasks into modules allows changes to be made in one without affecting the entire process. This allows changes to occur with less disruption to the service.

(2.7, pg. 60) What are some advantages to layering as seen in the TCP/IP architecture?

Layering in the architecture allows for standardization amongst vendors and software programs. Since the entire process is very complex, making smaller more manageable pieces is more beneficial for users and vendors. Creating subtasks also allows changes to be made without having to redesign the entire process.

(3.1, pg. 95) Give some reasons for using fragmentation and reassembly.

Fragmentation is necessary to allow traffic to pass between networks with different maximum packet sizes since a uniform packet size is unrealistic amongst all networks. Packets may be fragmented multiple times throughout the path to the destination. Once fragmentation has occurred it must be reassembled for the data to make sense. Reassembly occurs normally at the destination.

(3.8, pg. 95) What is the purpose of each of the IPv6 header types?

Hop-by-hop header identifies when special options exist