Chapter 4, Problem R1RQ

Let’s review some of the terminology used in this textbook. Recall that the name of a transport-layer packet is segment and that the name of a link-layer packet is frame. What is the name of a network-layer packet? Recall that both routers and link-layer switches are called packet switches. What is the fundamental difference between a router and link-layer switch?

Program Plan Intro

Link Layer:

Link layer is the aggregation of procedures and protocols used in a link to share the data between the nodes. It includes mainly three functions namely, detection of transmission errors, regulation of data flow and provides well-structured interface.

Explanation of Solution

Description of network layer packet:

• Network layer is provides the path in which the data packets are transferred from the source to the destination.
• It also helps in converting the logical or Internet Protocol (IP) address to physical or Media Access Control (MAC) address.
• The packet related to network layer can be termed as datagram.

Differences between router and link layer switch:

Router	Link layer switch
The router process in the internet protocol is done by network layer, link layer and physical layer. In latest routers, transport layer is also included.	The link layer switch process is done using data link layer and physical layer.
A router transmits the data packet using IP layer address.	A link layer transmits the data frames using MAC layer address.
In router, the data in transmitted in the form of packets or data packets.	In link layer switch, the data is transmitted in the form of frames or data frames.
It is used in Local Area Network (LAN), Wide Area Network (WAN) and Metropolitan Area Network (MAN).	It is used in LANs only.
In this, the data is transmitted in full duplex mode.	In this, the data is transmitted in both full duplex and half duplex modes.