Synopsis TCP/IP networking fundamentals are the subjects that you need to master in the previous lecture. In this tutorial, you will review the following concepts by finding the answers for the 20 questions. Answers will be provided after the tutorial class.

protocols and networking stack;
the principles of IP protocol;
the features and differences between TCP and UDP protocols;
the concepts of ports, sockets and datagrams;
the common TCP/IP and UDP/IP application protocols; and
the functions of DNS, firewalls and proxy servers.

Questions

Protocol and Networking Stacks

Question 1: The OSI model has seven layers. List them from top to bottom.

Question 2: The IP networking stack has only five layers by combining three layers in the OSI networking stacks into the application layer. List the three layers in the OSI stack.

Question 3: Identify which layer of the IP networking stack the following protocols belong to: IP, TCP, UDP, FTP, HTTP, Ethernet frames.

IP: Internet Protocol

Question 4: What is the netmask number for a non-subnetted Class C network?

Question 5: Why there is no network that owns an IP address such as 127.x.x.x?

Question 6: Can you send data to 234.5.6.7? If so, what will happen?

TCP and UDP

Question 7: What is meant by connection-oriented and connectionless protocol?

Question 8: What features of TCP allow it to guarantee quality of service (QoS) in data delivery over the connectionless, non-guaranteed IP layer?

Question 9: What are the features of UDP that make many people happy to use it even though it is regarded as an ‘unreliable’ protocol (i.e. the delivery of data and its order is not guaranteed)?

Question 10: What do we mean by fragmentation of UDP datagram, and how can we avoid fragmentation?

The IP family of services

Question 11: What is the underlying protocol of the World Wide Web, and which network port does this protocol use?

Question 12: Name the protocol that is generally used to send email over the Internet.

Question 13: Name the protocol that is used to transfer accumulated email from the host to sporadically connected clients.

Question 14: Name the protocol that is used to transfer articles among servers in the USENET Internet news system.

Question 15: What is a ‘finger’?

Question 16: List some IP services that use UDP instead of TCP.

Question 17: What is the meaning of 8080 in this URL: http://www.xyz.com:8080/index.html?

Firewalls and proxy servers

Question 18: List the two main types of firewall techniques.

Question 19: What would you say about the relationship between a firewall and a proxy server?

Question 20: What are the three main purposes of using proxy servers?