1.3 According to the text, is it possible to develop Internet applications without understanding the
architecture of the Internet and the technologies? Support your answer. - Answers Answer: Yes, possible
to write code that communicates over a network, without understanding the hardware and software
technologies that are used to transfer data from one application to another. However, knowledge of the
underlying network system allows a programmer to write better code.
1.5 What is packet‐switching, and why is packet switching relevant to the Internet? - Answers Answer:
Packet switching divides data into small blocks, called packets, and includes an identification of the
intended recipient in each packet. Packet switching changed networking in a fundamental way, and
provided the basis for the modern Internet. Packet switching allows multiple senders to transmit data
over a shared network.
1.8 What is a communication protocol? Conceptually, what two aspects of communication does a
protocol specify? - Answers Answer: A communication protocol refer to a specification for network
communication. Major aspects of a protocol are syntax (format) and semantics (meaning) of the
protocol.
1.9 What is a protocol suite, and what is the advantage of a suite? - Answers Answer: protocols are
designed in complete, cooperative sets called suites or families, instead of creating each protocol in
isolation. Each protocol in a suite handles one aspect of communication; together, the protocols in a
suite cover all aspects of communication. The entire suite is designed to allow the protocols to work
together efficiently.
1.11 List the layers in the TCP/IP model, and give a brief explanation of each. - Answers Answer: The
TCP/IP consists of 5 layers. The layers and their short explanation is as follows: Layer 1: Physical:
Protocols in the Physical layer specify details about the underlying transmission medium and the
associated hardware. Layer 2: Network Interface Protocols in the Network Interface layer specify details
about communication between higher layers of protocols and the underlying network. Layer 3: Internet:
Protocols in the Internet layer form the fundamental basis for the Internet. Layer 3 protocols specify
communication between two computers across the Internet Layer 4: Transport: Protocols in the
Transport layer provide for communication from an application program on one computer to an
application program on another. Layer 5: Application: Protocols in the top layer of the TCP/IP stack
specify how a pair o applications interact when they communicate.
1.12 Explain how headers are added and removed as data passes through a layered model. - Answers
Answer: each layer on the sending computer prepends extra information onto the packet; the
corresponding protocol layer on the receiving computer removes and uses the extra information.
1.14 Give a brief explain of the layers in the ISO Open System Interconnection model. - Answers Answer:
ISO OSI model consists of 7 layers, namely:
, Layer 7: Application Layer 6: Presentation Layer 5: Session Layer 4: Transport Layer 3: Network Layer 2:
Data Link Layer 1: Physical Reader is expected to find out short explanation of each layer
3.1 What are the two basic communication paradigms used in the Internet? - Answers Answer: There
are various approaches, but according to textbook, we can specify them as Stream Paradigm and
Message Paradigm.
3.2 Give six characteristics of Internet stream communication. - Answers Answer: Characteristics of
Internet stream communication can be listed as follows: Connection ‐oriented 1 ‐to ‐1 communication
Sequence of individual bytes Arbitrary length transfer Used by most applications Built on TCP protocol
3.3 Give six characteristics of Internet message communication. - Answers Answer: Characteristics of
Internet message communication can be listed as follows: Connectionless Many ‐to ‐many
communication Sequence of individual messages Each message limited to 64 Kbytes Used for
multimedia applications Built on UDP protocol
3.5 If a sender wants to have copies of each data block being sent to three recipients, which paradigm
should the sender choose? - Answers Answer: The message paradigm is suitable for such transfer, since
it allows many‐to‐many communication
3.7 Give the general algorithm that a connection ‐oriented system uses. - Answers Answer: The
interaction between two connection‐oriented parties can be summarized as: Setting ‐up connection
between two parties Exchange information Terminate the connection
3.8 When two applications communicate over the Internet, which one is the server? - Answers Answer:
The application that waits for some other applications to contact is called server, and the application
that contact other one is called client.
3.10 What is the difference between a server and a server ‐class computer? - Answers Answer: The
server term refers to a program that waits passively for communication, and not to the computer on
which it executes. However, when a computer is dedicated to running one or more server programs, the
computer itself is sometimes called a server. Hardware vendors contribute to the confusion because
they classify computers that have fast CPUs, large memories, and powerful operating systems as server
machines.
3.11 Can data flow from a client to a server? Explain. - Answers Answer: Yes, data may flow in both
directions (client server and server client).
3.14 What two identifiers are used to specify a particular server? - Answers Answer: A particular server
is identified by the following identifiers: An identifier for the computer on which a server runs (IP
Address) An identifier for a particular service on the computer (Port Number)
3.15 List the steps a client uses to contact a server after a user specifies a domain name for the server. -
Answers Answer: The steps that a client uses to contact a server can be summarized as follows: