Directions - Panko

bluegooseexchangeΔίκτυα και Επικοινωνίες

26 Οκτ 2013 (πριν από 4 χρόνια και 2 μήνες)

145 εμφανίσεις

HOMEWORK

CHAPTER 1: WELCOME T
O THE CLOUD

Last Name: ___________________________________

Fi rst Name: ___________________________________

Due Date: ____________________________________

DIRECTIONS

Pl ace your cursor at the end of a questi on an
d

hi t Enter. Thi s wi l l pl ace you i n the Answer styl e.

Thi s has al ready
been done for Part a) of Questi on 1.

TEST YOUR UNDERSTAND
ING QUESTIONS

1.

a) Why do you thi nk wi rel ess

i s such a bi g concern today i n networki ng and securi ty? (In thi s book, “do
you thi n
k” questi ons requi re you to go beyond what i s i n the text. You may not be abl e to answer them
perfectl y, but try hard because they are good l earni ng opportuni ti es.) [1
-
4]



b) Di sti ngui sh between cl oud data storage and synchroni zati on on the one hand and c
l oud software
servi ce on the other. [2
-
4]


c) What do you thi nk are the advantages of each? [2
-
4]


d) What do you thi nk are thei r di sadvantages? [2
-
4]


e) Why do you thi nk the bri ng your own devi ce (BYOD) revol uti on has made networki ng more di ffi cul t?
Li st

several i ssues. [1
-
4]

2.

Go to YouTube and watch “A Day Made of Gl ass” by the Corni ng Corporati on. Li st new ways of di spl ayi ng
i nformati on shown i n the vi deo.

[No Page Numbers]

3.

a) What i nformati on coul d Cl ai re l earn about i ndi vidual access poi nts?

[5
-
6
]


b) Di sti ngui sh between SSIDs and BSSIDs.

[5]


c) What i s a rogue access poi nt?

[6]


d) Why do you thi nk rogue access poi nts are dangerous?

[6]


e) Why i s central i zed wi rel ess management hi ghl y desi rable compared to “management by wal ki ng
around” as Cl ai
re does today?

[6]

4.

a) Li st major wi rel ess

LAN securi ty i ssues. [7
-
9]


b) Why i s BYOD securi ty so di ffi cul t today? [7]

5.

Why does

thi s book combi ne networki ng and securi ty? [7
-
8]

6.

a) Gi ve the book’s defi ni ti on of network
. [8]


b) W
hat i s a networked
appl i cati on? [9]


c)

What are Web 2.0 appl i cati ons?

[9]


d) What are soc
i al medi a appl icati ons? [9]


e) What
i s a host? [10]


f) Is your l aptop PC or desktop PC a h
ost? [9
-
10]


g) Is a smartphone a host? [9
-
10]


h) Why i s the network core shown

as a cl oud?

[10]


i )

Why may the user need to know more about hi s or her access l ink than about the network cl oud?

[10
-
11]

7
.

a) Are network speeds usual ly measured i n bi ts
per second or bytes per second? [13]


b) How many bi ts per second (wi thout a metri c prefi x) i s

20 kbps?

Use commas. [13]


c) How many bi ts per second (wi thout a metri c prefi x
) i s 7 Mbps? Use commas. [13]


d) How many bi ts per second (wi thout a metri c p
refi x) i s 320 kbps? Use commas. [13]


e) Is the metri c prefi x for ki l o k or K?

[13]


f) Express 27
,560 bps wi th a metri c prefi x. [13]

8.

a) Why i s payi ng for a transmi ssion l ine by the mi nute not too bad for voi ce
conversati ons? [15]


b) For what two reasons i s payi ng for a transmi ssion l ine by the mi nute bad for data transmi ssions?

[15]

9.

a) In pack
et swi tchi ng
, what does the source host do? [16
-
17]


b) About how l ong i s a
packet? [16]


c) Why i s fragmentati on done? [17]


d) Where
i s reassembl y done? [16]


e) What are th
e two benefi ts of mul ti pl exi ng? [17]


f) When a packet swi tch recei ves a packet,
what
deci si on does i t make? [17]


g) Do packet swi tches know a packet’s enti re path through a
network? [18]


h) I
n Fi gure 1
-
14, i
f Packet Swi tch A recei ves a packet addressed to Desti nati on Host W, where wi l l i t send
the packet?

10.

a) In Fi gure 1
-
15, how
many physi cal l i nks are there between the source host and the desti nati on host
al ong the i ndi cated da
ta l i nk? [20]


b) How many data l i nks are there between the source host and the desti nat
i on host? [20]


c) If a packet passes through ei ght swi tches betwee
n the source and desti nati on hosts, how many physi cal
l i nks wi l l there be? (Careful!) [19
-
20]


d) How

many data l i nks wi l l there be? [19
-
20]

11.

a) On the

ARPANET, expl ai n the functi ons of IMPs. [20]


b) How i s thi s l i ke what packet swi tches do today? [20]


c) How i s i t more than packet swi tches do today? [20]

12.

a) What organi zati on

sets Internet standards today? [22]


b) What does the IETF cal l i ts standards?

[21]

13.

a) How d
i d Ray Toml i nson extend e
-
mai l? [22]


b) How di d he change e
-
mai l addresses?

[22]

14.

What probl em di d Bob Kahn face?

[23]

15.

a
) What devi ce connects di fferent networks i nto
an i nternet? [23]


b) What i s the ol d name for thi s devi ce?

[23]

16.

a) Di sti ngui sh between i nternet wi th a l owercase i and Internet wi th an uppercase
I. [2
5]


b) Why are many networki ng concepts dupl i cated i n swi tched networks and

i nternets? [25]


c) What are the two l evel s of addresses
? [25]


d) How l ong are IP addresses? [25
-
26]


e) How are IP
v4

addresses usual ly expressed for humans
? [25
-
26]


f) Di sti ngui
sh
between packets and frames. [26]


g) A host transmi ts a packet that travel s through 47 networks. How many packets wi l l be there al ong the
route?

[26]


h
) How many frames
wi l l be there al ong the route? [26]


i ) Are frames carri ed i nside packe
ts? [26]


j)

Di sti ngui sh between
swi tches and routers. [27]


k) Di sti ngui sh between physi cal l inks, data l inks, and
routes. [27]


l ) Di sti ngui sh between

what happens at the i nternet and transport l ayers. [27
-
28]


m) Do IPv4, IPv6, or both use dotted deci mal notati on f
or human readi ng? [25
-
26]


n) Why are appl i cati on l ayer standards needed? [28]


o) Li st the numbers and names of the fi ve l ayers. [29]

17.

a) What are the rol es

of the Internet Protocol? [30]


b) What are the rol es of the Transmi ssion Control Protocol? [30
]


c) What are the l i mi tati ons of the User Datagram Protocol? [30]


d) Why i s UDP used someti mes? [30]


e) What i s TCP/IP? [31]

18.

a) In what sense i s January 1, 1983, the bi rthday of th
e Internet? [31]


b) In what sense i s i t not?

[31]

19.

a) What was
the Acceptabl e Use Pol i cy i n pl a
ce on the Internet before 1995? [31]


b) Why di d commerci al acti vi ti es on the Inte
rnet become acceptabl e i n 1995? [31]


c) What do we cal l the carri ers that provi de Intern
et servi ce? [31]


d) Why do they need to be i nterconn
ected?

[31]


e) At what l ocati ons do ISPs i nterconnect?

[31]

20.

a) Why do se
rvers need stati c IP addresses? [33]


b) What protocol provi des a cl i ent
PC wi th i ts dynami c IP address? [33]


c) What other confi gurati on i nformati on does
thi s protocol provi de?
[33]


d) Why shoul d PCs get thei r confi gurati on i nformati on
d
ynami cally i nstead of manual l y?

[34]

21.

a) To send packets to a target host, what must
the source host know? [34]


b) If the source host knows the host name of the target host, how can i t get th
e target host’s IP address?

[34]

22.

Both DHCP servers and

DNS servers send a host an IP address. These are the IP addresses of what hosts?

23.

a) Li st the hardware el ements i n the smal l home netwo
rk descri bed i n thi s secti on. [35
-
37]


b) For wi red
connecti ons, wh
at transmi ssion medi um i s used? [36]


c) What i s i ts connector
standard? [36]


d) What i s the standard for wi rel ess PCs and pri nters to connect
to a wi rel ess access poi nt? [36]


e) What are the fi ve hardware functi ons i n a wi rel ess
access ro
uter? [37]


f) Why i s the DHCP functi on nece
ssary? [37]


g) Why i s NAT necessary? [37]


h) What three servi ces does thi s network provi de to the desktop PC and the wi rel ess tabl et
? [37
-
38]


i ) Whi ch devi ces need to be confi gured? (Li st them.) [38]

END
-
OF
-
CH
A
PTER QUESTIONS

THOUGHT QUESTIONS

1.

a) In Fi gure 1
-
15, when Host X transmi ts a packet al ong the data l i nk shown, how many physi cal l inks are
there al ong the
data l i nk shown?


b) How many data l i nks?

[20]

2.

a) In Fi gure 1
-
20, how many physi cal l i nks, data

l i nks, and routes are there al ong the way when H
ost A
sends a packet to Host B?


b) When Host E sends to Host C? (Assume that hops wi l l be mi ni mi zed across swi tches

and routers.)


c) When Host D sends to Ho
st E?

3.

In a certai n network, there are ni ne routers
between Host R and Host S.


a) How many data l i nks wi l l there be al ong the way when Host R transmi ts a packet to Host S?

(Hi nt: Draw
a pi cture.)


b) How m
any routes?


c) How many frames?

4.

Why does i t make sens
e to make onl y the transport l ayer rel i abl e? Thi s i s not a si mpl e questi on.

5.

a) What does i t mean that data transmi ssion
i s bursty?


b) Why i s bursti ness bad i f you pay for a transmi ssion l ine by the mi nute?

6.

What l ayer fragments appl i cati on messages
so that each fragment can fi t i nsi de an i ndi vidual packet?

CASE STUDY

1.

A fri end of yours wi shes to open a smal l business. She wi l l sel l mi crowave sl ow cookers. She wi shes to
operate out of her

house i n a ni ce resi denti al area. She i s thi nki ng of usi ng a

wi rel ess LAN to connect her
four PCs. What probl ems i s she l i kel y to run i nto? Expl ai n each as wel l as you can. Your expl anati on should
be di rected to her, not to your teacher. Thi s i s not a tri vi al probl em.