Starr_Tim-Sec02_HW2 - Tim Starr

gazecummingNetworking and Communications

Oct 26, 2013 (3 years and 10 months ago)

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Chapter 2
-
1

Homework

Chapter 2:

Layered Standards Architectures

Due Date:
9/12/05


Last name (family name):
Starr


First name (given name):
Tim


Test Your Understanding Questions

3.

a)

What is reliability?

Errors are corrected by resending lost or damages messages.


b
)

How does TCP implement reliability?



SYN, ACK responses

c)

In TCP, what is the receiver’s role in reliability?

Send acknowledgments in response to successfully received packets.


d)

In TCP, what is the sender’s role in reliability?

To open a connection
and wait for acknowledgement of successfully received
packets and store packets until there has been acknowledgement of successful
receival.


5.

a)

What do the internet and transport layers do collectively?

Specify what each router along the way does with pac
kets..


b)

Distinguish between what the internet and transport layer standards govern.

The internet layer governs the tranmission of packets across an internet and the
transport layer governs the aspect of end
-
to
-
end communication between two end
hosts.


c
)

What errors does the transport layer usually fix?

Transmission errors such as dropped packets or other errors at lower layers.
This is done so that the application layer can be assured clean data without
worrying about the specifics of it.

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2


d)

What do ap
plication layer standards govern?

Layer 5 application layer standards govern how two applications work with each
other.


11.

a)

Is Ethernet connectionless or connection
-
oriented? Explain.

Connectionless


b)

In a switched Ethernet network, are there timing
constraints on when a station may
transmit?

No, there are no timing constraints


12.

a)

The source and destination hosts are separated by four networks. How many packets
will there be?

One


b)

How many frames will there be?

Four


c)

How many routers will t
here be along the route? (Hint: Draw a picture showing the
hosts, networks, and routers.)

Three by the book’s convention but in the real world it’s different so I’m getting
confused.


d)

How many routes will there be?

One


e)

How many data links will there

be?

Three?
Four


f)

How many IP destination addresses will there be?

One


g)

How many destination data link layer addresses will there be?

Four?



h)

What will be the Layer 2 data link layer destination address in the frame in the first
network?

It’ll be
the MAC of the router


i)

What will be the destination IP address of the packet contained in that frame?

The IP of the target host on the other network.


15.

Two hosts are separated by ten routers.

a)

How many internet layer processes will be active on the tw
o hosts and the devices
between them?

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3

12 internet processes because internet layer is a hop
-
by
-
hop layer process so
there’s a process on each host and the ten routers.



b)

How many transport layer processes will be active?

Only two. This is because the tr
ansport layer is an end
-
to
-
end layer.

b)

Which layers are hop
-
by
-
hop layers?

Layers two and three


d)

Which layers are end
-
to
-
end layers?
(The physical layer is not considered to be either.)

Layers four and five

24.

a)

What is the standards agency for TCP/IP?

Internet Engineering Task Force (IETF)


b)

What are most of this agency’s documents called?

Request for Comments (RFCs)


c)

In which

At what

layers is TCP/IP dominant?

Layer Four (TCP) and layer three (IP)


d)

How dominant is TCP/IP today at these layers

compared to OSI’s dominance at the
physical and data link layers?

They are about equal because most people don’t use the OSI’s equivalence of
TCP/IP but rather TCP/IP usually uses OSI’s data link and physical layer’s
standards.


e)

Which of the following
is an architecture: TCP/IP, TCP, or IP?

TCP/IP is an architecture because it provides a broader plan of what standards
to use.


f)

Which of the following are standards: TCP/IP, TCP, or IP?


TCP and IP are standards.