Chapter 5

Question 1

Protocols

Answer 1

rules and procedures for communication and behavior

Question 2

Protocol suite

Answer 2

when a set of protocols works cooperatively

Question 3

Transmission Control Protocol/Internet Protocol (TCP/IP)

Answer 3

most common protocol stack (composed of more than a dozen protocols operating at different levels of the communication process)

Question 4

Example of how layers work together:

Answer 4

1: You start the web browser and your homepage is http://www.cengage.com
2: The web browser formats a request for your home page by using the Application layer protocol HTTP (the unit of information the Application layer works with is simply called “data”)
3: The Application-layer protocol HTTP passes the request down to the Transport-layer protocol (TCP)
4: TCP adds a header (the unit of information the Transport layer works with is called a segment
5: TCP passes the segment to the internetwork layer protocol (IP)
6: IP places its header on the segment (unit of information is now called a packet)
7: The packet is passed down to the Network access layer, where the NIC operates
8: A frame header and trailer are added
9: The frame is delivered to the network medium as bits on its way to the www.cengage.com server
10: The web server processes it and returns a web page

Question 5

Application-Layer Protocols

Answer 5

provides network services to user applications that access network resources. With most Application layer protocols, both a client and a server version exist

The Application layer provides these functions:

1: Access by applications to network services
2: Client/server data access
3: Name resolution
4: Dynamic address assignment
5: Authentication/user login
6: Data formatting and translation

Question 6

HTTP

Answer 6

Originally used to transfer static web pages written in HTML. Now is also used for general file transfer and downloading/displaying multimedia files.

Uses TCP as its Transport-layer protocol. Default TCP port number is 80