Chapter 5 Network Layers Questions 3, 5, 8
Chapter 5: Questions 3,4, and 8
9/29/2012
3. What are the parts of TCP/IP and what do they do? Who is the primary user of TCP/IP?
TCP/IP has two parts. TCP is the transport layer protocol that links the application layer to the network layer. It performs segmenting: breaking the data into smaller PDUs called segments, numbering them, ensuring each segment is reliably delivered, and putting them in the proper order at the destination. IP is the network layer protocol and performs addressing and routing. IP software is used at each of the intervening computers through which the message passes; it is IP that routes the message to the final destination. The TCP software needs to be active only at the sender and the receiver, because TCP is involved only when data comes from or goes to the application layer. TCP/IP is the transport/network layer protocol used on the Internet. It is the world’s most popular protocol set, used by almost all BNs, MANs, and WANs.
4. Compare and contrast the three types of addresses used in a network.
The three types of addresses used in a network are the application layer, network layer and the Data link layer. When users work with application software, they typically use the application layer address. For example, in Chapter 2, we discussed application software that used Internet addresses (e.g., www.tsu.edu). This is an application layer address (or a server name). When a user types an Internet address into a Web browser, the request is passed to the network layer as part of an application layer packet formatted using the HTTP protocol.
The network layer software, in turn, uses a network layer address. The network layer protocol used on the Internet is IP, so this Web address (www.tsu.edu) is translated into an IP address that is 4 bytes long when using IPv4 (e.g., 129.79.127.4). This process is similar to using a phone book to go from someone’s name to his or her phone number.
The network layer then determines the best
9/29/2012
3. What are the parts of TCP/IP and what do they do? Who is the primary user of TCP/IP?
TCP/IP has two parts. TCP is the transport layer protocol that links the application layer to the network layer. It performs segmenting: breaking the data into smaller PDUs called segments, numbering them, ensuring each segment is reliably delivered, and putting them in the proper order at the destination. IP is the network layer protocol and performs addressing and routing. IP software is used at each of the intervening computers through which the message passes; it is IP that routes the message to the final destination. The TCP software needs to be active only at the sender and the receiver, because TCP is involved only when data comes from or goes to the application layer. TCP/IP is the transport/network layer protocol used on the Internet. It is the world’s most popular protocol set, used by almost all BNs, MANs, and WANs.
4. Compare and contrast the three types of addresses used in a network.
The three types of addresses used in a network are the application layer, network layer and the Data link layer. When users work with application software, they typically use the application layer address. For example, in Chapter 2, we discussed application software that used Internet addresses (e.g., www.tsu.edu). This is an application layer address (or a server name). When a user types an Internet address into a Web browser, the request is passed to the network layer as part of an application layer packet formatted using the HTTP protocol.
The network layer software, in turn, uses a network layer address. The network layer protocol used on the Internet is IP, so this Web address (www.tsu.edu) is translated into an IP address that is 4 bytes long when using IPv4 (e.g., 129.79.127.4). This process is similar to using a phone book to go from someone’s name to his or her phone number.
The network layer then determines the best