wifi 2 infrastruktur wireless lan

7/25/2019 Wifi 2 Infrastruktur Wireless LAN

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Wireless LANWireless LANInfrastructure DevicesInfrastructure Devices

Dahlan AbdullahEmail : [email protected]

Web: http://www.dahlan.web.id


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Access PintAccess Pint


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Install AP dalam wired netwr!Install AP dalam wired netwr!


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" #de $nfi%urasi AP" #de $nfi%urasi AP

Root Mode

Repeater Mode

Bridge Mode


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&t #de&t #de


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'rid%e #de'rid%e #de


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&epeater #de&epeater #de


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Wireless 'rid%eWireless 'rid%e


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Pen%%unaan Wireless 'rid%ePen%%unaan Wireless 'rid%e


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( mde !muni!asi wireless( mde !muni!asi wireless

brid%ebrid%e

Root Mode Salah satu bridge harus diset sebagai root bridge Bisa berkomunikasi dengan non-root bridge lainnya Tidak bisa berkomunikasi dengan root bridge lainnya

Non-root Mode Komunikasi bisa ke root bridgeAccess Point Mode Punya kemampuan memperbolehkan client connect

Repeater Mode Berada diantara 2lebih bridge Memperpan!ang segmen "ireless bridge


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Peralatan )an% berhubun%anPeralatan )an% berhubun%an

den%an wireless brid%eden%an wireless brid%e

#i$ed or %etachable Antennas

Ad&anced #iltering 'apabilities

Remo&able (modular) Radio cards*ariable +utput Po"er

*aried Types o, ired 'onnecti&ity


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Wireless Wr!%rup 'rid%es


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Pen%%unaan Wireless

Wr!%rup 'rid%es


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Wireless LAN client devices

P'M'.A / compact ,lash cards

0thernet / serial con&erters

1SB AdaptersP'. / .SA Adapters


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P*#*IA + *nverterP*#*IA + *nverter


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Wireless AdaptersWireless Adapters


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Wireless LANs: *haracteristicsWireless LANs: *haracteristics

Types

.n,rastructure based

Adhoc

Ad&antages

#le$ible deployment

Minimal "iring di,,iculties

More robust against disasters (earthuake etc)

%isad&antages

3o" band"idth compared to "ired net"orks (4-45 Mbits) Proprietary solutions

Need to ,ollo" "ireless spectrum regulations


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Infrastructure vs. Adhc Netwr!sInfrastructure vs. Adhc Netwr!s

in,rastructure

net"ork

ad-hoc net"ork

APAP

AP

"ired net"ork

AP6 Access Point

Source6 Schiller


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,ransmissin: Infrared vs. &adi,ransmissin: Infrared vs. &adi .n,rared

uses .R diodes7 di,,use light7

multiple re,lections ("alls7,urniture etc8)

Ad&antages

simple7 cheap7 a&ailable in

many mobile de&ices

no licenses needed

simple shielding possible %isad&antages

inter,erence by sunlight7 heat

sources etc8

many things shield or absorb .R

light

lo" band"idth 0$ample

.r%A (.n,rared %ata Association)

inter,ace a&ailable e&ery"here

Radio

typically using the license ,ree

.SM band at 289 :;< Ad&antages

e$perience ,rom "ireless AN

and mobile phones can be used

co&erage o, larger areas

possible (radio can penetrate

"alls7 ,urniture etc8) %isad&antages

&ery limited license ,ree

,reuency bands

shielding more di,,icult7

inter,erence "ith other electrical

de&ices 0$ample

a&e3AN7 ;.P0R3AN7

Bluetooth

Source6 Schiller


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Difference 'etween Wired andDifference 'etween Wired and

WirelessWireless

., both A and ' sense the channel to be idle at the same time7

they send at the same time8 'ollision can be detected at senderin 0thernet8

;al,-duple$ radios in "ireless cannot detect collision at sender8

A ' *

A

'

*

Ethernet LAN Wireless LAN


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#bile IP -&* 001:

#tivatin Traditional routing

based on .P destination address net"ork pre,i$ determines physical subnet change o, physical subnet implies

change o, .P address (con,orm to ne" subnet)7 or special routing table entries to ,or"ard packets to ne" subnet

'hanging o, .P address %NS updates take to long time T'P connections break security problems

'hanging entries in routing tables

does not scale "ith the number o, mobile hosts and ,reuentchanges in the location

security problems Solution reuirements

retain same .P address7 use same layer 2 protocols authentication o, registration messages7 =


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#bile IP: 'asic Idea

&uter

2

&uter

"

&uter

3 #N

4me

a%ent

Source6 *aidya


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#bile IP: 'asic Idea

&uter

2

&uter

"

&uter

3 #N

4me a%ent

rei%n a%ent

mve

Pac!ets are tunneled

usin% IP in IP

Source6 *aidya


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#bile IP: ,erminl%)

Mobile Node (MN) node that mo&es across net"orks "ithout changing its .P address

;ome Agent (;A) host in the home net"ork o, the MN7 typically a router registers the location o, the MN7 tunnels .P packetsto the '+A

#oreign Agent (#A) host in the current ,oreign net"ork o, the MN7 typically a router ,or"ards tunneled packets to the MN7 typically the de,ault router ,or

MN 'are-o, Address ('+A)

address o, the current tunnel end-point,or the MN (at #A or MN)

actual location o, the MN ,rom an .P point o, &ie" 'orrespondent Node ('N)

host "ith "hich MN is >corresponding? (T'P connection)


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Data transfer t the mbile s)stem

.nternet

sender

A

4A

#N

hme netwr!

frei%n

netwr!

recei&er

2

"

48 Sender sends to the .P address o, MN7 ;A intercepts packet (pro$y ARP)

28 ;A tunnels packet to '+A7 here #A7

by encapsulation

@8 #A ,or"ards the packet to the MN

Source6 Schiller

*N


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Data transfer frm the mbile s)stem

.nternet

recei&er

A

4A

#N

hme netwr!

frei%n

netwr!

sender

2

48 Sender sends to the .P address

o, the recei&er as usual7

#A "orks as de,ault router

Source6 Schiller

*N

& t li -&* "((1


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&everse tunnelin% -&* "((1

Source6 Schiller

.nternet

recei&er

A

4A

#N

hme netwr!

frei%n

netwr!

sender

"

2

48 MN sends to #A

28 #A tunnels packets to ;Aby encapsulation

@8 ;A ,or"ards the packet to the

recei&er (standard case)

*N


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#bile IP: 5ther Issues

Re&erse Tunneling

,ire"alls permit only >topological correct> addresses a packet ,rom the MN encapsulated by the #A is no" topological correct

Agent Ad&ertisement ;A#A periodically send ad&ertisement messages into their physical subnets MN listens to these messages and detects7 i, it is in home,oreign net"ork MN reads a '+A ,rom the #A ad&ertisement messages

Registration MN signals '+A to the ;A &ia the #A ;A ackno"ledges &ia #A to MN limited li,etime7 need to be secured by authentication

+ptimi


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#ulti64p Wireless Netwr!s

May need to tra&erse multiple links to reach destination

Mobility causes route changes

Source6 *aidya


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#bile Ad 4c Netwr!s -#ANE,1

;ost mo&ement ,reuent Topology change ,reuent

No cellular in,rastructure8 Multi-hop "ireless links8

%ata must be routed &ia intermediate nodes8

A B A

B

Source6 *aidya


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&utin% in #ANE,

Mobile .P needs in,rastructure ;ome Agent#oreign Agent in the ,i$ed net"ork

%NS7 routing etc8 are not designed ,or mobility

MAN0T

no de,ault router a&ailable

>e&ery? node also needs to be a router

'an "e use traditional routing algorithms

%istance *ector

periodic e$change o, routing tables (destination7 distance7 ne$t

hop) selection o, the shortest path i, se&eral paths a&ailable

3ink State

periodic noti,ication about current state o, physical links (,looding)

router get a complete picture o, the net"ork


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,raditinal &utin%A routing protocolsets up a routing tablein routers

A node makes a local choice depending on global

topology Source6 Kesha&


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Distance6vectr + Lin!6state

&utin%

Both assume router kno"s

address o, each neighbor

cost o, reaching each neighbor

Both allo" a router to determine global routingin,ormation by talking to its neighbors

%istance &ector- router kno"s cost to each destination

3ink state- router kno"s entire net"ork topology and

computes shortest path

Di t 7 t & ti


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Distance 7ectr &utin%:

E8ample

2

Source6 Kesha&

Lin! 3tate & tin% E ample


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Lin! 3tate &utin%: E8ample

Source6 Kesha&


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#ANE, &utin% Prtcls

Reacti&e protocols

%etermine route i, and "hen needed

Source initiates route disco&ery

0$ample6 %SR (dynamic source routing)

Proacti&e protocols

0$tension o, traditional routing protocols Maintain routes bet"een e&ery host pair at all times

0$ample6 %S%* (destination seuenced distance &ector)

;ybrid protocols

Adapti&e 'ombination o, proacti&e and reacti&e 0$ample 6 CRP (


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D)namic 3urce &utin% -D3&1

9hnsn;


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&ute Discver) in D3&

'

A

3 E

4

D

*

>

I

$

?

&epresents a nde that has received &&E fr D frm 3

#

N

L

Source6 *aidya


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'

A

3 E

4

D

*

>

I

$

&epresents transmissin f &&E

?

'radcast transmissin

#

N

L

93=

9BC= &epresents list f identifiers appended t &&E


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'

A

3 E

4

D

*

>

I

$

ENde 4 receives pac!et &&E frm tw nei%hbrs:

ptential fr cllisin

?

#

N

L

93CE=

93C*=


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'

A

3 E

4

D

*

>

I

$

ENde * receives &&E frm > and 4C but des nt frward

it a%ainC because nde * has alread) frwarded &&Ence

?

#

N

L

93C*C>=

93CEC=


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'

A

3 E

4

D

*

>

I

$

?

#

ENdes and $ bth bradcast &&E t nde DE3ince ndes and $ are hidden frm each therC their

transmissins ma) cllide

N

L

93C*C>C$=

93CECC=


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'

A

3 E

4

D

*

>

I

$

?

ENde D des nt frward&&EC because nde D

is the intended tar%etf the rute discver)

#

N

L

93CECCC#=


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&ute &epl) in D3&

'

A

3 E

4

D

*

>

I

$

?

#

N

L

&&EP 93CECCCD=

&epresents &&EP cntrl messa%e


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Data Deliver) in D3&

'

A

3 E

4

D

*

>

I

$

?

#

N

L

DA,A 93CECCCD=

Pac!et header sie %rws with rute len%th


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D3& Issues +ptimi


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Destinatin63euenced Distance67ectr -D3D71

9Per!ins;(3i%cmm=

0ach node maintains a routing table "hich stores ne$t hop7 cost metric to"ards each destination a seuence number that is created by the destination itsel,

0ach node periodically ,or"ards routing table to neighbors

0ach node increments and appends its seuence number"hensending its local routing table 0ach route is tagged "ith a seuence number routes "ith greater

seuence numbers are pre,erred

0ach node ad&ertises a monotonically increasing e&en seuencenumber ,or itsel,

hen a node decides that a route is broken7 it increments theseuence number o, the route and ad&ertises it "ith in,inite metric

%estination ad&ertises ne" seuence number

D ti ti 3 d


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Destinatin63euenced

Distance67ectr -D3D71

hen I recei&es in,ormation ,rom J about a route to C

3et destination seuence number ,or C at I be S(I)7 S(J) is sent

,rom J

., S(I) S(J)7 then I ignores the routing in,ormation recei&ed

,rom J

., S(I) L S(J)7 and cost o, going through J is smaller than theroute kno"n to I7 then I sets J as the ne$t hop to C

., S(I) S(J)7 then I sets J as the ne$t hop to C7 and S(I) is

updated to eual S(J)

B ?

& ti / P ti , d


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&eactive v/s Practive ,rade6

ffs

Reacti&e protocols 3o"er o&erhead since routes are determined on demand Signi,icant delay in route determination 0mploy ,looding (global search) 'ontrol tra,,ic may be bursty

Proacti&e protocols Al"ays maintain routes 3ittle or no delay ,or route determination 'onsume band"idth to keep routes up-to-date Maintain routes "hich may ne&er be used

hich approach achie&es a better trade-o,, depends on the tra,,ic andmobility patterns

? & ti P t l -?&P1


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?ne &utin% Prtcl -?&P1

94aas;F=

CRP combines proacti&e and reacti&e approaches

All nodes "ithin hop distance at most d ,rom a node I are

said to be in the routing


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?&P: E8ample

Radius of routing zone = 2


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,E&I#A $A3I4

S030SA. =

wifi 2 infrastruktur wireless lan

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