Mng khng dyRouter/ nh tuyn v Wireless Card/ Th mng khng dy Router chnh l trung tm ca mng khng dy ca bn: N kt ni mng ca bn vo Internet thng qua mt modem cp/DSL, chia s kt ni Internet cho nhiu my tnh v cc thit b khc, v kim sot ai c th truy cp vo mng ca bn. Chnh v th m router c xem l thnh phn quan trng nht. Qua th nghim nhiu router bng rng, chng ti nhn thy hu ht router u c cc tnh nng c bn nh nhau - tt c nhng loi chng ti th nghim u c bn cng Ethernet ( ni cc thit b c dy), v c nhiu cch kim sot ai kt ni vo mng. Tt c router chng ti th nghim u c tng la NAT (Network Address Translation), mt s c tch hp tng la phng chng tn cng DoS v cho php thit lp thm qui tc ngn cm hoc cho php da theo loi dch v, m ha WEP- Wire Equivalent Privacy/ M ho tng ng dy dn v WPA- Wifi Protected Access/ Bo mt truy cp mng Wifi, lc a ch MAC (Media Access Control). Mi thit b mng u c mt a ch MAC duy nht, router c th quyt nh vic truy cp bng cch cho php ch nhng thit b c a ch MAC khai bo trong danh sch mi c kt ni vo mng. Mt s router c cc tnh nng rt cn cho cc bc ph huynh qun l con em trong vic truy cp Internet v qun l t xa. Nhng router ny u c n-ten tho lp c cho nn bn c th thay th bng cc n-ten nhy hn hoc n-ten nh hng (xem 'M rng tm ph sng' trang 90). Tc ca cc b sn phm cng khc nhau trong cch th nghim ca chng ti. Mt ln na, v t nng vn bo mt nn chng ti ch so snh tc ch m ha WPA-PSK v khng kch hot cc tnh nng c bit nh Super G hay 'Afterburner'. Tt c cc router u dng trnh duyt web qun l, mt s c thm trnh hng dn tng bc. Tuy nhin trnh hng dn ch gip bn thit lp cho thit b hot ng nhng khng gip bn thit lp cc tnh nng cao hn (nh lc a ch MAC, kim sot dnh cho bc ph huynh). Cho d chn cch thit lp no, ban u bn nn dng my tnh kt ni c dy thit lp, ri sau mi thit lp card mng khng dy thc hin. Lm th s n gin hn nhiu so vi vic thit lp cng lc cho c router v card mng khng dy hot ng. Thit lp cc ch tng tc khng phi lc no cng d dng, bi v c th c nhiu thit b khng dy khc (chng hn nh cc my tnh xch tay tch hp card mng khng dy ca ai khc) c kt ni vo mng ca bn, gy nhiu v lm gim tc ca router. Vi cc router ci tin, bn c th x l vn ny bng cch thit lp cho chng hot ng hn ch tc cao v pht l nhng thit b 802.11g no khng c tnh nng nng cao tc . Kch hot tnh nng lc a ch MAC cng gip gii quyt c vn ny. Ni chung, card mng PCI v PC Card ca cng mt nh sn xut dng chung phn mm (trnh iu khin thit b kim sot phn cng th khc nhau). Hu ht cc phn mm ny d dng v gip cho vic thit lp card mng tng i d dng hn. Printer Server/ My ch in n Mc d bn c th dng tnh nng in sn c trong h iu hnh Windows chia s mt my in giao tip USB qua mng khng dy, nhng my tnh lp my in bt buc phi ang chy th ngi khc mi in c. Nu c my ch in n Wi-Fi th bn khng cn n mt my tnh lp my in v bn c th t my in bt c v tr no min sao n vn cn nm trong vng ph sng ca mng Wi-Fi.

Thit lp cc my ch in ny chng c g kh khn lm: bn chy tin ch thit lp cu hnh, lp my in vo cng USB ca my ch in, ri ci t v thit lp tin ch trn cc my tnh mun s dng my in. Nu tnh c thi gian thit lp my ch in Wi-Fi v my in th mt khong 30 pht. Tt c u c ti liu hng dn ci t r rng. Mt im ni bt khc l c hai u h tr giao thc in qua Internet, IPP - Internet Printing Protocol. IPP cho php bn in mt bn bo co chng hn ra my in t vn phng trong khi bn li ang ngoi vn phng. Ni chung, cc my ch in tng thch vi my in phun v laser, nhng chng c th khng tng thch vi cc my in a chc nng. Hu ht cc my in a chc nng khi c kt ni vi my ch th ch c th in, ch khng qut v fax c. V cui cng, nu ang tm mt my in mi, bn hy th xem qua cc my in ca HP tch hp sn my ch in khng dy, v d nh loi Photosmart 8450 (find.pcworld.com/44230) v Photosmart 2710 all-in-one (find.pcworld.com/44232), ngha l khng cn phi mua thm my ch in. Bridge Wifi / Cu ni Wi-Fi Thm cu ni Wi-Fi l bn c th kt ni hu nh bt c thit b no c giao tip cng Ethernet, chng hn mt my in mng, vo mng khng dy. Bn dng cp ni thit b vo cng Ethernet ca cu ni, v cu ni s truyn d liu t thit b ny n cc thit b khng dy. Lc ny, bn thn thit b hot ng chng khc g vi khi lp vo mng c dy. Thit lp cu ni khng kh, ch hi mt cng khi g kha m ha. Bn nn mua cu ni v router ca cng nh sn xut, nht l khi mun tn dng cc ch nh Super G, Afterburner, v nh chn loi c h tr m ha WPA. Antenna/ Thit b khuych i th ng V khng th to c mi trng th nghim hon ton ging nhau so snh cc Antenna nn TestLab cha chnh thc th nghim cc Antenna. Chng ti ghi nhn li nhng kinh nghim ca nhm th nghim Test Center ca PC World M bn c tham kho. Nu th t router khng dy nhiu v tr khc nhau m vn cn mt vi 'im cht' (v tr khng c sng) trong nh, hy ngh n thit b m rng vng ph sng. Cng tn hiu quyt nh tc mng khng dy, tc mng gim rt nhiu khi cng tn hiu yu i. Cch d nht v t tn km nht tng tm ph sng cho mng l thay th Antenna ca router bng Antenna khc c kh nng thu/pht tn hiu tt hn. Tuy nhin, khng phi router no cng c n-ten tho lp c. (Kim tra trong bng so snh tnh nng). Trong bt c tnh hung no, ch nn dng Antenna nh hng khi bn mun ph sng mt khu vc no y, bi v cc phng khng nm trong hng ca Antenna s khng nhn c tn hiu, nu c th cng rt yu. Mt s Antenna cho php iu chnh cng tn hiu, ch nn tng cng tn hiu bao ph cc im cht, trnh m rng vng ph sng sang nh hng xm. Hu ht cc hng sn xut thit b khng dy u c Antenna tng cng kh nng ph sng. Bn nn lin h trc tip vi cc nh phn phi sn phm chnh thc hi thng tin v nh t vn chn la n-ten ph hp yu cu. Camera Wireless/ Camera khng dy

Bn c th lp mt camera wireless hu nh bt c ni no min ni c sn ngun in l c. Bn c th chn mt s loi Internet camera khng dy c th tm c th trng Vit Nam, nh PLANET ICA-100W. Cc camera ny u tch hp sn my ch web v th bn c th xem hnh nh t bt c my tnh no c trnh duyt web. Mun bit cc con bn i hc v

hoc kim tra vn phng trong khi i cng tc xa? Ch cn m trnh duyt Web. Mt s camera c kh nng khi pht hin chuyn ng th kch hot tnh nng ghi hnh v gi cnh bo qua email. Ngoi ra, mt s loi cn c micro thu m v m-t cho php bn iu khin t xa hng camera n nhng khu vc no cn quan st, nhng gi t hn. Cc loi ny u c ng dng thu/pht li hnh v qun l cng lc nhiu camera. Tuy nhin, trong s ny khng c loi no c th lp t ngoi tri v khng thu c hnh trong mi trng thiu sng. Thit b nghe nhc v xem phim Hin th trng Vit Nam bn kh tm c nhng thit b xem phim v nghe nhc h tr kt ni khng dy. C l cc sn phm loi ny s sm xut hin v nhu cu s dng mng khng dy ang tng dn. Bn c th kt ni vo dn m thanh hoc ch dng ring l nh thit b nghe nhc bnh thng v n c sn loa (c th tho ri loa), ngoi ra mn hnh LCD ca thit b ny ln v d c. Mt loi khc l HomePod ca MacSense (find.pcworld.com/44130), cng c sn loa nhng nh v m thanh cng yu hn. Tuy nhin, HomePod t ng tm cc tp tin nhc trn nhiu my tnh (Macintosh hoc PC) v c cng USB 1.1 bn lp cc thit b lu tr. trong khi LinkSys lm vic c ch vi mt my tnh v phi chy MusicMatch Jukebox. Ngoi MusicMatch, HomePod cng lm vic c vi iTunes, Winamp, v mt s trnh nghe nhc khc. C Linksys v HomePod u cho bn nghe li cc i trn Internet v Linksys c th bt c dch v nhc Rhapsody. Nhng chng c loi no h tr WPA nn chng khng kt ni c vo mng c kch hot m ha. Wireless Digital Media Player ca hng Actiontec (find.pcworld.com/44132) khuch i ng ra DVI xut tn hin ra tivi cao cp. Tuy nhin, ci t v s dng phn mm i km (phi ci t vo my tnh c lu tp tin phim v nhc) hi rc ri v thit b iu khin t xa khng c nt iu chnh m lng. Nu c my tnh Windows Media Center, bn cn c mt chn la khc: Media Center Extenders ca nhiu hng khc nhau s cho php bn truy cp tt c ni dung ca my tnh Media Center (nh chng trnh TV v nhc thu) trn tivi hoc dn m thanh. Microsoft cng s tung ra mt phn mm bin Xbox thnh mt Media Center Extender. Li th ca nhng thit b ny l bn khng cn phi mt thm thi gian hc cch s dng, chng s hot ng ging nh mt my tnh Media Center. Travel Kit/ Router du lch Router du lch l cc phin bn thu nh ca cc loi ln c th b ti, chng c km theo cc tin ch ci t chia s kt ni (nh mt cng Ethernet trong khch sn hay phng hi ngh) cho vi ngi. Chng cng cho php bn lu nhiu cu hnh thit lp, cho cc phng khch sn, cho nh, cho phng hp vn phng, gip cho vic kt ni d dng v nhanh chng hn v ch cn chuyn i cu hnh thit lp sn. 802.11g/ Chun G Mc d cc sn phm 802.11g hin ti c tc kh nhanh, nhng c nhiu tc v nh ti ng thi nhiu lung tn hiu hnh nh trn cng mt kt ni khng dy i hi bng thng phi ln hn so vi kh nng ca cc sn phm hin nay c th p ng. Chun 802.11n sp xut hin c th m rng bng thng v tng tm ph sng cho mng khng dy. Chun ny vn cn ang c bn lun, nhng c mt phin bn s cung cp bng thng trn 250Mbps, tc l cao hn bng thng ca cc sn phm chun 802.11g hin ti n hn 4 ln. 802.11n/ Chun N

Chun 802.11n tng bng thng bng cch nn d liu hiu qu hn v s dng n-ten cho php pht nhiu tn hiu cng mt lc (k thut ny c gi l MIMO - Multi In, Multi Out, tm dch l 'a nhp, a xut'). Chun ny c th phi n nm 2006 mi c cng b. Nu khng ch c n khi th chc bn s quan tm n tin ny: Mt s hng (nh Belkin; xem find.pcworld.com/44450) tung ra cc thit b Pre-N s dng chun do chnh h xut v tuyn b rng c th nng cp ln chun 802.11n khi chun ny c cng nhn.

Bo

mt

Nu con s thng k ng th c 5 ngi dng mng khng dy ti nh c n 4 ngi khng kch hot bt k ch bo mt no. Mc nh, cc nh sn xut tt ch bo mt cho vic thit lp ban u c d dng, khi s dng bn phi m li. Tuy nhin, bn cn phi cn thn khi kch hot tnh nng bo mt, di y l mt s sai lm thng gp phi. Sai lm 1. Khng thay i mt khu ca nh sn xut. Khi ln u tin ci t router khng dy, bn rt d qun thay i mt khu mc nh ca nh sn xut. Nu khng thay i, c th ngi khc s dng mt khu mc nh truy cp vo Router/ nh tuyn v thay i cc thit lp thoi mi truy cp vo mng. Kinh nghim: Lun thay mt khu mc nh. Sai lm 2. Khng kch hot tnh nng m ha. Nu khng kch hot tnh nng m ha, bn s qung b mt khu v e-mail ca mnh n bt c ai trong tm ph sng, ngi khc c th c tnh dng cc phm

Cc tnh ton c bn thit lp mng wireless LANBc 1: t k hoch (Kho st mng)

Bc ny da vo nhu cu ca khch hng chng ti s tm hiu v i n quyt nh t vn cho khch hng. Bc ny phi tr li cc cu hi di y. iu g khin cho bn quyt nh trin khai mng khng dy? Nu trin khai mng khng dy th bn s trin khai theo m hnh no di y:

M hnh Adhoc (Peer to Peer): m hnh ny thch hp vi mng nh s lng vi my tnh, khng cn im truy nhp Access Point, ch cn my tnh c card khng dy l c th chia s ti nguyn. M hnh Infrastructure: M hnh ny p dng cho h thng va v ln. Yu cu c im truy cp Access Point (hoc Gateway Access Point). M hnh ny va c th l khng dy hon ton, va c th l dng chung vi h thng mng c dy. Tn s s dng cho cc thit b mng khng dy nh Acccess Point, desktop, laptop, PDA l di tn no? Bao nhiu User c th s dng mt Access Point (hoc Gateway AP)

Tng s thit b dng mng khng dy nh PC, laptop, PDA, Printer Server...dng mng khng dy l bao nhiu. T tnh c s Access Point (Gateway AP)cn dng Bc 2: Chn loi thit b mng khng dy

Chn Card mng khng dy: USB, PCI, PCI CIA... Chn Access Point (hoc Gateway AP): tc theo chun no, c cc tnh nng g, chng hn nh DHCP, lc MAC, bn knh ph sng, tnh security..., (nu l Gateway AP th c tnh nng g, chng hn nh DHCP, NAT, VPN...). Bc 3: Trin khai mng

Ci t v kt ni cc Access Point (hoc Gateway Access Point ) vo mngCi t card mng khng dy sau kt ni vo h thng mng Bc 4: Trin khai an ninh mng

p dng cc bin php an ninh mng khng dy nh

Dng m ho WEP Key M ho Shared Key M ho WPA - PSK M ho WPA (Wireless Proteccted Access) dng kt hp Radius Server nhn thc v m ho ngi dng

Cc yu t nh hng n qu trnh truyn sng Di y l s qa trnh truyn sng t pha pht n pha thu, cc yu t nh hng n qu trnh truyn sng

Cng sut u ra thit b pht. Yu t ny ph thuc vo Access point (AP), chun AP, tc truyn dn ca AP. Cc thng s ny thng i km vi ti liu thuyt minh v sn phm.

Tn hao tn hiu trn cp pha pht. Tu tng loi cp di hay ngn, khi sn xut thng ghi sn suy hao ca loi cp ny. Khuch i tn hiu trn angten pha pht. Yu t ny ph thuc vo tng loi Angten v khi sn xut thng ghi sn khuch i Tn hao tn hiu trn ng truyn t pha pht ti pha thu. Thng s ny c cng thc tnh ton ( 32,4 + 20 log F ( Mhz) + 20 log R ( km ) ) Khuch i tn hiu trn Angten thu Tn hao tn hiu trn cp pha thu nhy ca thit b pha thu: nhy ca thit b pha thu do cng ngh sn xut sn phm, thng s ny cng nh th cng

tt.S qu trnh truyn sng t bn pht n bn thu

Mt s bi ton c th trong m hnh kt ni mng LAN to LAN ch bridge Bi ton 1

Dng Wap-4000 tc 54Mbps ca PLANET, angten Yagi 20dBi, tnh ton khong cch ti a khi kt ni 2 mng Lan gia 2 to nhWap-4000 hot ng di tn 2,4GHz (= 2400MHz) , vi tc 54Mbps th nhy thu l: 68dBi (thng s ny tu vo tc truyn), cng sut u ra l 13dBi Cng thc tnh suy hao khong cch = 32,4 + 20logF(MHz) + 20logR(km) = 32,4 + 20log2400 + 20logR = 100 + 20logR Tn hao trn cp pha pht l: -3,5dBi Khuch i trn angten thu l 20dBi (Angten Yagi 20dBi) Thng s EIRP l thng s tng cng tnh ton bi ton c t yu cu khng, thng thng EIRP > = 5 l tt. y ta ly bng 5 Tt c cc thng s ny c tnh ton nh bng di dy . Bng ny p dng cho tt c cc trng hp tnh ton lin quan n angten trong m hnh LAN to LAN (Bridge) Cng sut u ra pha pht Tn hao trn cp pha pht Khuch i tn hiu trn angten pht Suy hao tn hiu trn ng truyn ( suy hao khong cch ) Khuch i trn angten thu Tn hao trn cp pha thu nhy thit b thu EIRP (Effective Isotropic Radiated Power) Cng tt c cc thng s trong bng trn tnh c R EIRP = 5 = 13-7+40+68- ( 100+20logR ) => R = 2,81km . Nh vy khi dng Wap-4000 tc 54Mbps , angten 20dBi th khong cch truyn ti a c 2,81km. Ch : xem thm S qu trnh truyn sng t pha pht n pha thu hiu r hn v cc thng s trong bng tnh trn ng thi phi xem thm thng s k thut ca sn phm bit cc thng s v cng sut pht, nhy thu, tn hao tn hiu trn cp 13 -3,5 20 -(100 + 20logR) 20 -3,5 - (-68) 5

Bi ton 2 Yu cu v tc v khong cch. Gi s yu cu tc mng khng dy phi t c l 36 Mb/s, khong cch truyn l 10, thit b no ca PLANET p ng c yu cu ny? Gi s chn thit b l Wap 4000, angten nh hng Yagi c khuch i 20 dBi. Da vo bi ton 1 ta s tnh tt c cc thng s sau cng li ta c tng l EIRP, EIRP ny phi > = 5 nu khng tho mn ta s phi chn thit b khc. Cng thc tnh suy hao khong cch = 32,4 + 20logF(Mhz) + 20logR(km) = 32,4 + 20log2400 + 20log10 = 120dBi

Xem thng s ca Access Point Wap-4000 nu truyn tc 36Mbps th cng sut pht l 15dBi, nhy thu l: -76dBi

Cng sut u ra pha pht Tn hao trn cp pha pht Khuch i tn hiu trn angten pht Suy hao tn hiu trn ng truyn (suy hao khong cch) Khuch i trn angten thu Tn hao trn cp pha thu nhy thit b thu EIRP (Effective Isotropic Radiated Power)

15 -3,5 20 -(120) 20 -3,5 - (-76) ?

Cng tt c cc thng s trong bng ta c EIRP = 4 khng tho mn. Nh vy ta c th tng khuch i Angten hoc l thay i Access Point c nhy thu v cng sut pht cao hn. trng hp ny ta c th thay angten 20dBi.

Ti

u

v

bo

mt

mng

Wi-Fi

Ngy cng c nhiu mng Wi-Fi c cung cp min ph. y va l tin tt va l tin xu. Tt bi bn c nhiu la chn; xu bi kh nng hacker t nhp t xa vo my tnh cao hn. Di y l mt phng php ti u v gi cho mng Wi-Fi ca bn lun c an ton. 1. Ti u Wi-Fi cho VoIP, video, v game.

Nu tn hiu Skype hoc phin kt ni Second Life

c vn , hoc ting t trnh nghe nhc iTunes t nhin gim i... khi bn tr chi World of Warcraft, th n lc bn cn ti u mng Wi-Fi chng hot ng tt hn thay v phi mua mt router mi. Phn ln router c bn trong vi nm tr li y u c tnh nng QoS, tuy nhin bn vn cn phi nng cp phn mm c s (firmware) kch hot chng. Chng hn, chng trnh cu hnh cho router Linksys c th QoS di phn "Applications & Gaming" (hy chc rng tnh nng WMM Support c kch hot). 2. Kch hot cc ng dng QoS

Bt tnh nng Internet Access Priority dnh cho thoi v cc ng dng media. Trc tin, hy chn tng ng dng t danh sch x xung. 3. u tin gi d liu

Tip sau , chn cc mc u tin High, Medium, Normal, hoc Low, ri nhn nt "Add". C th bn s nh mc u tin "Low" cho nhng ng dng nh BitTorrent v cc dch v download khc, v trao cho dch v VoIP mc u tin cao nht. Hy ch rng tin ch Linksys cng cho php bn nh mc u tin cho cc thit b thoi ring khc, chng hn nh in thoi VOIP kt ni trc tip vi mng Internet. Khng phi tt c router u c th ti u cc ng dng hoc thit b c th, nhng t nht bn cng nn kch hot tnh nng QoS hoc WMM chng t ng ti u giao vn media (mc nh tnh nng ny khng c kch hot bi phn ln cc router). 4. Tt Wi-Fi khi khng s dng

Khi bn ra khi nh, tt hn ht l hy tt hon ton b iu hp Wi-Fi, ngn cho chng khng kt ni ti mt hotspot nguy him no , v cng l tit kin pin cho laptop. Mt s mu laptop mi c nt tt ny; nu khng c th bn tt tnh nng Wi-Fi trong Windows XP: nhn vo biu tng mng khng dy trn khay h thng ri chn "Disable". 5. Kch hot Wi-Fi trong Windows XP

Mun bt li kt ni Wi-Fi trong XP, bn m phn Network Connections trong Control Panel v nhn p vo kt ni khng dy. 6. Kch hot/v hiu ho Wi-Fi trong Windows Vista

kch hot hoc v hiu ho b iu hp Wi-Fi trong Vista, bn m Network and Sharing Center trong Control Panel, v chn "View status" di phn "Connections". Nu s dng phn mm iu hp ca nh cung cp, th rt c th bn s phi s dng phn mm iu iu khin kt ni Wi-Fi. 7. Truy tm k t nhp vo mng Wi-Fi

Mng khng dy ca bn c th b nhng k khc nhm ng. ng ngh rng vic m ho kt ni l an ton bi vic m ho Wi-Fi, nht l WEP, c th b ph. V ngay c b lc a ch MAC cng b gi mo. tng cng an ton cho kt ni Wi-Fi, bn nn ti phn mm min ph Network Magic. Chng trnh ny s gip hin th bn tt c cc my tnh, my ch media, my in v nhng thit b khc kt ni vo mng ca bn. Bt c mt thit b no khng phi ca bn u c th l k t nhp tim tng. 8. Nhn cnh bo khi thit b mi kt ni

Khng phi lc no ca s Network Magic cng bt ln bn thy c tt c cc thit b, nhng bn c th cu hnh chng a ra cnh bo khi mt thit b mi kt ni vo mng, c th iu tra ngay lp tc nguy c t nhp khi mi xy ra. lm iu ny, bn chn phn "Options" t menu "Tools", ri nhn vo th "Notifications" v nh du kim vo phn "A new device joins the network". 9. Truy tm "k mi n"

Cui cng, khi nhn vo th "Security", v nh du kim vo phn "Automatically track new devices as Intruders", bn c th theo di c hnh vi ca nhng "k mi n". Tnh nng ny rt hu ch trong trng hp khi bn khng ngi ti bn lm vic, ng lc k khc tha c "c

nc bo c". 10. Chia s hotspot

Router Wireless-G Travel ca Linksys c mt tnh nng quan trng m nhiu thit b khc khng c, l cho php bn chia s kt ni Wi-Fi hoc kt ni c dy. Bn c th s dng thit b ny chia s mt kt ni bng rng trong khch sn ( tr tin), hoc thng qua kt ni hotspot ca T-Mobile (mng di ng M). 11. S dng Wi-Fi chia s Wi-Fi

chia s kt ni Wi-Fi, n gin l ch cn bt router ln, kt ni thng qua mng Wi-Fi, v m tin ch cu hnh trong trnh duyt ra. Chn hotspot cn kt ni t danh sch cc mng c sn, ri nhn vo nt "Select". Mt ca s trnh duyt mi s m ra bn log vo hotspot, v thc hin thanh ton nu c. Nhng my tnh khc kt ni vo router Linksys Travel cng s kt ni vo hotspot ( tr tin) m khng phi chu thm phn ph ph no. 12. An ton kt ni hotspot

Cc hotspot cng cng thng l thin ng ca hacker. Nhng mng ny thiu kh nng m ho cn thit bi chng m cho tt c mi ngi. Tr khi bn s dng phn mm mng ring o (VPN), nu khng bt c ai cng c th thy c tt c cc giao vn Internet ca bn, bao gm

mt khu v thng ip e-mail. Nu bn khng kt ni qua VPN, th nn s dng mt phn mm VPN min ph khc c tn l Hotspot Shield t nh cung cp AnchorFree. Ch cn download phn mm v v ci t, ri sau kch hot ng dng. 13. Mng VPN c qung co

Trong khi ang kt ni, bn chn thuc tnh "Properties" t biu tng trn khay h thng xem a ch IP hin ti ca my tnh. Mc d phn mm Hotspot Shield min ph nhng n s t qung co trn trang web mi khi bn lt Web. Tuy nhin, nh i ly s an ton th y ch l ci gi rt nh. 14. V hiu ho mng Wi-Fi ngang hng

Mt trong nhng e do bo mt Wi-Fi thng dng nht l kt ni t mng Wi-Fi ngang hng (khng c Access Point), hay cn gi l mng Ad-Hoc. Hacker ch cn ngi mt ch, v d nh sn bay, ri sau pht qung b mt s nhn dng dch v (SSID) nh "T-Mobile" hoc "Free Wi-Fi" nhng laptop trong khu vc t ng kt ni vo, hoc t ngi dng nhn chn cc kt ni ny. Thc ra th rt t ngi dng s dng kiu kt ni ny, tuy nhin cho chc chn, bn nn v hiu ho tnh nng ny. Trong Windows XP, m phn Network Connections, nhn chut phi vo b iu hp khng dy, ri chn Properties. 15. Cu hnh Windows XP v hiu ho cc mng Ad-Hoc

Chn tip th Wireless Networks, v nhn vo nt "Advanced". 16. Tt mng Ad-Hoc

Cui cng, nhn vo nt "Access point (infrastructure) networks only". Hy chc rng bn b du tch trong phn "Automatically connect to non-preferred networks". By gi hy ng hp thoi vo v lu li nhng phn thay i. Trong Vista, bn khng phi v hiu ho mng ad-hoc, do bn phi chn th cng khi kt ni vo mng ny.

Tm hiu v Internet khng dy (Wireless Internet)Cng vic kinh doanh v cuc sng c nhn ca bn ngy cng ph thuc vo giao tip in t qua Internet. V vy Internet khng dy ra i. Chc chn bn tng thy ng dng ca Cellphone v PDA nhn v gi th in t. Mt bc tin pht trin logic mi quan h gia in thoi di ng v Internet. C l yu t quan trng nht trong s ra i ca Internet khng dy l Digital Cellphone trong nhng nm gn y. Vic m rng mng Digital Cellphone/ in thoi di ng cm tay v PCSPersonal Communication Services/ dch v thng tin c nhn to ra nn tng vng chc cho dch v Internet khng dy. Theo c lng th c hn 50 triu trang web cho php truy cp bng Cellphone. Nm 1997 Nokia, Motorola, Erisson v Phone.com hp tc cng nhau to ra WAP- Wireless Application Protocol/Giao thc truy nhp khng dy bi v h tin rng chun chung ton cu s

to ra s thnh cng ca Internet khng dy. Sau , hn 350 cng ty khc gia nhp din n WAP. to ra mt Website c kh nn thm nhp qua thit b khng dy tht s l mt th thch v vy ch c mt phn nh trong hn 1 t Website cung cp thnh phn Internet khng dy. WAP c thit k lm vic vi bt k dch v khng dy no tn ti nh: SMS- Short Message Service/ Dch v nhn tin ngn. CSD- High-speed Circuit-switched Data/ D liu chuyn mch tc cao. GPRS- General Packet Radio Service/ Dch v thng tin truyn gi tin qua mng radio . USSD- Unstructured Supplementary Services Data/D liu dch v b sung khng cu trc.

WAP-Wireless AccessPoint/ im truy nhp khng dy s dng WML bao Handheld Device Markup Language/ Ngn ng iu khin thit b pht trin

gm HDMLbi Phone.com. WML cng ch ra c ngun gc ca n t ngn ng nh du XML (Extensible Markup Language). Ngn ng nh du l cch thm cc thng tin ti thnh phn ca bn. Ngn ng nh du c bit n nhiu nht l ngn ng nh du siu vn bn HTML. Khng ging nh HTML, WML c xem nh l ngn ng Meta (Meta Language). V c bn iu ny c ngha rng WML cho php thit k ngn ng ca nh du ca chnh mnh. WAP cng cho php s dng giao thc Internet chun nh UDP, IP v XML. C ba l do chnh ti sao Internet khng dy cn giao thc ng dng khng dy WAP: Tc truyn. Kch c v kh nng c c. S iu hng (Navigation).

Hu ht cc Cellphone v cc PDA c chc nng truy nhp Web c tc truyn dn d liu 14,4 Kbps hoc thp hn so. Nu so snh vi Modem 56 Kbps thng thng, Cable Modem hay kt ni DSL ta s thy s khc bit ln v tc truyn. Hu ht cc trang Web ngy nay u c nhiu hnh nh nn s tn mt khong thi gian di Download vi tc 14,4 Kbps. Internet khng dy ch yu c thit k kiu Text-based gii quyt vn ny. Kch thc nh ca mn hnh LCD trn Cellphone hoc PDA li l mt th thch khc v hu ht cc trang Web c thit k phn gii 640x480 pixel ph hp khi th hin trn cc my Desktop hoc Laptop. Phn ln cc thit b khng dy s dng mn hnh n sc kch thc 150x150 pixel. Navigation l mt vn khc. Ngi dng ch cn nhn v click chut khi duyt qua Web nhng nu s dng thit b khng dy h thng s dng mt tay cun kho. Nhng iu xy ra khi thm nhp vo mt Website cho php truy nhp giao thc WAP: Bn bt thit b v m MiniBrowser. Thit b gi cc tn hiu v tuyn (Radio Signal) v tm kim dch v. Mt kt ni c to vi nh cung cp dch v.

Bn s la chn Website mun xem. Mt yu cu c gi ti Gateway Server s dng WAP. Gateway Server truy xut thng tin qua HTTP t Website. Gateway Server s m ho d liu HTTP thnh WML. Cc d liu m ho c gi ti thit b ca bn. Bn s thy c phin bn Internet khng dy ca trang Web bn la chn.

D liu c gi di dng HTTP bi WebServer ti WAP Gateway. H thng ny bao gm b m ho WPA- Wifi Protected Access/ Bo mt truy cp mng Wifi, b bin dch Script, Adaptor chuyn dng HTTP thnh WML. Sau Gateway s gi cc d liu c Convert ti cc WAP Client trn cc thit b khng dy. iu xy ra gia Gateway v cc Client ph thuc vo c im khc nhau ca ngn xp giao thc WAP (WAP Protocol Stack). WAE- Wireless Application Environment/ Mi trng ng dng mng khng dy:

Mi trng ng dng khng dy cung cp cc cng c pht trin thnh phn Internet khng dy. N bao gm WML v WML Script l ngn ng Script s dng chung vi WML c chc nng ging nh Javascript. Giao thc phin khng dy xc nh phin no gia thit b v mng s hng kt ni (Connectionoriented) hoc khng kt ni (Connectionless). Trong phin hng kt ni d liu thng qua c hai hng gia thit b v mng. Khi WSP s gi cc gi d liu ti lp giao thc Wireless Transaction Protocol Layer. Nu l phin khng kt ni, thng tin s c qung b v truyn t mng ti thit b, sau WSP nh hng cc gi ti lp giao thc Wireless Datagram Protocol Layer.WSP- Wireless Session Protocol/ Giao thc phin mng khng dy:

Giao thc thc hin khng dy hot ng nh l mt con thoi trn mng gi cho d liu logic v thng sut. WSP v WTP Layer p ng vi HTTP trong giao thc TCP/IP.WTP- Wireless Transaction Protocol/ Giao thc chuyn vn mng khng dy: WTLS - Wireless Transport Layer Security/ Bo mt mng khng dy tng vn chuyn :

cung cp nhiu c im bo mt nh TLS (Transport Layer Security) ca TCP/IP. N kim tra tnh trng d liu, cung cp cc phng php m ho, xc thc Client v Server. WDP- Wireless Datagram Protocol/ Giao thc chuyn mch gi qua mng khng dy: lm vic cng vi lp sng mang ca mng (Network Carrier Layer). WDP d dng tng thch WAP v tt c nhng thng tin c duy tr ti mc ny. Network Carrier- Cc sng mang ca mng: Cn c gi l bearer l bt k mt cng ngh no ang tn ti m nh cung cp khng dy s dng. Khi thng tin c nhn bi cc WAP Client, n s chuyn qua cc MiniBrower. y l ng dng nh xy dng trong cc thit b khng dy cung cp giao din gia ngi s dng v Internet khng dy. y l trang bt u ca trnh duyt Internet thng thng.

Ci t nhanh WSG-402 WIFI HotspotBc 1: Vo trnh duyt g a ch mc ch : http://192.168.0.1 Bc 2: Nhp username = admin Pass = password Bc 3: Cu hnh Lan : Advanced Setup -> LAN/WAN Nhp a ch LAN v d 192.168.16.222 vi subnet mark : 255.255.255.0 Cu hnh WAN : chn kt ni ADSL theo PPPoE (trc phi i modem sang ch Bridge) Bc 4: Chn cu hnh khng dy : Advanced Setup -> Wireless Chn Wireless vi SSID = NetcomID Chanel vi knh 1 (hoc 6, hay 11) Bc 5 : Chn kiu xc nhn : Advanced Setup -> Authentication Chn Build-in Authentication Bc 6 : Chn kiu tnh cc : Advanced Setup -> Billing Nu chn tr trc : Chn Pre-paid Chn time-to Finish vi kiu tnh cc s dng 1 ln (1 ln login) Chn Accumulation vi kiu tnh cc s dng nhiu ln (tch lu)

Nu chn tr sau : (ch s dng vi bn phm cng PS2) Chn Post-paid Chn s pht du di (Idle Time out = 5 ) Nu thay i ch tr trc sang tr sau, cc danh sch account s b xo ht v kt ni internet b xo. Bc 6: (Tip tc) Quy nh mc tnh cc Chn loi k hiu tin : Currency = VND Chn Tax Percent : Nu chn t gi % thu C 10 mc tnh cc theo thi lng s dng (Account usage time) v Charge (chi ph) Nhng s dng vi Account Printer ch s dng thay 3 mc u, nu s dng cc mc sau phi dng qua bn phm. V d : 30 pht = 8000VND phm +1 = phm A trn Account Printer 1h = 12000VND phm +2 = phm B trn Account Printer 2h = 20000VND phm +3 = phm C trn Account Printer

* S dng theo tc vi ngi tnh cc : Nu s dng phng thc tr trc (Pre-Paid): 1 - Ngi s dng yu cu 2 ting 2 - Ngi qun tr nhn phm C trn Account Printer (hoc nhn phm +3 ri nhn Enter) 3 - Ngi s dng nhn ho n c ghi user v password, anh ta vo trnh duyt, g trang web cn truy cp v d : www.vnn.vn Mn hnh tm thi chuyn sang mn hnh Login : G user v pass

Nu Pass ng, mn hnh t ng chuyn sang trang web anh ta cn s dng trong thi 2 ting. Nu s dng phng thc tr sau (Post-paid): 1 - Ngi s dng mun truy cp Internet 2 - Ngi qun tr nhn phm Enter trn bn phm 3 - Ngi s dng nhn ho n c ghi user v password, anh ta vo trnh duyt, g trang web cn truy cp v d : vnexpress.net Mn hnh tm thi chuyn sang mn hnh Login : G user v pass Nu Pass ng, mn hnh t ng chuyn sang trang web anh ta cn s dng. 4 - Ngi s dng khng mun truy cp cn thanh ton, a ho n tr sau cho ngi qun tr 5 - Ngi qun tr xem S/N ho n (v d :S/N :000123) g bn phm +000123 v nhn Enter 6 - Ngi qun tr a ho n tnh tin thi lng khch hng s dng (v thu tin theo % ca 1h) Cc chc nng cao cp Level 1 : Bc 7: Tnh cc cho dch v thng k Accounting : Chia lm 3 phn phn 1: Thit lp thi gian tn ti ca account theo gi ( Un-used account will be deleted after ) Thit lp thi gian tch lu trong khong hn nh ( Accumulation account will be deleted) phn 2 : Thit lp cu hnh tnh cc trn trnh duyt web m phng Account Printer ( Web-based Account Generator Panel ) Mc nh phm A mc 01, phm B mc 02, phm C mc 03 Chn u in ra : 1 .chn in qua Account Printer 2 .chn qua my in kt ni vi PC phn 3 : Chn phng thc gim gi nu s dng nhiu (Discount Plan) nu chn Enable mi c tc dng. C 10 mc la chn : mc 1 (level 1) khng gim gi, mc 2 ~ 10 hin th mc thay i, iu kin ( condictions ) lun > = Unit Price = s mc gi nhn vi 1h V d : mc 1 t Button Press =1, Unit Price = 1 mc 2 t Button Press =3, Unit Price = 1.5 mc 3 t Button Press =7, Unit Price = 1 Khi s dng c 1 h : cc ko c tnh gim gi = 2$ Khi s dng c 3 h : cc c tnh gim gi = 3 x 1.5$ = 4.5$ Khi s dng c 7 h : cc c tnh gim gi = 2 x 2$ + 4 x 1.5$ + 1 x 1$ = 11$ Bc 8: nh ngha KeyPad (cc phm nng tnh ho n cho tr trc) Bc 9: Customiztion (to ho n theo nh dng ring) Bc 10 : Filtering : Lc trang web, lc a ch IP Bc 11: Shared : Danh sch th mc ti nguyn chia s trong mng theo a ch IP v MAC my tnh Bc 12 : Portal Page :T ng vo trang web khi login thnh cng Bc 13 : Advertisement : ng ti qung b trang web trong danh sch 10 a ch Cc 30 pht = 1$ 1h = 2$ 2h = 3$ Print to :

Bc 14 : Walled Garden : cho php truy cp vo trang web (Nh cung cp c dch v c php) khng cn user name v pass. Bc 15 : DDNS : h tr tn min ng (phi enable chc nng NAT phn Advanced Setup -> Server) Bc 16 :LAN Device : h tr qun l cc thit b c th qun tr qua Web chng hn nh cc switch Web-smart. Bc 17 : SysLog : Ghi chp thng tin cu hnh trng thi ln 2 ng : Qua Syslog Server : theo a ch IP Qua th email : a ch mail- server, a ch mail ngi gi, a ch th ngi nhn, username v pass ca ngi nhn. Bc 18 : Chn lu v phc hi cu hnh : System Tool -> Configuration Back up : sao lu cu hnh theo a ch IP ca TFTP server v tn file ch Restore : phc hi cu hnh theo my tnh ang qun tr (Local PC file path) hoc a ch TFTP server Bc 19 : Firmware : Cu hnh phn mm iu khin WSG-402 C 2 mc : - Manual : bng tay : theo a ch IP ca TFTP - Schedule : Cu theo lch trnh thi gian t ng trn 1 TFTP cho trc

Ci t c bn cho AP ch repeaterHin trng h thng v mong mun Mt snh ln mt khch sn c chiu di 30mt, chiu rng 20mt cn ph sng cho cc thit b mng khng dy cc my tnh xch tay t do di chuyn trong snh truy cp mng LAN v Internet t h thng khch sn . Cn b tr khong 2 AP gia snh cc my tnh xch tay di chuyn m vn gi cc kt ni mng khng b ngt qung. Di a ch mng ca khch sn l 192.168.1.5 n 192.168.1.150 vi subnet mark 255.255.255.0 kt ni Internet qua modem c a ch 192.168.1.3 Ti y khng th i dy mng ti AP th hai, ch c mt AP th nht l nhn mng qua dy cp t switch. Cn thit phi ph sng ton b snh m khng phi thit k li gii php khc. Gii php S dng mt AP mode (phn ny trnh by phn trn) vi a ch 192.168.1.4 S dng AP th hai c a ch 192.168.1.3 hot ng ch Repeater. AP th hai ny s nm trong vng ph sng ca AP th nht, nhn SSID ca AP th nht v ph sng cho phn snh cn li. Khi cc my tnh dng thit b wireless s ch nhn thy 1 SSID trong danh mc AP list v kt ni mng thng qua n, AP th hai s trong sut vi m hnh WLAN trong snh. Cc AP thit lp ch Repeater cn mt AP chnh ch AP mode, cc AP xung quanh thit lp ch Repeater s khng cn kt ni mng c dy vi thit b, nhn sng t cc AP pht sng v c tc dng lp v ti to sng nhm tng khong cch ca chc nng AP pht sng.

Hng dn cu hnh Hng dn cu hnh AP ch Repeater cho Wap 4000 :Bc 1: Cu hnh AP ngun ch AP mode (xem li phn trc) Bc 2: Cu hnh AP Repeater : Truy cp cu hnh AP nh bi hng dn ci t c bn chn Advanced Setting , nh du chn Repeater Mode, in SSID ca AP ch AP Mode vo Remote AP SSID, hay nhp nt Site surveysau nhp Apply. Cc thng s cn li mc nh AP Repeater s pht sng khi nhn tn hiu t AP mode v cc my trong phm vi ph sng s lin lc vi cc my tnh trong phm vi AP chnh (AP-mode)

Ci t c bn cho Access Point ch BridgeHin trng h thng v mong mun

Hai to nh cng ty X cch nhau khong 105m c thit k cng lp mng vi m hnh LAN LAN nhng khng th ko dy c t bn ny sang bn kia (hay chi ph u t khi ko ng cp quang v thit b h tr kt ni cp quang qu ngun u t cng ty X). hot ng theo m hnh ny hai to nh b tr cc thit b 2 AP vi cc thit b ph tr annten v cp dy dn M hnh mng bao gm To nh A : c di a ch my tnh t 192.168.16.10 n 192.168.16.100 vi subnet mark 255.255.255.0 To nh B : c di a ch t 192.168.16.120 n 255.255.255.0 192.168.16.220 vi subnet mark

Cc to nh ni vi nhau sao cho khi ho mng cc my tnh bn to nh A c th lin lc bng dch v share folder, hay dng printer server nh trong mng LAN bnh thng. Gii php Kt ni khng dy gia hai to nh, 2 mng LAN s ho mng thng nht nh kt ni mng c dy. Kt ni khng dy 2 mng Lan cch xa nhau. Mi mng c mt AP lm vic ch Bridge v ta cn phi cu hnh 2 AP ny (2 AP cch xa nhau chnh v vy ta cn phi kt ni thm Angten c khuch i cao) . Khi 2 AP thit lp ch ny chng ch c nhim v kt ni 2 mng Lan vi nhau, cn mun kt ni vi Internet th chng ta vn phi thng qua Gateway nh mc Hng dn ci t c bn AP 2 Access Point hai to nh khc nhau ni mng vi nhau, chng phi c t cng a ch lp mng v d :192.168.16.x Hng dn cu hnh Hng dn cu hnh trn Wap 4000.Bc 1 : Hy lm theo mc Hng dn ci t c bn Access point (AP) i a ch c 2 AP v cng mt lp mng V d : AP th nht c a ch 192.168.16.1, Subnet Mask : 255.255.255.0 , AP th 2 c a ch 192.168.16.2, subnet Mask 255.255.255.0, cc thng s khc mc nh hoc khng cn phi cu hnh . Bc 2 : Vo trang web ca Access Point th nht ,vo tip Advanced Setting ,nh du vo Wireless Bridge ,sau in a ch MAC ca Access Point kia vo Remote Bridge MAC ( Xem a ch MAC ng sau AP hoc cng c th xem trong trang Web cu hnh thit b - mc Status )

Bc 3 :Lp li tng t bc 1+2 vi Access Point cn li Mun kim tra xem c 2 AP thit lp Bridge cha th ta ch vic Ping n 192.168.16.1 v 192.168.16.2 nu c 2 cng Reply -> chng kt ni c vi nhau .

Ci t c bn cho AP ch clientHin trng h thng v mong mun Hai phng ln ca mt cng ty cch nhau khong 10m, gia l cu thang rt bt tin cho vic i dy lin mng gia hai phng. Hn na mt phng l phng hp s dng cc thit b wireless cho cc my xch tay. Ta gi phng hp l phng H, phng cn li l C. H thng xy dng phi m bo lin mng m vn khng phi i dy lm mt m quan, gip cho c hai phng lin lc nh trong 1 mng LAN v qun tr mng d dng gim st ton b mng LAN.

Gii php Gii php chung cho h thng l thit lp mt AP ti phng hp dc kt ni vi mng LAN ca phng H. AP ny hot ng ch AP mode ph sng cho cc my tnh dng thit b Wireless. Phng C s dng mt thit b AP th hai kt ni vi mng LAN ca phng C, AP ny thit lp ch AP client nhn sng ca AP phng H. AP phng C s khng c tc dng ph sng m ch c tc dng nhn sng roaming ca AP phng H v ho 2 mng thnh mt mng thng nht. Cc AP c h tr AP client hot ng theo c ch th ng, tc l khi mt AP chnh pht sng ch AP mode, AP th hai ch client s ch nhn

Hng dn cu hnh Hng dn ci t ch AP Client cho Wap 4000Bc 1: Cu hnh AP ngun ch AP mode (xem li phn trc) Bc 2: Cu hnh AP Client : Truy cp cu hnh Wap 4000 ( nh hng dn cu hnh c bn ) : mn hnh Advanced Settting chn ch AP-Client, in cc thng s AP SSID trng vi tham s ny t trong AP pht sng ( ch AP mode), Chn Apply xc nhn thay i cu hnh.Cc thng s cn li mc nh.

Trong ch ny AP Client s khng pht sng, th kim tra bng my tnh c kt ni mng c dy ti AP-client ti cc my tnh c kt ni mng ti AP pht sng ( ch AP- mode)

T in thut ng Th t Thut ng 1 ADS 2 ATM 3 DDNS 4 DNS 5 6 NAT VPN

Ngha ting Vit Cc dch v th mc ng Ch truyn khng ng b H thng tn min ng H thng tn min Dch a ch mng Mng ring o

Ngha ting Anh Active Directory services asynchronous transfer mode Dynamic DNS Domain Name System Networking Address Translation Vitual Private Network