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network 12

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1
l
eqcia.12
monacemTa gadacemis servisebi
satelefono kompaniebma SesTavazes qseluri momsaxurebebi yvela im kompania
s romelmac amis survili gamoTqves
. qveqseli e
k
uTvnis operators, romelic uzrunvelyofs SemkveTs, mepatrones da
terminals sakomunikacio momsaxureb
ebiT.
aseT sistemas sazogadi qseli ewodeba. is sazogado satelefono qselis msgavsia da xSirad mis nawilsac warmoadgens.
1.1. maRalsiCqariani qseluri teqnologia
(SMDS –
Swiched Multimegabit Data Service)
pirveli momsa
xureba romelsac Cven ganvixilavT aris SMDS (Swiched Multimegabit Data Service –
maRalsiCqariani qseluri teqnologia
). is SemuSavebuli iyo Sedgenili, mravalmxrivi lokaruri qselis, qvedanayofebis mqone ofisebisa da qarxnebisaTvis, romlebic erT kompanias ekuTv
nodnen. SMDS Seiqmna belkoris mier 1980 wels magram ganviTareba hpova mobvianebiT 1990 wels regionalur da mcire manZiliT daSurebul qselebSi.
imisaTvis rom davinaxoT situacia romelSic SMDS warmatebulad imuSavebs unda warmovidginoT kompania oTxi ofisiT,oTx sxvadasxva qalaqSi, amasTan TiToeuli kompania aRWurvilia lokaluri qseliT. kompanias unda gaaerTianos es qselebi ise rom, paketebma SeZlon gadaadgileba erTi lokaluri qselidan meoreSi. am sakiTxis gadawyveta ori gziT SeiZleba. pirveli gzaa iqiraon eqvsi maRa
li siCqaris mqone kabeli da SeaerTon lokaluri qselebi ise rom rogorc naxazzea naCvenebi. aseTi gadawyveta ra Tqma unda SesaZlebelia magram Zviria.
alternatiuli gzaa SMDS
-
is gamoyeneba, swored ise rogorc meore naxazzea naCvenebi. SMDS qseli warmoadgens lok
aluri qselis maRali siCqariT muSaobis safuZvels, romelic paketebis erTi
LAN
-
dan, meoreSi gadatanis saSualebas iZleva. SemkveTis ofisebis lokalur qselebsa da SMDS qsels Soris
, satelefono kompaniebSi
gaWimulia damakavSirebeli xazi, romelic naqiravebia satef
ono kompaniisagan. Cveulebriv es xazi MAN
-
s warmoadgens.
2
satelefono kompaniebis momsaxurebaTa umetesoba Seqmnilia mudmivi, uwyveti trafikisaTvis, xolo SMDS ki SemuSavebulia
pulsirebuli trafikisaTvis. maqiravebi xazis gamoyenebas aqvs uaryofiTi Tviseba, e
s aris yovelTviuri gadasaxadi; pirveladi instalaciis Semdeg momxmarebels uwevs xazebis safasuris gadaxda imis miuxedavad gamoiyena Tu ara isini. cvladi trafikisaTvis naqiravebi xazebi Zviri gadawyvetilebaa da aq mas naTlad uwevs konkurencias SMDS
-
is fasi.
n
-
raodenobis lokaluri qselebi , romlebic mTlianad dakavSirebulni arian naqiravebi xazebiT, saWiroeben daaxloebiT
n(n
-
1)/2 sigrZis kabels, maSin rodesac SMDS saWiroebs mxolod
n sigrZis kabels uaxloes SMDS marSrutizatoramde.
SMDS
-
is warmeteba aris
LAN
-
is g
adatana
LAN
trafikSi. is sakmaod swrafi unda iyos samuSaos Sesasruleblad. standartuli siCqare aris 45 Mbps, MAN
-
s SeuZlia am siqareze muSaoba magram am dros isini ar arian komutirebulebi anu oTxi lokaluri qseli MAN
-
is gamoyenebiT gaiyvaneba erTi satelefon
o kabeliT Semdegnairad LAN
1
-
dan LAN
2
-
mde LAN
3
-
mde da LAN
4
-
mde. yovelive e ski SesaZlebelia mxolod im SemTxvevaSi Tu isini erT qalaqSi mdebareoben. SMDS
-
is SemTxvevaSi TiToeuli lokaluri qseli uerTdeba satelefono kompaniis komutators, romelic agzavnis pakat
ebs qselSi ise rom maT miaRwion daniSnulebis adgils.
SMDS
-
is mier SeTavazebuli servisebidan ZiriTadi aris paketebis miRweva martivi SeerTebis SemTxvevaSi. paketebis formati naCvenebia qvemoT moyvanil naxazze. mas aqvs sami veliesenia: mimRebi (anu daniSnu
lebis adgili sadac paketi unda mivides), wyaro (vinc mas gzavnis) da cvladi sigrZis veli, romeliSic aris 9188 baiti momxmareblis informaciisaTvis. manqana romelic gamgzavn lokalur qselSi mdebareobs uSvebs pakets kabelSi da SMDS yvela Rones xmarobs
raTa man
miaRwios daniSnulebis adgils, magram garantias ver iZleva.
SMDS paketis formati:
mimRebis
misamarTi
wyaros
misamarTi
Mmomxmareblis informacia
3
wyarosa da mimRebis misamarTebi Sedgeba 4 bitiani kodisagan, romelsac mosdevs 15 aTobiTi Semdgari satelef
ono nomeri. TiTeuli cifri kodirebulia oTx bitiani veliT. satelefono nomrebi Seicaven qveynis kods, regionis kods da damamzadeblis nomers. amgvarad, momsaxureba SeiZleba internacionaluric ki gaxdes. rodesac paketi miaRwevs SMDS qsels pirvel rigSi marSruti
zatori Secdomis Tavidan asacileblad Seamowmebs emTxveva Tu ara misamarTi Semomaval xazs. Tu misamarTi SecdomiT aris, pakets ubralod gadaagdeben, xolo Tu sworia igi igzavneba mimRebTan. SMDS
-
is sasargeblo Tviseba aris mauwyebloba. momxmarebelma SeiZleba gansazRvros SMDS satelefono nomrebis CamonaTvali da specialuri nomriT ganisazRvreba ukve mTliani es sia. nebismieri paketi, romelic am nomrisTvis aris gankuTvnili siis yvela wevrs miuva. ,,
National Associacion of Securities Dealers” iyenebs
MCI BMDS momsax
urebas 5000 wevrisaTvis axali fasis Sesatyobineblad.
damatebiTi Tviseba aris miRebuli da gagzavnili misamarTebis Semowmeba. gagzavnis Semowmebis dros momxmarebels SeuZlia misces satelefono nomrebis sia da gansazRvros, rom sxva misamarTze aranairi ar gaigza
vnos. Semomavali miRebuli misamarTis Semowmebis dros paketebi mxolod winaswar gansazRvruli satelefono nomrebidan miiReba. rodesac orive Tviseba aqtiuria momxmarebels SeuZlia efeqturad aagos kerZo qseli gare samyarosTan SMDS kavSiris gareSe. kompaniebisaTvi
s, romlebic kompedencialur informacias floben es Tviseba Zalian xelsayrelia.
P
Payload SeiZleba Seicavdes bitebis nebismier mimdevrobas, rogorsac momxmarebeli isurvebs 9188 baitamde. SMDS amas ar uyurebs. is SeiZleba Seicavdes EHernrt pakets da a.S. rasac ar unda Seicavdes es veli, igi ucvlelad gadaecema wyarodan mimRebs.
SMDS marTavs pulsirebul trafiks Semdegnairad: marSrutizatori, romelic yovel xazs uerTdeba Seicavs mTvlels, romelic izrdeba mudmivi sididiT. mag: 10 msec.
rodesac paketi miaRwevs marSrutiz
ators Semowmeba xdeba , mTvlelis sigrZe xom mar aRemateba paketis sigrZes baitebSi. Tue es asea, paketi dayovnebis gareSe gaigzavneba da mTvleli mcirdeba paketis sigrZemde. Tu paketis sigrZe metia mTvlelze, maSin mas gadaagdeben.
yovel 10 msec
gansxvaveb
iT momxmarebels SeuZlia saSualod 100000 bytes/sec, magram pulsacia SeiZleba gacilebiT maRali iyos. magaliTad, Tu xazze 10 msec ganmavlobaSi Tavisufali iyo, mTvleli 1000
-
is toil iqneba da momxmarebels saSualeba eqneba gadasces 4
1
kbijte pulsacia sruli 45 Mbps
siCqariT. is gadacemuli ioqneba daaxloebiT 18
msec
-
Si. 100000 bytes/sec siCqaris naqiravebi xazit igive kiloabiti 10 msec
-
Si gadaicema
1.2. X25 qselebi
Zveli sazogado qselebi gansakuTrebiT SeerTebuli Statebis gareT misdeven X25 standarts. is SemuSa
vda 1970 wels CCITT
-
is mier, iisaTvis, rom aReWurvaT interfeisi sazogado paketuri qselebsa da momxmareblebs Soris.
fizikuri donis protokoli, romelsac X25 ewodeba gansazRvravs fizikur, eleqtronul da procedurul interfeiss mflobelsa da qsels Soris. sinamdvil
eSi Zalian cota sazogado qseli uWers mxars am standarts, imis gamo, rom is iTxovs ufro metad satelefono xazis cifrul signalebs, vidre analogurs.
monacemTa kavSiris donis standarts aqvs ramodenima variacia. TiToeuli maTgani SemuSavebulia satelefono xazze monacemebis gadacemis SecdomebTan samuSaod momxmarebelsa da sazogado qsels Soris.
qseluri donis protokoli muSaobs misamarTebTan, nakadis marTvasTan, wyvetebTan da a.S. ZiriTadad saSualebas aZlevs momxmarebels Seqmnas virtualuri wreebi da gagzavnos 128 bai
tis moculobis paketebi. es paketi aRwevs daniSnulebis adgils saimedod (in order) rigiT. X25 qselebis umetesoba muSaobs 64
kbps
siCqareze, rac gamousadegars xdis maT bevri miznisaTvis. miuxedavad amisa, isini kvlavac farTod gavrcelebulni arian.
X25 aris ka
vSirze orientirebuli da mxars uWers orive komutirebul virtualur wredsac da mudmivsac. komutirebuli virtualuri wredi iqmneba, rodesac erTi kompiuteri ugzavnis pakets qsels da iTxovs zars Soreul kompiutertan dasakavSireblad. erTxel Seqmnili paketebi SesaZloa
gagzavnon mTeli SeerTebis gaswvriv, isini yovelTvis mowesrugebulad, mimdevrobiT midian. X25 uzrunvelyofs nakadis marTvas, radgan gamgzavns ar SeuZlia Seavsos dakavebuli mimRebi.
permanentuli virtualuri wredi gamoiyeneba iseve, rogorc komutirebuli, magram
Tan erTvis SeTanxmeba SemkveTsa da mflobels Soris. is yovelTvis arsebobs da aranairi zari ar aris saWiro mis gamosayeneblad.
5
imis gamo, rom qveyana jer kidev savsea iseTi terminalebiT, romlebic ver aRiqvaven X25
-
s, standartebis sxva erTobliob iqna SemuSa
vebuli. is aRwers Tu rogor urTierTobs Cveulebrivi terminali X.25 tipis sazogado qselTan. momxmarebeli an qselis operatori ayenebs “Sav yuTs”romelsac terminalebi SeiZleba SeuerTdnen. Sav yuTs ewodeba PAD (Packet Assembler Disassembler)
da misi funqciebi aRw
erilia dokumentSi, romelsac X3 ewodeba. standartuli protokoli SemuSavebulia terminalsa da
PAD
-
s Soris romelsac X.28 ewodeba. arseboba meore protokolic
PAD
-
sa da qsels Soris dam as X.29
-
s owideben. am samives erTad ki X sameulad moixsenieben.
1.3. Frame Re
lay
Frame Relay
aris servisi xalxisaTvis romelTac surT absolutirad kavSirze orientirebuli formiT gadaitanon bitebi
A wertilidan
B
-
Si, amasTan es unda ganxorcieldes normauri siCqariT da dabali fasiT (smiti, 1993). am qselis arseboba SesabamisobaSia gasul
i ori dekadis teqnologiur cvlilebebTan. oci wlis win komunikaciisaTvis iyenebdnen satelefono xazebs romlebic iyo neli, analoguri da arasaimedo Sesabamisad kompiuterebic iyo neli da Zviri. amis gamo saWiro gaxda kompleqsuri protokolebi Secdomebis SesaniRbad
, momxmareblis kompiuterebi ki Zalze Zviri iyo am samuSaos Sesasruleblad.
situacia radikalurad Seicvala. satelefono xazebi dReisaTvis aris swrafi, cifruli da saimedo, Sesabamisad kompiuterebic gaxda swrafi da SedarebiT dabalfasiani. yovelive es ki sTavaz
obs momxmarebels martiv protokolebs sadac samuSaos didi nawili Sesrulebulia momxmareblis kompiuteris da ara qselis mier.
Frame Relay
SeiZlba ganixilos rogorc saukeTeso virtualuri xazi. SemkveTi yofs virtualur wreds or wertils Soris ris Sedegac SeuZlia pak
etebis (freimebis) gagzavna. aseve SesaZlebelia gaiyos mudmivi virtualuri wredi mocemul, konkretul mxaresa da Sedgenil mxares Soris, am SemTxvevaSi TiToeuli freimi atarebs 10
-
bitian nomers romelic gansazRvravs Tu romeli virtualuri wredi unda iqnes gamoyene
buli.
gansxvaveba realurad da virtualurad dayofil xazebs Soris imaSi mdgomareobs rom realurad dayofiliT momxmarebels SeuZlia monacemebi mTeli dRis ganmavlobaSi maqsimaluri siCqariT gadsces,. xolo virtualuris SemTxvevaSi monacemTa impulsebi SesaZloa sruli 6
siCqariT gadices, magram am SemTxvevaSi xangrZliv gamoyenebas ganmsazRvreli done unda uswrebdes.
Frame Relay
uzrunvelyofs minimalur serviss, pirvel rigSi es aris freimis Tavisa da bolos gansazRvra, da gadacemuli signalebis Secdomebis Semowmeba. Tu daziane
buli freimi miiReba Frame Relay mas ubralod gadaagdebs. xolo freimis dakargvis aRmoCena da Sesabamisi zomebis miReba momxmareblis movaleobaa. X.25
-
sagan gasxvavebiT Frame Relay ar uzrunvelyofs nakadis kontrols. saTaurSi mas aqvs biti, romelic atyobinebs pr
oblemebis arsebobas. am bitis gamoyenebac momxmareblis movaleobaa.
ATM teqnologia
teqnologias romelic safuZvlad daedo B
-
ISDN da mis muSaobas uZrunvelyofs
ATM (Asynchronous Transfer Mode) teqnologia
ewodeba. is aris sinqronuli iseve rogorc grZeli satelef
ono xazebis umetesoba. aRsaniSnavia rom zemoT naxseneb ATM
-
s
araferi aqvs saerTo Automated Teller Machine
-
Tan Tumca ATM manqanas SeuZlia gamoiyenos ATM qseli bankTan urTi
erTobisaTvis.
ATM
-
Si ganxorciele
buli ZiriTadi idea aris mTeli i
n
f
ormaciis patara fiq
sirebuli zomis paketebad dayofa, romlebsac ujredebi ewodebaT. ujredis sigZe aris 53 baiti, aqedan 5 baiti aris saTaurisaTvis, xolo danarCeni 48 momxmareblisaTvis
. ATM Tavis TavSi moicavs rogorc teqnologias aseve serviss, zogjer rogorc serviss mas cell rel
ay
-
is uwodeben
frame relay
-
is msgavsad
ujredebis komutaciis teqnologia giganturi winsvlaa 100 wlian tradiciebSi. arsebobs ujredebis komutaciis upiratesobis ramodenime mizezi: pirveli –
ujredebis komutacia moqnilia da SeuZlia marTos rogorc mudmivi pulsacii
s (video, audio) aseve cvladi pulsaciis trafikebi (monacemebi), meore -
maRali siCqaris SemTxvevaSi cifruli ujredebis komutacia ufro, martivia vidre tradiciuli multipleqsuri teqnologia, mesame -
satelevizio monacemebis gavrcelebisaTvis ma
uwyebloba saukeTe
so saSualebaa. ujredebis komutacias es SeuZlia ganaxorcielos.
7
ATM qselebi arian kavSirze orientirebulebi. ujredis Seqmna pirvel rigSi iTxovs Setyobinebis gagzavnas kavSiris dasamyareblad. amis Semdeg momdevno ujredebi mizdeven igive gzas mimRebamde. ujred
is miRebis dadasturebisagan gansxvavebiT maTi mimdevroba garantirebulia. Tu magaliTad ujredi 1 da ujredi 2 aseTi mimdevrobiT gaigzavna, maTi miRebac igive mimdevrobiT moxdeba da ara piriqiT.
ATM qselebi organizebulia iseve
,
rogorc tradiciuli MAN
-
is tipis qselebi, kabelebisa da komutatorebis meSveobiT. ATM qselebis mier miRebuli siCqareebia 155
mbit/wm
da 622
mbit/wm Semdgom
Si ramodenime gigabitamde gazrdis SesaZleblobiT. 155
Mbps siCqare
SeirCa imis gamo, rom es aris si
Cqare
, romelic saWiroa sateleviz
io mo
nacemebisaTvis.
ufro zustad es siCqare iqna SerCeuli AT&T
-
sa da SONET
-
is urTierTSeTavsebisaTvis. 622
Mbps
ki SeirCa im mosazrebiT rom oTxma arxma SeZlos monacemebis gadacema misi meSveobiT.
ATM –
is SemuSavebis dros mTeli yuradReba gadatanili iyo videos Se
mo
Tavazebaze momxmareblisaTvis da satelefono sistemebis Secvlaze. heterogenuroba
-
nebismieri msxvili gamomTvleli qselis ganuyofeli Tvisebaa. sistemis sxvadasxva komponentebs Soris urTierTSeTanxmebaze administratorebi TavianTi drois did nawils xarjaven. g
adacemis asinqronul reJimis
teqnologia (
Asynchronous Transfer Mode ATM
) SemuSav
da
,
rogorc erTiani universaluri transporti qselebis axali TaobisaT
vis integrirebuli momsaxureobebi
T
, rom
lebsac agreTve ewodebaT farT
ozoliani
qselebi ISDN (Broadband
-
ISDN, B
-
ISDN
).
erTgvarovneba romelic ATM
-
ma unda uzrunvelyos SemdegSi mdgomareobs
imaSi, rom erTma satransporto teqnologiam unda uzrunvelyos ramodenime qvemoT CamoTvlili SesaZleblobebi.
·
nebismieri saxis, rogorc
kompiuteruli
aseve
multimediuri
trafikis
(xma, video
, m
arTva realur reJimSi
)
. sadac
yoveli
saxis trafikisaTvis
momsaxurebis xarisxi (
QoS –
Quality of Service
)
mis moTxovnebs unda Seesabamebodes.
·
monacemTa gadacemis siCqareTa ierarqia aTeulobiT megabitidan ramodenime gigabitamde wamSi
garantirebuli gamtar
unaria
nobiT
mniSvnelovani programebisaTvis
.
·
fizikuri arxebis arsebuli infrastruqturisa da fizikuri gamoyenebis sesaZlebloba
(PDH, SDH, maralsiCqariani
LAN)
8
·
urTierTqmedeba lokaluri da globaluri qselebis arsebul protokolebTan:
IP, SNA, Ethernet, ISDN
.
gadacemis asinqronuli reJimis
teqnologiis mTavari idea sakmaod adre gamoiTqva es termini SemoiRo laboratoriam Bell Labs
jer kidev 1968 wels. ZiriTadi ganviTarebadi teqnologia maSin iyo
TDM
teqnologia sinqronuli komutaciis meT
o
diT, is dafuZnebuli iyo
baitis rigobiT n
omerze gaerTianebul kadrSi.
TDM teqnologiis, romelsac aseve uwodeben sinqronuli gadacemis teqnologias STM (Synchronous Transfer Mode
) mTvari nakli mdgomareobs imaSi rom mas ar SeuZlia gadaanawilos gaerTianebuli arxis gamtarianoba qvearxebs Soris. drois im
periodebSi, rodesac qvearxis meSveobiT ar gadaicema momxmareblis monacemebi, gerTianebuli arxi mainc gadascems am qvearxis baitebs romlebic nulebiT aris Sevsebuli.
ATM
teqnologia aerTianebs or
teqnologi
as -
paketebis komutacias
a
da arxebis komutacias. pi
rvelisgan man aiRo monacemTa gadacema damisamarTebuli paketebis saSualebiT, xolo meorisagan
-
virtualuri arxebis teqnologia da patara, fiqsirebuli zomis paketebis gamoyeneba. yovelive amis Sedegad dayovne
beb
i qselSi ufro prognozirebadi xdeba. miuxedavad im
isa rom virtualuri arxebis teqnikis daxmarebiT, aseve arxis momsaxurebis parametrebis winaswari SekveTiT da virtualuri arxebis prioritetuli momsaxure
o
biT SeiZ
leba miRweul
iqnas arT qselSi sxvadasxva saxis monacemebis gadacema diskriminaciis gareSe. marTali
a
ISDN qselebi aseve muSavdeboda igive miznebisaTvis xmovani trafiki aSkarad prioritetuli iyo.
ATM teqnologia ki Tavidanve muSavdeboda rogorc teqnologia, romelic sxvadasxva saxis trafiks
maTi miTxovnebis Sesabamisad moemsaxureboda.
ATM teqnologiis Ziri
Tadi principebi
ATM
-
s gaaCnia msxvili qselebisaTvis damaxasiaT
ebeli klasikuri struqtura
-
saboloo sadg
urebi individualuri arxebiT uerT
deba qveda donis komutatorebs, romlebic Tavis mxriv, uerTdebian SedarebiT maRali donis komutatorebs. ATM
-
is
komutatorebi, marSrutizaciisaTvis saboloo kvanZebis 20
-
baitiani misamarTebiT sargebloben virtualuri arxebis teqnologiaze dayrdnobiT. kerZo
ATM
-
is
qselebisaTvis arsebobs marSrutizaciis protokoli PNNI (Private 9
NNI)
,
romlis meSveobiTac komutatorebs SeuZliaT Seqmnan marSrut
izaciis cxrilebi avtomaturad.
ATM standarti
ar sTavazobs Tavis
specifika
ciebs
fizikur
i
donis
realizaciisaTvis, aramed is eyrdnoba SDH/SONET
teqnologiebs da iRebs misgan
siCqareebis ierarqias. aqedan damomdinare, momxmareblis qselSi wvdomis sawyisi siCqare
tolia Sesabamisad
STM
-
1
–
155
mbit/wm
. ATM
-
is
magisraluri aRWurviloba ufro maRal siCqarezec muSaobs
: STM
-
4 -
622 mbit/wm
da STM
-
16 -
2,5 gbit/wm
.
garda amisa, ATM
-
is sxva mowyobilobebi muSaoben PDH
-
is
siCqareebze, rogoricaa 2 an 34/45 mbit/wm.
ATM teqnol
ogiaSi realizebuli moTxovna gamoixateba SedegSi: nebismieri zomis trafikis
-
kompiuteruli, satelefono Tu video gadacema fiqsirebuli da Zalian mcire sigrZis 53 baiti paketebiT. ATM
-
is paketebs ujredebs uwodeben. ujredis monacemTa veli ikavebs 48 baits, Tavs
arTi 5 baits. trafikis klasi (aseve ewodeba momsaxurebaTa servise class
) axasiaTebs qselSi monacemTa gadacemis saWiro moTxovnebs. Tu aplikacia
miuTiTebs, rom saWiroa magaliTad gadaices xmovani trafiki, aqedan naTeli xdeba, rom momxmareblisaTvis gansakuTr
ebiT mniSvnelovani iqneba iseTi maCveneblebi, rogoricaa dayovneba da ujredTa dayovnebis variaciebi. es arsebiT gavlenas axdens gadacemuli informaciis xmisa da gamosaxulebis xarisxze, xolo calkeuli ujredis dakargva arc ise mniSvnelovania, radgan xmis aRmdge
n mowyobilobas Se
uZlia gauwios mas aproqsimacia.
am dros xarisxi mxolod umniSvnelod zaraldeba. gadacemuli monacemebis sinqronizaciis moTxovna Zalian mniSvnelovania mravali aplikaciisaTvis
_ aramxolod xmis, aramed videogamosaxulebisac. am moTxovnebis arsebo
ba gaxda pirveli kriteriumi imisaTvis, rom trafiki dayofiliyo klasebad. trafikis sxva mniSvnelovani parametri, romelic gavlenas axdens qselSi mis gadacemaze, aris pulsacia. ATM teqnologiis Semqmnelebma gadawyvites am parametrTa mimarTebaSi gamoeyoT ori s
xvadasxva tipis trafiki. trafiki mudmivi bituri siCqariT (
Constant Bit Rate, CBR) da trafiki cvladi bituri siCqariT (Variable Bit Rate, VRB).
sxvadasxva klasebs miakuTvnes aplikaciiT
miR
e
buli trafikebi, romlebic Setyobinebebis gadasacemad iyeneben protok
olebs SeerTebis damyarebiT da SeerTebis damyarebis gareSe. pirvel SemTxvevaSi monacemebi gadaicema aplikaciebiT
sakmaod saimedod, rogorc es Cveulebriv xdeba protokolebSi SeerTebis damyarebiT. amitom ATM
-
sagan maRali saimedooba ar moiTxoveba. meore 10
SemTxvev
aSi danarTi muSaobs kavSiris damyarebis gareSe da damaxinjebuli Tu dakarguli monacemebis aRdgenas ar axdens. yovelive es uyenebs maqsimalur moTxovnebs ATM
-
is qselSi ujredebis gadacemis saimedoobas. sabolood gamoiyo trafikis xuTi klasi, romlebic gansxvavdeb
ian xarisxis Semdegi maxasiaTeblebiT: ·
trafikis pulsaciis arseboba an ararseboba CBR
an VBR;
·
monacemTa sinqronizaciis moTxovna gadamcem da mimReb mxareebs Soris.
·
protokolis tipi, romelic gadascems Tavis monacembs ATM
qselis saSualebiT –
kavSiris damyarebiT
an kavSiris damyarebis gareSe;
trafikis klasi
maxasiaTeblebi
A
m
udmivi bituri siCqare –
Constant Bit Rate, CBR
moiTxoveba drebiTi urTierTqmedeba gadacemul da miRebul m
o
necemebs Soris
kavSiris damyarebiT
magaliTebi: xmovani trafiki, satelevizio ga
mosaxulebis trafiki
B
cvladi bituri siCqare –
Variable Bit Rate, VBR
moiTxoveba drebiTi urTierTqmedeba gadacemul da miRebul mnecemebs Soris
kavSiris damyarebiT
magaliTebi:
kompresirebuli xma, kompresirebuli vide
o gamosaxuleba
C
cvladi bituri siCqar
e –
Variable Bit Rate, VBR
ar moiTxoveba dr
o
ebiTi urTierTqmedeba gadacemul da miRebul m
o
necemebs Soris
kavSiris damyarebiT
11
magaliTebi: kompiuteruli qselebis trafiki, romlebSic saboloo kvanZebi muSaoben kavSiris damamyarebeli protokolebiT: frame rela
y, X.25, LLC2, TCP
D
cvladi bituri siCqare –
Variable Bit Rate, VBR
ar moiTxoveba drebiTi urTierTqmedeba gadacemul da miRebul mnecemebs Soris
kavSiris damyarebis gareSe
magaliTebi: kompiuteruli qselebis trafiki, romlebSic saboloo kvanZebi muSaoben p
rotokolebiT kavSiris damyarebis gareSe (
IP, Ethernet, DNS,SNMP
)
X
t
rafikis tipi da misi parametrebi ganisazRvreba momxmareblis mier.
naTelia rom mxolod xarisxis maxasiaTebli, romlebsac trafikis klasi gansazRvravs, sakmarisi ar aris saWiro moTxovnebis a
rwerisaTvis.
ATM teqnologiaSi trafikis yvela klasisaTvis gansazRvrulia parametrebi. magaliTad A klasis trafikisaTvis aucilebelia miTiTebuli iqnas mudmivi siCqare, romliTac danarTi gadascems monacemebs qsels, xolo B klasisaTvis maqsimaluri arsebuli siCqare,
saSualo siCqare da maqsimaluri arsebuli pulsacia.
ATM teqnologia mxars uWers qvemoT moyvanil, ZiriTad raodenobriv parametrebs:
·
Peak Cell Rate (PCR) –
ujredebis
gadacemis maqsimaluri siCqare;
·
Sustained Cell Rate (SCR) –
ujredebis
gadacemis saSualo siCqare
;
·
Minimum Cell Rate (MCR) –
ujredebis
gadacemis minimaluri siCqare
;
·
Maximum Burst Size (MBS) –
pulsaciis maqsimaluri sidide;
·
Cell Loss Ratio (CLR) –
dakarguli ujredebis wili;
·
Cell Transfer Delay (CTD) –
ujredebis gadacemis dayovneba
;
·
Cell Delay variation (CDV) –
ujredebis dayovnebis variacia.
siCqareTa parametrebi ujredebSi izomeba w
amebSi
, pulsaciis maqsimaluri zoma –
ujredebSi, drois parametrebi –
wamebSi
. pulsaciis maqsimalur zomas gansazrvravs ujredebis raodenoba, romlebic danarTs SeuZlia gadasces maq
simaluri siCqariT
,
Tu 12
siCqare saSualoa. dakarguli ujredebis wili warmoadgens dakarguli ujredeb
is raoden
obas, mocemuli virtualuri SeerTebiT gagzavnili ujredebis saerTo raodenobasTan mimarTebaSi. ATM t
eqnologiaSi miRebilia terminis “momsaxurebis xarisxi” (
QoS
) aratradiciuli ganmarteba. Cveulebriv, traf
ikis momsaxurebis xarisxi xasiaTdeba gamtarunarianobis
parametrebiT
(am SemTxvevaSi RCR, SCR, MCR, MBS
),
paketebis dayovnebis parametrebiT
(
CTD da
CDV), aseve paketebis gadacemis saimedoobis parametrebiT (CLR
). ATM teqnologiaSi gamtarunari
obis maxasiateblebs trafikis parametrebs uwodeben da maT momsaxurebis xarisxis (QoS)
parametrebSi ar Tvlian.
QoS parametrebs ATM teqnologiaSi warmoadgenen mxolod CTD, CDV da
CLR parametrebi.
zog SemTxvevaSi danarTis specifik
a iseTia rom misi trafiki SeuZlebelia oTxi standartidan romelimes miekuTvnos. aseTi SemTxvevisaTvis SemuSavebulia kidev erTi X klasi, romesac ara aqvs aranairi damatebiTi aRwera, damTlianad ganisazRvreba im raodenobrivi parametrebiT da
QoS , romlebic g
anxilulia trafik
-
kontraqtSi.
ATM protokolebis steki
AMT protokolebis steki naCvenebia qvemoT moyvanil
nax.....
-
ze, xolo protokolebis ganawileba kvanZebsa da komutatorebze mocemulia nax...
-
ze.
AMT protokolebis steki
Seesabameba ISO/OSI
-
is qveda doneebs
da moicavs AMT adaptaciis dones, sakuTriv AMT dones da fizikur dones. pirdapiri Sesabamisoba AMT teqnologiis doneebis p
rotokolebs
a da OSI modelis doneebs Soris ar arsebobs.
13
nax. ATM protokolebis stekis struqtura
nax. protokolebis
ganawileba ATM
qselis protokolebsa da kvanZebs Soris
AMT protokolebis steki Seesabameba OSI/ISO modelis qveda doneebs da moicavs ATM adaptaciis dones, sakuTriv ATM
dones da fiz
i
ku dones. pirdapiri Sesabamisoba
AMT
teqnologiis protokolebsa da OSI modelos doneebs Soris ar aris.
14
adaptaciis done
AAL
adaptaciis done (
ATM Adaptation Layer, AAL
) warmoadgens AAL1
-
AAL5
protokolebis nakrebs, romlebic gardaqmnian ATM qselis zeda donis protokolebidan miRebul monacemebs ATM qselisaTvis saWiro formatis mqone ujredebad.
A
AL donis yoveli protokoli amuSavebs momxmareblis gansazRvruli klasis trafiks. standartizaciis sawyis etapze trafikis yovel klass Seesabameboda
AAL
-
is gansazRvruli protokoli magram ATM
-
is standartebis ganviTarebam aseTi damokidebileba Secvala da dReisaTvis erTidaimave
klasis trafikisaTvis sxvadasxva protokolebis gamoyeneba.
adptaciis done Sedgeba ramodenime qvedonisagan. AAL
-
is qveda dones ewodeba standartizaciisa da reasamblirebis qvedone (
Segmentation and reassembly, SAR
). es nawili ar aris damokidebuli
A
AL
protokolis tipze. is yofs monacemebs (axdens maT segmentacias), romlebsac ATM
iRebs zeda donis protokolebisgan
, ATM
ujredebad. saTaurebs mianiWebs maT da gadascems ATM
qselSi gasazavnad.
AAL
-
is zeda qvedones konvergenciis qvedones uwodeben (
Convergence Sublayer, CS ). es qvedone damokidebulia gadacemuli trafikis klasze. konvergenciis qvedonis protokoli Semdeg movaleobebs asrulebs: uzrunvelyofs droebiT sinqronizacias gadamcem da mimReb kvanZebs Soris, akontrolebs SesaZlo bitur Secdomebs momxmareblis infor
maciaSi da akontrolebs gadacemuli paketis mTlianobas.
AAL
protokolebi TavianTi samuSaos Sesasruleblad iyeneben samsaxurebriv informacias, romelic ganTavsebulia
AAL
donis saTaurebSi. virtualuri arxiT mosuli ujredebis moRebis Semdeg AAL
protokolis SAR qvedon
e agrovebs qselSi gaSvebul sawyis informacias
AAL
saTaurebis daxmarebiT , romlebic
ATM komutatorebisaTvis gamWvirvaleni arian. amis mizezia maTi ganTavseba ujredebis 48
-
bitian monacemTa velSi, swored ise rogorc zeda donis protokolebs moeTxovebaT. sawyisi m
onacemis damuSavebis Semdeg
AAL
awarmoebs saTauris samuSao vels da
AAL
kadris daboloebas. yovelive amis safuZvelze iRebs gadawyvetilebas miRebuli informaciis koreqtulobaze.
AAL
-
s
arcerTi protokoli momxmareblis monacemebis gadacemis dros ar aRadgens damaxi
njebul an dakargul monacemebs. AAL maqsimum Seatyobinebs saboloo kvanZs am paqtis 15
Sesaxeb. dakarguli monacemis aRdgena zeda donis protokolebis movaleobaa. isini ar Sedian ATM teqnologiis protokolebis stekSi. AAL1 protokoli emsaxureba A klasis trafiks mu
dmivi bituri siCqariT (
Constant Bit Rute CBR
) romlisTvisac damaxasiaTebelia cifruli video da is mgrZnobiarea droebiTi dayovnebebis mimarT. AAL1
-
is saTauri ATM
-
is ujredSi ikavebs erT an or baits. Sesabamisad momxmareblis monacemebisaTvis tovebs 47 an 46 bai
ts. saTaurSi erTi baiti gamoyofilia ujredis nomrisaTvis. amiT mimRebi mxare xvdeba ujredis mTliani Semcveloba mivida masTan Tu ara. xmovani trafikis gagzavnis dros yoveli Semdgomi nakadi misdevs winamorbeds 125 Ms, amitom ujredis dakargvis SemTxvevaSi Sei
Zleba drois koreqtireba Tu momdevno ujreds gadavwevT 125X46 raodenobiT. ramodenime baitis dakargva arc ise mniSvnelovania, radgan, mimRebi kvanZis xmis aRmdgeni mowyobiloba asworebs signals. AAL1 protokolis mizania daniSnulebis kvanZSi monacemTa ujredebis miRebisas araerTgvarovnebis gasworeba. AAL2 protokoli SemuSavebuli iyo B
klasis trafikis gadasacemad, magram standartebis ganviTarebam misi stekidan amoReba gamoiwvia. dResdReobiT B klasis trafiki AAL1, AAL3/4 da
AAL5 protokolebis daxmarebiT gadaicema. AAL3/4 protokoli amuSavebs pulsirebul trafiks –
Cveulebriv damaxasiaTebeli lokaluri trafikebisaTvis –
cvladi bituri siCqariT (
Variable Bit Rate, VBR
). es trafiki ise musavdeba rom ujredebis dakargva ar moxdes, magram ujredebi SeiZleba dayovndes komutat
oris mier. AAL3/4 protokoli asrulebs SecdomaTa kontrolis rTul proceduras. ujredebis gadacemis dros no,ravs sawyisi Setyobinebis yvela nawils da aRWuravs yovel ujreds sakontrolo jamiT. Tumca ujredis damaxinjebis an dakargvis SemTxvevaSi es done ar aRadgen
s maT, aramed gadayris yvela Setyobinebas anu yvela darCenil Setyobinebas, radgan kompiuteruli trafikis an kompresirebuli xmisaTvis monacemTa nawilis dakargva fatalur Secdomas warmoadgens. AAL3/4 protokoli AAL3 da
AAL4 protokolebis Serwymis Sedegia. isi
ni moqmedebebis logikis siaxlovis gamo gaaerTianes.
AAL5 protokoli
AAL4 protokolis gamartivebul saxes warmoadgens da ufo swrafadac muSaobs. is gamoiTvlis sakontrolo jams ara saTiTaod Setyobinebis ujrebisaTvis, aramed mTliani sawyisi SetyobinebisaTvis da aTavsebs mas Setyobinebis ukanasknel ujredSi. Tavdapirvelad AAL5 protokoli
SemuSavebuli iyo kadrebis gadasacemad frame relay, magram dResdReobiT igi gamoiyeneba AAL5 protokols SeuZlia uzrunvelyos xarisxis sxvadasxva parametrebi, amitom igi Cveulebriv gamo
iyeneba yvela im saxis trafikisaTvis, romlebic 16
mikuTvnebian kompiuteruli monacemebis gadamcemebs anu C da D klasebs. AAL5 protokoli
muSaobs ara mxolod saboloo kvanZebSi, aramed qselis komutatorebSi.
arsebobs gansazRvruli interfeisi danarTs, romlisTvisa
c saWiroa gadasces monacemebi ATM qselSi da adaptaciis done AAL
-
s Soris. am interfeisis daxmarebiT danarTi ukveTavs saWiro moTxovnebs, gansaZRvravs trafikis tips, mis parametrebs da QoS parametrebs. ATM teqnologia QoS parametrebis gansazRvrisaTvis or varia
ns uSvebs. pirveli _ maTi SekveTa uSualod danarTis mier da meore _ maTi daniSvna ,,siCumiT”, trafikis tipis mixedviT. ukanaskneli meTodi amartivebs masze momuSaveebis amocanas, radgan am SemTxvevaSi ujredebis miRwevis maqsimaluri Seferxeba da SeferxebaTa
variaciebi gadadis mTlianad qselis administratoris mxrebze. AAL
-
is
protokolebs ar SeuZliaT damoukideblad uzrunvelyon trafikisaTvis saWiro parametrebi. trafik
-
kontraqtis gansaxorcieleblad saWiroa qselis komutatorebis SeTanxmebuli muSaoba mTeli virtualuri
kavSiris gaswvriv. am samuSaos asrulebs ATM protokoli.
ATM protokoli
ATM protokolis ujredis formati mocemulia Semdeg naxazze:
Nnakadis marTva (
FGS
)
virtualuri gzis identifikatori (
VPI
)
virtualuri gzis (gagrZeleba)
identifikatori
virtualuri arxi
s identifikatori (
VCI
)
17
virtualuri arxis identifikatori (gagrZeleba)
virtualuri arxis identifikatori (gagrZeleba)
monacemTa tipebi (
PTI
)
P
aketis dakargvis prioriteti
Secdomebis marTva
saTaurSi (
HEC
)
Ppaketis monacemebi
nakadis marTvis veli (
Generic Flow Control, GFC
) gamoiyeneba mxolod saboloo kvanZis qselis pirvel komutatorTan urTierTqmedebis dros. am droisaTvis misi zusti funqcia gaurkvevelia.
virtualuri gzis identifikatori (Virtual Path Identifier, V
PI
) da virtualuri arxis identifikatori (Virtual Channel Idenifier, VCI)
ikaveben 1 da 2 baits. es velebi iZlevian virtualuri SeerTebis nomers, romelic gayofilia ufros (
VPI
) daumcros (VCI) nawilebad.
monacemTa tipis identifikatoris veli (
Payload Type Ident
ifier, PTI)
Sedgeba 3 bitisagan da gansazRvravs monacemTa tips, romelic ujredis mier gadaicema
-
momxmareblis an mmarTveli. amas garda am vels erTi biti gamoiyeneba qselis gadatvirTvis saCveneblad
-
mas 18
ewodeba Explicit congestion Forward identifier, EFCI da
TamaSobs igive rols
rasac FECN, frame relay qselSi. kadris dakatgvis prioritetis veli (Cell Loss Priority, CLP),
imave rols TamaSobs rasac DE
veli frame relay qselSi anu masSi komutetorebi niSnaven ujredebs, romlebnac daarRvies SeTanxmeba, xarisxis para
metrebis Sesaxeb. es moniSvna xdeba imisaTvis rom qselis gadatvirTvis SemTxvevaSi ganadgurdnen. amgvarad
CLP=0 veliT arian maRalprioritetuli, xolo CLP=1 dabalprioritetuli.
saTaurSi Secdomebis marTvis veli (
Header Error Control, HEC
) Seicavs ujredis saTaur
isTvis gamoTvlil jams. sakontrolo jami gamoiTvleba kodebis kireqtirebis hemingis meTodiT. am meTodiT SeiZleba Secdomebis povna. da ara mxolod erTeulovani Secdomebis gasworeba aramed zogierTi orobiTisac. HEC veli poulobs kadrebos dawyebis sazRvars bitur nak
adSi, romlebic ATM
teqnologiis fizikur dones ganekuTvnebian. SONET/SDH
teqnologiaSi maCveneblabi, romlebic saSualebas miscemdnen STS
-
n monacemTa kadrSi ujredebis sazRvrebi daedginaT ar arsebobs. amitom ATM komutatori iTvlis sakontrolo jams 5 baitidan, roml
ebic ganTavsebulni arian STM
-
n
kadris monacemTa velSi. Tu gamoTvlili jami saTauris koreqtulobaze metyvelebs, maSin pirveli baiti ijredis saTauri xdeba. Tu es ase ar aris, maSin xdeba erTi baitiT daZvra da operacia grZeldeba. amgvarad ATM teqnologia gamoyof
s asinqronul nakads SDH sinqronul kadrebSi an fizikuri donis bitebis nakadidan, romelic ujredebzea dafuZnebuli.
ganvixiloT ATM ujredebis kimutaciis meTodi ricxvebis wyvilzw dayrdnobiT. ATM komutatorebs SeuZliaT or reJimSi muSaoba, esenia: virtualuri gzis komutacia da virtualuri arxis komutacia. pirvel SemTxvevaSi komutatori ujreds Zravs mxolod VPI dayrdnobiT da ugulebelyofs
VCI vels.
uredis miRwevis Semdeg
ATM lokalur qselSi komutatori iwyebs mis komutacias rogorc
VPI aseve
VCI velebze dayrdnobaT, magram
amasTan komutaciisaTvis sakmarisia virtualuri nomris umcrosi nawili. amgvarad komutatori faqtiurad VCI velTan musaobs, xolo VPI ucvleli rCeba. swore des aris virtualuri arxis komutaciis reJirimi.
sakomutacio virtualuri arxis Seaqmnelad ATM
teqnologiaSi g
amoiyeneba protokolebi romlebic zemoT moyvanil naxazze ar aris naCvenebi. kavSiris dasamyareblad SemuSavebulia Q.2931
protokoli, romelic Tavisuflad SeiZleba mivakuTvnoT qselur dones. Q.2931 19
protokoli eydnoba sakmaod rTul SSCOP protokols, romelic uzrunvelyo
fs Q.2931 paketebis saimedo gadatanas Tavis kadrebSi. Tavis mxriv SSCOP protokoli AAL5 protokolze maRla muSaobs. es ukanaskneli saWiroa SSCOP kadrebis ATM ujredebad dasayofad, Semdeg ki maTi xelaxli SesakrebisaTvis SSCOP kadrebad. virtualuri kavSiri romel
ic myardeba SSCOP protokolis daxmarebiT SeiZleba iyos simpleqsuri (erTmimartulebiani) da dupleqsuri.
Q.2931 protokoli aseve “ erTi
-
erTTan” (
poin
-
to
-
point
) da ,,erTi mravalTan” (
poin
-
to
-
multipoint
) tipis virtualur kavSirebis damyarebis saSualebas iZleva.
saboloo kvanZis misamarTi ATM komutatorebSi 20baitiania. mas SeiZleba saxvadasxvanairi formati hqondes. sazogado qselebSi gamoiyeneba E164
standartis misamarTi amasTan, 1 baits Seadgens AFI, 8 baits ikavebs IDI -
E164 ZiriTadi nawili (satelefono nomrai
s 15 cifri) danarCeni
DSP
-
s
(Domain Spesfic Part ) 11 baiti ganawilebulia Semdegnairad:
·
DSP ufrosi veilis 4 baits ikavebs -
Higt
-
Order Domain Spesific Part (HO
-
DSP
), romelic arsebiTad warmoadgens qselis nomers. igi SeiZleba nawilebad daiyos marSrutizacii
s agregirebisaTvis, PNNI protokolis mixedviT.
·
6 baits ikavebs saboloo sistemis identifikatoris veli –
End System Identifier (ESI
), romelsac
ATM kvanZSi MAC misamarTis mniSvneloba aqvs.
·
1 baits Seadgens struqturis veli, romelic ar gamioyeneba virtualuri ar
xis dayenebis dros. mas kvanZis lokaluri daniSnuleba aqvs.
kerZo qselebSi ATM Cveulebriv gamoiyenebs misamarTis formats, romelic Seesabameba saerTaSoriso organizaciebis (am SemTxvevaSi ATM Forum
) domens. am SemTxvevaSi IDI ikavebs 2 baits, romlebic Seicav
en ATM Forum
-
is kods, darCenili nawili ki Seesabameba zemoTaRweril struqturas, im gansxvavebiT, rom DSP ikavebs ara 4, aramed 10 baits. ESI
misamarTi saboloo kvanZs eniWeba damamzadebeli sawarmos mier. IEEE wesebze dayrdnobiT, anu pirveli 3 baiti Seicav
s mwarmoeblis kods, Semdegi 3 aris rigobrivi nomeri dam is unikalurobaze pasuxismgebelia mwarmoebeli. saboloo kvanZi ATM komutatorTan SeerTebiT asrulebs e.w.registraciis proceduras. is atyobinebs komutators Tavis ESI misamarTs. komutatori atyobinebs mas misamarTis ufros nawils anu qselis nomers, romelSic kvanZi muSaobs.
20
samisamarTo nawilis garda Q.2931
protokolis CALL SETUP paketi Sedgeba
nawilebisagan, romlebic aRweren trafikis parametrebs da
QoS moTxovnebs. aseTi paketis miRebis Semdeg komutatorma und
a gaanalizos es parametrebi da gadawyvitos gaaCnia Tu ara sakmarisi Tavisufali resursebi axali virtualuri kavSiris momsaxurebisaTvis. Tu gaaCnia komutatori gadascems CALL SETUP
pakets daniSnulebis misamarTis da marSrutizaciis cxrilis Sesabamisad, xolo Tu ar gaaCnia moTxovna uaryofilia.
ATM momsaxurebeTa kategoriebi da trafikis marTva
ATM
protokolis doneze sul xuTi momsaxurebaa:
·
CBR –
momsaxureba trafikisaTvis mudmivi bituri siCqariT;
·
rtVBR –
momsaxureba cvladi bituri siCqaris trafikisatvis, romelic moi
Txovs saSualo siCqaris SenarCunebas, wyarosa da momRebis sinqronizacias;
·
nrtVBR -
momsaxureba cvladi bituri siCqaris trafikisatvis, romelic ar moiTxovs saSualo siCqaris SenarCunebas, wyarosa da momRebis sinqronizacias;
·
ABR -
momsaxureba cvladi bituri siCq
aris trafikisatvis, romelic moiTxovs monacemTa gadacemis minimaluri siCqaris SemarCunebas da ar moiTxovs sinqronizacias.
·
UBR –
momsaxurebe trafikisa, romelic ar uyenebs moTxovnebs arc siCqares da arc sinqronizacias.
CBR kategoriis momsaxurebebi gankuTvnil
ia trafikisaTvis sinqronuli danarTebiT. rodesac danarTi amyarebs CBR kavSirs, is ujredebis pikur PCR siCqares ukveTavs. es aris maqsimqluri siCqare romlis drosac ujredebis da
QoS
parametrebis dakargvis riski ar arsebobs.
Semdeg monacemebi igzavneba am da
nyarebuli kavSiriT gadaicema. yoveli ujredi, romelic sadguris mier didi siCqariT igzavneba aRniSnulia CLP=1 niSniT. qselis dagatvirTvis SemTxvevaSi es ujredebi SeiZleba ubralod gadagdebuli iqnas qselis mier. ujredebi romlebic igvianeben aseve dabali priori
tetiT gamoiyofian CLP=1.
CBR momsaxurebasTan SedarebiT VBR momsaxureba iTxovs
ufro rTul procedurebs qselsa da danarTs Soris kavSiris dasamyareblad. pikuri PCR
siCqaris garda danarTi iTxovs kidev or parameters: mudmiv siCqares SCR da pulsaciis maqsimalur zomas MBS. momxmarebels SeuZlia gazardos siCqare PCR
-
mde, magram mxolod mcire periodiT, 21
romlis ganmavlobaSic gadaicema monacemebi, romelTa mniSvnelobebi ar aRemateba MBS
-
s
. am periods pulsaciis mimarT mdgradoba (
Burst Tolerance, BT
) ewodeba.
Tu PCR siCqar
e BT periodze didxans grZeldeba vaSin ijredi itvleba damrRvevad da eniWeba
CLP=1.
rtVBR kategoriisaTvis kontrolirebadia igive CoS parametrebi, rac
CBR kategoriis SemTxvevaSi
, xolo
nrtVBR Semoifargleba trafikis parametrebis mxardaWeriT. trafikis paramet
rebisa da QoS
-
is kontrolirebisaTvis gamoyenebulia ujredebis siCqaris kontrolis gafarToebuli algoriTmi (
Generic Cell Rate Algorithm), romelsac SeuZlia iseTi parametrebis Semowmeba, rogoric aris: PCR,CDV,SCR,BT,CTD, da
CDV).
CBR da VBR
-
gan gansxvavebiT
UBR
ar iTvaliswinebs arc trafikis da arc mimsaxurebis xarisxis parametrebs. igi yovelgvari kontrolis gareSe muSaobs ,,SeZlebisdagvarad”. UBR
-
is mTavari naklia is, rom ar SeuZlia monacemTa nakadis marTva. imis gamo, rom UBR ar iTvaliswinebs QoS parametrebs, bu
feris gadavsebis SemTxvevaSi misi monacemebi pirvel rigSi amovardeba,
ABR momsaxureba UBR
-
is
msgavsia, magrea trafikis marTvis meqanizmis meSveobiT gadatvirTvis SemTxvevaSi is ujredebis senarCunebis garantias iZleva
. ABR kategoriis kavSiris damyarebis Sem
deg ABR moiTxovs PCR siCqares, magram SeTanxmeba ujredebis gadacemis Seyovnebis an pulsaciis parametrebis Sesaxeb ar xdeba. amis magivrad qseli da saboloo kvanZi Tanxmdebian gadacemis minimalur MCR siCqareze. es danarTis mcire gamtarobas uzrunvelyofs. sabo
loo kvanZi Tanxmdeba imaze, rom ar gagzavnis monacemebs PCR
-
ze maRali siCqariT, xolo qseli Tanxmdeba ujredebis gadacemisas uzreunvelyos minimaluri siCqare –
MCR. Tu Tavidan
minimaluri da maqsimaluri mniSvnelobebi miTiTebuli ar aris maSin, maTi ,,siCumiT” i
Tvleba, rom PCR emTxveva sadgurTan qselis miRwevis xazis siCqares. xolo MCR –
iTvleba nulad. ABR garantirebul xarisxs inarCunebs dakarguli ujredebis da gamtarobis mimarT. rac Seexeba Seferxebebs, ABR cdilobs maT minimizacias, magram garantias ver iZleva.
CBR, VBR da
UBR trafikebis gadacemis dros qselis gadatvirTvis marTva ar xdeba, xdeba damrRvevi ujredebis gadagdeba. ABR qselis gamrarobis rezervebiT sargeblobis saSualebas iZleva. is atyobinebs saboloo kvanZs mocemuli momentisaTvis arsebuli 22
gamtarobis dan
akliss ukukavSiris meSveobiT, am meqanizms SeuZlia daexmaros ABR
-
s monacemTa gadacemis siCqaris daklebaSi Tuki qseli gadatvirTulia.
kvanZma, romelic ABR momsaxurebiT sargeblobs, monacemTa ujredebTan erTad periodulad unda gaagzavnos qselSi muSa informacii
s Semcveli ujredebi, romlebic marTaven resursebs (
Resorce Manager RM
). RM ujredebs, romlebsac kvanZi gzavnis monacemTa nakadis gaswvriv, pirdapiri –
Forward
Resorce Manager
-
FRM
ujredebi
, xolo ujredebs, romlebic monacemTa nakadis sapirispiro mxares arian m
imarTulebi, ,,uku”
-
Bakward
Resorce Manager -
FRM
ujredebi ewodebaT. ukukavSiris ramdenime forma arsebobs. yvelaze martivi –
saboloo sadgurebs Soris ukukavSiria. misi arsebobis SemTxvevaSi komutatori atyobinebs saboloo sadgurs gadatvirTvis Sesaxeb specia
luri almis daxmarebiT (alami EFCI)
, is ganTavsebulia monacemTa ujredSi gadatvirTvis marTvi velSi. amis Semdeg saboloo sadguri agzavnis qselSi Setyobinebas ujredebis nakadis siCqaris Semcirebis Sesaxeb. es Setyobineba ganTavsebulia BRM
-
is marTvis specialur velSi. am meTods naklic aqvs: saboloo sadguri am Setyobinebidan ver igebs ramdeniT Seamciros siCqare. amotim is ubrslod minimumamde amcirebs mas. am meTodSi mTavar funqcias sabiloo kvanZi asrulebs.
arsebobs ufro rTuli sqemac sadac mTavar rols komutatori
asrulebs. pirvel SemTxvevaSi kvanZi wyaro agzavnis
FRM ujrediT monacemTa gadacemis siCqares. yvela komutatori romelsac, es Setyobineba gaivlis aklebs mas siCqares. daniSnulebis kvanZi mas gardaqmnis
BRM
-
ad da gzavnis warosTan. meore SemTxvevaSi yovel komu
tators SeuZlia imuSaos rogorc wyarom da rogorc mimRebma.
ATM teqnologiaSi ganxorcielebulia trafikis prioritetuli momsaxurebis strategia. Tavidan CBR
-
s moeniWeboda pirveli prioriteti, VBR
-
s meore, xolo UBR
-
s mesame. es sqema ver imuSavebs
ABR
trafikTan. AB
R momsaxurebis realizaciisaTvis ATM komutatorebma
unda uzrunvelyon ordoniani sqema. am sqemis mixedviT komutetorebi Tavisi gamtaribis raRac nawils momsaxurebis yvela klass aZlevs: CBR iRebs gamtarobas
PCR
siCqaris SesanarCuneblad, VBR saSualo siCqaris Sesa
narCuneblad, ABR ki iRebs gamtarobis nawils ujredebis minimaluri siCqaris
MCR
uzrunvelsayofad. am 23
algoriTmis meore safexurze CBR
-
sa da VBR
-
s SeuZliaT aiRon qselis darCenili gamtaroba Tu amis saWiroeba iqneba, radgan ABR
-
ma
gamtarobis Tavisi nawili ukve mii
Ro.
daskvnebi
·
ATM teqnologia warmoadgens virtulauri arxis gamtarobis Tvisebis razervirebis ideis Semdgoni ganviTarebas, romelis realizebuli frame relay
teqnologiaSi.
·
ATM teqnologia inarCunebs trafikis ZiriTad tipebs, romlebic arsebobs sxvadasxa tipis abon
entebSi: trefiki mudmivi bituri siCqariT CBR , romelic aris damaxasiaTebeli satelefono da dagamcemi qselebisaTvis. trafiki cvladi bituri siCqariT VBR , damaxasiaTebelia kompiuteruli qselebisatvis, aseve kompresirebuli xmisa da gamosaxulebis gadasacemad.
·
ta
fikis yoveli tipisatvis mimxmarebels SeuZlia qsels SeukveTos xarisxis momsaxurebis ramodenime parametris mniSvneloba –
maqsimaluri bituri siCqaris PCR, saSualo bituri siCqare SCR, maqsimaluri pulsacia BBS, aseve gadamcemsa da mimRebs Soris droebiTi Tanafar
dobis kontroli rac mniSvnelovania Seferxebebis mimarT mgrZnobiare trafikisaTvis.
·
ATM teqnologia Tavad ar gansazRvravs fizikuri donis axal standartebs, igi iyenebs ukve arsebuls. ATM teqnologiis ZiriTad standarts qarmoadgens SONET/SDH da
PDH teqnologiis arx
ebis fizikuri done.
Автор
v.aslanishvili
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