9Y
k¶¼¯¥»9&‹:)
– ISO 7 layer reference model
– u}”Š–9&¸®»Šuš{qsC¸®»t‹‘›š‹†
~u‡‰q±­¯½À£]š‹|ŽL˜v‹'ƒzv
k¶¼¯¥»‹TCP/IP
k¶¼¯¥»‹TCP/IP
(±­¯½À£`p/Po
TCP/IP9Y
– k¶¼¯¥»Šuš{q„)N{ISO 7 layer reference
model ‹26Šu‡……•Žq5¸®»-I
– FEŠq7¸®»Š]›š‹–uš{q4Ž5d—™X
lEAŽuš
(±­¯½À£`p/Po
1
2
9Y
k¶¼¯¥»\HU3
OSI 7 Layer Reference Model
– f
¶¼¯¥»]š‹|8¸®»r¸®»‡‰b
`€›š‹{vŠq a‹‰žŠyw
– ;V
– ¡¾¬µ¢À©
k¶¼¯¥»q„9&‹:)
k¶¼¯¥»q„9&‹:)
k¶¼¯¥»J
– €˜Žd!J‰|‰všrŒžj‰všz“w
(±­¯½À£`p/Po
(±­¯½À£`p/Po
3
=KU3ÁÄÂ
=KU3ÁÅÂ
ÄÈÅÃ!ÄÈÆÃ!
f
G`J
ÄÈÇÃ!
@I¥¾´ºÀ¬Áx‘IBM370QÂ{"}œ›q¥¾´ºÀ
¬ŽŸ£«©‚š*>{?•˜›…
– ˆMKG`rˆG`q„%J‚šf
G
`ÁeG`M$)‚šrDŽ§¹²¾G<}G
Z‚š‹{iY
– Harry Nyquist (1924)
• Maximum data rate = 2H log2 V (bits/s)
– O7 (terminal) ‹¥¾´ºÀ¬ (host computer) .T
– S1(ecŒ—wŽ:R‚šz{^n
f f
¦À³©Áx‘m[ŒÂ+W‹¥¾´ºÀ¬f

+WqDŽh0B}J
– e¿/Ám
¿m[Â
– ¥¾´ºÀ¬±­¯½À£
– H: low pass filter bandwidth
– V: discrete level of signal
¸®·2
– Claude Shannon (1948)
– Ÿ°¼¤f
cŽqgŠ® ¨¬»€›…(e
• ²¡ªušec’,#
• Maximum data rate = H log2 (1+S/N)
• 300bit/sec, 1200bit/sec, etc.
– ³­¯Œ—wŽ
‚šz
– _+W (differential Manchester coding etc.)
– S/N: signal-to-noise ratio
(±­¯½À£`p/Po
4
5
(±­¯½À£`p/Po
6
1
YewMéíê
YewMéíê
YewMéîê
YewMéîê
ìóðë;
>Ÿ»ìóñë;
’
ÓèφÊè×ͳ-$˜§Ÿ§° »—:±ÚãÝ
ÒÂÙ°Êè×Ͳ·ÀG
ìóñë;
JŸ»ìóñë;
>
ËÍÒÞfFq²U]D‘µ²N=
– ¥¶¦¶°ÉçØàèÏÕÑÔæèÆËÍÒÞ²d(
• ‰…†E}¯§­²ÓÂÌÏä5a"s²yŸ
• ÓèÏHr X.25
– X.25
• IBM HDLCŸ»c8e±U]
• õôöËÍÒÞ
• ÉçØàèÏÕÑÔæèƵ²lX
– ÛçÐZ—ËÍÒÞZ—oZ²ÅÍÏÜÃÎ
õôö‚` - Metcalfe’s Ethernet
• 6ÉÍԗŠcÉÍÔ²v+
• ÁÚãÈèËáç)®²RÉÍÔ+
– Ethernet, Token Ring
– “‡ÓèφE}²z`
– ßÓÞE}¯0±b°½E}²_
– ™+€VÄçâÃçËÍÒޚ
– U]µ²<œN=
• 1200bit/sec L
± 1Mbps ²E}ÀGiéN²Ethernetê
• ÛçÐ?²E}n±4©½<œ/
• #ŒU]¯§­Ck¥ª—† ®¡½
A'ÕÑÔæèƃ•/l”"
A'ÕÑÔæèƃ•/l”"
7
YewMéïê
YewMéðê
ìóñë;
JŸ»ìóñë;
>
Ž§«†ËÍÒފc
ìóñë;
>Ÿ»ìóòë;
’
U][²Š,
– Wxe°¯ÖÑÈèÌ
8
– ¬²+¡°\¾
• #ŒU]¯§­² ISO/OSI
• .}gjCP¯§­² TCP/IP
• TˆÚåÇâÝçǯ!¨uI
• Šc²—2~Q
– ‹9ÚåÔÉä²%c`
•
ÉçØàèÏÛçбº½U]
– IBM/SNA, Digital/DECnet, Xerox/XNS, ….
• Sync. Link / HDLC / X.25
• Coax / Ethernet / XNS
• ÓÌÏä5as / ARPAnet
A'ÕÑÔæèƃ•/l”"
A'ÕÑÔæèƃ•/l”"
9
OSI 7 Layer Reference Model
10
OSI 7 Layer Reference Model
‹9ÚåÔÉäÀu½®²&Oe°ßÓä
– ñ‹9%
n-SAP (Service Access Point)
• Physical / Data Link / Network / Transport / Session /
Presentation / Application
Layer n+1
– ISO/OSIU]¯§­€1
n-PDU (Protocol Data Unit)
• ‹9ÚåÔÉä²S@ÀKh±1t
• 7°¢¯¹*¢²±£¾»¾«
Layer n
ìóñë;
p¿¼Ÿ»ìóòë;
’±Ÿ£­U]
R |¿¾m1
Layer n
Peer entity
– ›¢¶®¹^ßÓä (reference model) ¯§­¶¯¸½¤¯®—
†ÚåÔÉ䲄ƒÀKh©½¤¯±3
Layer n-1
n-PDU = Header + SDU (Service Data Unit)
– ‹9%ÚåÔÉ䱞£½{²PÀB§­·¾´ºœ
A'ÕÑÔæèƃ•/l”"
11
A'ÕÑÔæèƃ•/l”"
12
2
OSI 7 Layer Reference Model
ES (End System)
Physical Layer
ES (End System)
Application
NFS
Presentation
XDR
Session
Transport
/©±¢˜¯
(Upper Layer Protocol)
– ¥´£k†§Ÿ¢
h9o
– Sun RPC
TCP
IS (Intermediate System)
Network
• mF°ª¯ (e.g. 0: < +0.5v, 1 > 3.7v)
• §Ÿ¢
h9o (e.g. A>G, “­´Qa„ƒ¶
IP
Data Link
IEEE802.3
Physical
Ethernet Coax
KN/
h) (communication media) …-|€r§Ÿ¢
h9o+Z
h)E…+Z
– h)E†L6Hv}z‚wSC
– ,l…‡/µ¡´ž®³•/¶†L6…(xy2n
• ¡´ž®³•/‚Ÿ¢+Z{Œ‹z‚w't
Physical connection
Physical connection
7$¤Ÿ¢²´•dq/Up!
7$¤Ÿ¢²´•dq/Up!
13
Data Link Layer (1)
Data Link Layer (2)
¡´ž®³•/ (Layer 2)
='y†CJw*#
h)…-|€+Z{Œ‹r¥´£k†¨°´¬
h9o†+Z
– Physical Layer†D\Ot€,M
– HDLCfI‚}‹¡šž¯.O!YOt~·-·i†
¡´ž<9o
– LAN4‚}‹IEEE802.x™®´œ
• Ethernet 802.3
• Token Ring 802.5
• FDDI 802.9
– ¨°´¬¹§Ÿ¢…&P+Z
• 8†s‹¡´ž†"ˆŠ
– ¸†¥´£ws‹%…‡crcw5`
– ISDN„ƒ†?Rmb:^‰DLL‚|€+Z
CJ†`V
• I.100™®´œ‡rQ 9or¡´ž¨°´¬†+Z„ƒwˆŒ
‹
– h)†¥´£†e>G
– ¨°´¬¨”´«Ÿ¢ (frame format)
– Ž•›9o (MAC sub-layer)
7$¤Ÿ¢²´•dq/Up!
Physical layer‚…+Z{Œ‹z‚w]R
– KNR
hg‚
h9o‡‚[u‹†w@i
7$¤Ÿ¢²´•dq/Up!
15
Network Layer (1)
Network Layer (2)
¤Ÿ¢²´•/ (Layer 3)
CJ†`V
16
– ES, IS†Ž£°›†Bj
¡´ž®³•…*}‹z‚„yr¤Ÿ¢²´•†¥´£
k†¡´ž<D\;
– ES µWT™› ¬: End System¶k†i+Z
– ¥´£…-}‹Ž£°›†
– —´¢‘’D\ISµk™› ¬: Intermediate System¶‚|
€,_
– ¦–Ÿ¢†+Z
7$¤Ÿ¢²´•dq/Up!
14
17
– ¦–Ÿ¢†10
– ¦–Ÿ¢†Xg3
– $i
7$¤Ÿ¢²´•dq/Up!
18
3
Transport Layer (1)
Transport Layer (2)
†‘—~™†$ (Layer 4)
‡ƒ†–™yhŒ•~Qh End-to-EndPs"G
†‘—~™†$h7H
– ‰zƒ†npWm^WP|™Š~h0
– End-to-EndchPhDE
РES hgiΥ~ZVq
– ‰zƒ†hO
– v‘™>
– Œ•~ž|™Š~h>76
– Œ•~gdabU@3dfqŒ•†{“
– ‡ƒ†–™ychPh†‘—~™†Œ•†{“Z?\rq
• PsIX ES iUh†‘—~™†Œ•†{“s?
+‡ƒ†–™yNT/FS
+‡ƒ†–™yNT/FS
19
$Œ•†{“
Session Layer
Session Layers$Œ•†{“ (Upper Layer
Protocol) dj
}—$
Ph,Bfh"G
– tŒ’z™}—9g"G\rq
– tŒ’z™}—YohK:g'[.4\rq
20
– Transaction
– Session
Phg#]bU>s"G
– Transaction Logging & Roll-back operation
– Session Termination
tŒ’z™}—YoL`UPh5*Bf"Gd3
Bf>
+‡ƒ†–™yNT/FS
21
+‡ƒ†–™yNT/FS
Presentation Layer
Application Layer
Œ”€—„™}—$
…™hJ=(&
tŒ’z™}—$š)?$› (Layer 7)
22
BftŒ’z™}—s6-^q`khŒ•†{“
– }~„Ž˜Œ‘ƒ†‹w™Žh%A<[U…™Z8][J=˜>M
\rq`khC
– • 2œhJ=
– ˆu†abJ=^qY
» 1, 2, 4, less than 1 byte (6 bits), ….
– ˆu†x™‚™ieX^qhY
» Little Endian / Big Endian
– ;,tŒ’z™}—_hlhcifW
– R ™“h1ci SMTP (simple mail transfer protocol)
Z"G\rbWq
– ]Y]fZoR ™“17Hs/a`tŒ’z™}—Z2
[!
• MTA: sendmail, qmail, postfix, etc….
• MUA: Eudora, Mozilla Thunderbird, MS/Outlook, etc….
– O^qhŠƒ†x™‚™ieX^qhY
» MSB first, LSB first
+‡ƒ†–™yNT/FS
23
+‡ƒ†–™yNT/FS
24
4
n,±»­¢¹Q+
n,±»­¢¹Q+
n,±»­¢¹Q+
n,±»­¢¹Q+
ÃÆÅÂ-
²½¨L]n,±»­¢¹
ÃÆÆÂ-
[~G)
OSI':
– IBM SNA, DECNET, Xerox XNS
– AppleTalk, Novell Netware, NetBIOS
– AH~k†€ˆÀISOAH±»¥¤:Á
OSIn,±»­¢¹
– @~bo
– J´¬¹xX.500‰~DŠˆ
– CLNP, TP4, IS-IS, X400, …
TCP/IP
TCP/IP
– AH~i{ÀIETFAH±»¥¤Á
– RIP, EGP/BGP, OSPF
– TELNET, SMTP, DNS, FTP, SNMP, NTP, ….
– V!DARPA~AH„‹7OxS?R8j
– V!~S?R
{Yˆ
– @~EgRWx*ald
• ARPAnet, MILnet
3$®ª­¼¿ eu/Tt
3$®ª­¼¿ eu/Tt
25
²½¨L]±»­¢¹`h
²½¨L]±»­¢¹`h
n,±»­¢¹Q+
n,±»­¢¹Q+
AH–™2C(
ÄÂÂÂ-
,¿Ÿ« ©µQ+
–
–
–
–
DECNETwvSI Protocol
AppleTalk w TCP/IP±¸¡¿£·½’
Netware, NetBios w TCP/IP±¸¡¿£·½’
Xerox XNS: `hx‡„‹I
– ¥£·½,
– ±º¦½«¿£·½,5^
“Demise of protocols”
IBM SNA‰~ND˜
,Xxs/
– &"FO£¤«³
– #.>£¤«³Œ+m}—\~j”Ž{
– MPLS
– J2EE, .NET, GRID….
• &cB£¤«³}—f6‘q„{
• ºž£¿£¤«³r (Legacy System)
3$®ª­¼¿ eu/Tt
26
3$®ª­¼¿ eu/Tt
27
›|“5^
›|“5^
n,±»­¢¹5^RK0
¬¿§¸½ 5^
%l (multiplexing) p (demultiplexing)
28
– ,‘xb;z™,±»­¢¹œ%l†™
– Ethernet_ƒš™LAN5^
– HDLC_ƒš™R¯¡ª­95^
• – ¬¿§¸½ ±»­¢¹Œz™ IEEE802.3 (Ethernet) ‘x,±»­
¢¹„‹IP, AppleTalkœ<˜4|‚~Œ™y„ˆ~Š‹x
EthernetŒxb;±»­¢¹œ<
|‚~Œ™
TCP/IP±»­¢¹Z (TCP/IP Protocol Suite)
– PŒ=•
›š‹{™¢½°¶¿§®ª­¼¿ ¾±»­¢¹
– K IP  TCP
• Œ‘x,±»­¢¹1…‹p
®ª­¼¿ UM5^
±¸¡¿£·½5^
3$®ª­¼¿ eu/Tt
29
3$®ª­¼¿ eu/Tt
30
5
Multiplexing
Demultiplexing
Application
Presentation
DNS
Session Manager
TCP
Network
PAP
Presentation
Session
Transport
Application
PAP
FTP
UDP
IP
FTP
DNS
Session Manager
Session
TP4/AppleTalk
Transport
AppleTalk
Network
TCP
UDP
TP4/AppleTalk
IP
AppleTalk
Data Link
IEEE802.3 Ethernet
Data Link
IEEE802.3 Ethernet
Physical
CAT/5 cable
Physical
CAT/5 cable
a^`knX7@/-?
31
:dj`ZiP4)$
a^`knX7@/-?
32
a^`knX7@/-?
34
Encapsulation
Wd\i (encapsulation)
– dj`ZiQAdj`ZiPcY^`UWd\iHT
– (n-1) PDU = (n-1) header + (n)PDU
Application
– Pdj`ZiPcY^`U_n]=MGK
Presentation
/HT
Session
Transport
Network
Data Link
Physical
a^`knX7@/-?
33
#m"#
Network Layer Gateway
eh^`
_eh^`
0
&6GRHB
9(C2
!2;3M%,GIbn[g
lV^d
– '+a^`knXP*1
C2
–
–
–
–
ES (End System)
– :P5UHTMA
P2U>EHTFMCLD
NB
– Wd\i&OSJKAef
h.&M_n].&C<GB
• 8_n]PBQ
ES (End System)
Application
Application
Presentation
Presentation
Session
Session
Transport
Network layer gateway
Network
IPv4
35
Network
Data Link
Data Link
Physical
Physical
Physical connection
Physical connection
a^`knX7@/-?
Transport
a^`knX7@/-?
36
6
Transport Layer Gateway
Application Layer Gateway
ES (End System)
ES (End System)
ES (End System)
Application
Application
Application
Presentation
Presentation
Presentation
Application layer gateway
Session
Transport layer gateway
Session
Session
4/6 mapping
Transport
Transport
TCP
TCP
IPv4
IPv6
IPv4
IPv6
Application
Presentation
Transport
Network
ES (End System)
SMTPXW400
Session
Transport
Network
Network
Data Link
Data Link
Data Link
Data Link
Physical
Physical
Physical
Physical
Physical connection
Physical connection
ƒ~“•vIV/=U
Physical connection
Physical connection
37
Network
ƒ~“•vIV/=U
38
ƒ~“•vIV/=U
40
kfl
Qˆ’y
– Ti+Q6F,
– e"_poz•†|i
•
•
•
•
J
12–†~r"
€•}”v–‡‘•‹r"
ƒ~“•v–…w~r"
Ž”|Š•–yƒv{”r"
TCP/IPi
TCP/IPi'E
– s”}‡u•|fCiR
– 4go€•}”vAm4goƒ~“•vAi8!>\
@h
• _k`kgeix•tus\@
ƒ~“•vIV/=U
39
TCP/IPeiŒ€
TCP/IPeiŒ€
TCP/IP Protocol Suites
InterneteqpdZoˆ’y?
LAN[nƒ~“•vke]
3
x•tus–
ƒ~“•vPr8!>b
o„•‚eYƒ~“•ve
…w~rLM
Ni{|‹e:
– Computers: UNIX workstationsYPCYSupercomputers
– PDA, .G, K, B$, *#SH, SD,…
;&6g9<O5f)/-
Network
Gateway
– IETF (Internet Engineering Task Force)
– http://www.ietf.org/
Network
Gateway
Qˆ’yfad(
– %iŒ€j5QŒ€
ƒ~“•v–
x•tusrb^f0]Y7!
€•}”ve!>_pc‰|?
ƒ~“•vIV/=U
41
ƒ~“•vIV/=U
Network
42
7
TCP/IP Protocol Suits
Network Interface Layer
ˆƒ†˜›{k7gXrIP…›‚|”’kHI7tDZ
– hkoqhq
OSI
TCP/IP
7
Application
Message / Stream
– Next hop address h…›‚•™{u‡—k‘ƒŒ™|
Transport Packet
Port
– …›‚•™{š—›’kBn?f
– ˆƒ†˜›{Š›‡xyuk$
– I7
IP Datagram
IP address
Frame
Datalink Address
• IP…›‚|”’
• 4kHIœ…›‚•™{
kIPu‡— (next hop address)
u‡—
Application
0=i7
Presentation
Session
Transport
Transport
Network
Internet
Data Link
Network Interface
Physical
Hardware
(ˆƒ†˜›{FV/@U
k…›‚•™{
k†mk…›‚HI
– }›†xywtbf;irˆƒ†˜›{m…›‚tHIcr3Clˆƒ†˜›{
(ˆƒ†˜›{FV/@U
43
Internet Layer: IP
IPv4u‡—
IPv4u‡—
IPv4 / IPv6
ˆƒ†˜›{Nh†N
:lŽˆƒ†5j;ir
163.221.74.127/24
203.178.142.0/27
– ‰›‡t)jGcr
– …›‚•™{kLYtcr
IP (Internet Protocol)k6%
44
– ~ˆ{€“™—›‹ (connectionless service)
• IP …›‚|”’]I
• I†h†l6j~ˆ{€“™EtbiYœO
• z”›]<8crhIP…›‚|”’l-fpsrœBest Effort 
– w™‚›ˆƒ†
k†QkJ3Ct.
• ;irˆƒ†˜›{hkJ
• }›†xywj\`rˆƒ†˜›{w™‚y›kM+
• –›„v™| (routing)
(ˆƒ†˜›{FV/@U
163
221
74
127
0xA3
0xDD
0x4A
0x7F
Network part
Prefix length
(ˆƒ†˜›{FV/@U
45
IPv6
IPv6k
IPv6k6%
128bit u‡—
#25 QWw™‚›ˆƒ†k*Pt/[rkji
u‡—>Q
^iu‡—>Q
u‡—~›k1&
Host part
46
– 2Kasdu‡—
– "SWu‡—>Qk1/8t9
Classli_ied
RACi (aggregatable) u‡—2K
Aggregatable Global Unicast Address allocation
,!'kTa
3
13
FP
TLA
ID
32
NLA ID
16
SLA ID
(ˆƒ†˜›{FV/@U
64 bits
Interface ID
47
(ˆƒ†˜›{FV/@U
48
8
IP¬š¦©†
Z[
IP¬š¦©†Z[
›¼©”•“‘¼—§˜¥³
Hop-by-hop, destination oriented
IP module
– ›¼©”•“Z[>'
routing
• Z[Á“»¤­•¼¡
– ›¼©”•“tŒs†/"8z€pŽw‚t4
forwarding
• KY-‘¸·¢°
Forwarding and routing
interfaces
(input)
– KY-‘¸·¢°t(z~KY/"
– KY/"…z~t~¬š¦©†Z[
interfaces
(output)
ª¦©º¼˜“»¤­•¼¡a2…‹Ž¸¼§’»™
output I/F = f(destaddr): f(x) t routing
/"ª¦©º¼˜Wk/Ij
/"ª¦©º¼˜Wk/Ij
49
Transport Layer
TCP
!9E„²¨¸
Internet Transmission Control Protocol
– ®¹£¡e† end-to-end †\<N
4
– ®¹£¡†X
•
<IP address, port>
– gT
Host
¯¼©
– ©¶»¡¯¼©)†X&
– ¿–˜§¦©
– ©¶»¡¯¼©®¹©œ¸=…'M
•
•
•
TCP‚UDP‡†,€
{DŠ0t
v_q
rˆ 5678/TCP, 5678/UDP
–
• ±¦£¼ †dx…f‡„p
– i.1P
process
•
•
•
•
Internet
½[IP, IP, ®¹©œ¸D, [¯¼
©, ¯¼©)
Network Interface
– ®¹©œ¸D
•
•
– :]x€p„p¡©·¼°
process
peer entity †X
;@R'
TCP=6, UDP=17
\½
c¾
• Connection Oriented
• Virtual Circuit
Transport
– IP)†<NB
50
i.†S
±¦£¼ †hD†S
FU (acknowledgement)
V6†[ (retransmission)
Hardware
/"ª¦©º¼˜Wk/Ij
/"ª¦©º¼˜Wk/Ij
51
Virtual Circuit
UDP
Byte stream semantics
Internet User Datagram Protocol
– %A«“©[Ž‚lJA«“©t€vŽ
– 5ÀmOun‚m*ntoŽl?yŒ„p
– b
52
½3LFGz„p¾
• Connectionless
• ¨¼¤™¶°\
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Application Layer
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<+H:^ Presentation Layer
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• Internet Address, IP host address
• klvux
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• %'YE
• EthernetXbCEthernet Address Z4
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TCP/IP protocol suit
IP (IPv4 & IPv6)
Gateway architecture & routing
TCP and other transport protocols
Application Layer protocols
Newly added layer: presentation layer
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59
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Data Link Layer = multiple sub-layers (1)
Data Link Layer = multiple sub-layers (2)
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ISO/OSI Local Area
Network Definitions (8802)
Network Layer
Logical Link
Control Sublayer
Network Layer
CCITT X.25
(HDLC/LAPB)
Data link Layer
signaling
8802/2 LLC
Data link Layer
Media Access
Control Sublayer
CCITT Datalink
Layer Definition
8802/3
CSMA/CD
8802/4
Token Bus
ATM
8802/5
Token Ring
data
Adaptation Layer
ATM
Physical Layer
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Data Link Layer = multiple sub-layers (3)
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Network Layer
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Data link Layer
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Physical Layer
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management, etc….
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– ¸ÌºÇÌ° (tunneling) ŸEp™Ÿ5¨§˜†¦„
TP
• IPsec / VPN (Virtual Private Network)
• IP Multicasting
• :º¶¸Ëͯ~(Mbone, 6bone), overlay network
TP
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IP
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IP
NIF
NIF
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• 3.5v‚x
TP
TP
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Tunneling NIF
NIF
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NIF
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IP
NIF
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