Week 10 Tutorial Questions – Solutions Chapter 20 ed 4: Network Layer (Internet Protocol) Solutions – ECTE182 – Internet Technology 1 - Spring Session 2007/2012 Review Questions 1- What is the difference between the delivery of a frame in the data link layer and the delivery of a packet in the network layer? The delivery of a frame in the data link layer is node-to-node. The delivery of a packet at the network layer is host-to-host.
2- What is the difference between connectionless and connection-oriented services? Which type of the service is provided by IPv4? Which type of the service is provided by IPv6? Communication at the network layer in the Internet is connectionless. Why? In a connectionless service, there are no setup and teardown phases. Each packet is independent from every other packet. Communication has only one phase: data transfer. In connection-oriented service, a virtual connection is established between the sender and the receiver before transferring data. Communication has three phases: setup, data transfer, and teardown. IPv4 provides a connectionless service; IPv6 normally provides a connectionless service, but it can provide a connectionoriented service if flow label field is used.
3- Define fragmentation and explain why the IPv4 and IPv6 protocols need to fragment some packets. Is there any difference between two protocols in this matter? Each data link layer protocol has a limit on the size of the packet it can carry. When a datagram is encapsulated in a frame, the total size of the datagram must be less than this limit. Otherwise, the datagram must be fragmented. IPv4 allows fragmentation at the host and any router; IPv6 allows fragmentation only at the host.
School of Electrical, Computer and Telecommunication Engineering – P Doulai/P Vial - Spring Session 2007/12
ECTE182 – Internet Technology 1 – Tutorial Questions – Network Layer