20938555 Switch Basics 5ESS

7/27/2019 20938555 Switch Basics 5ESS

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5ESS EXCHANGE SYSTEM

Basic characteristics/Functions of the 5ESS-2000 Switch

Overview :-

The 5ESS-2000 Switch is a digital exchange that can serve as a local(lines)toll(trun!s) tande"(lines and trun!s) #S$S(o%erator Service $ositionS&ste") or international gatewa& exchange de%ending on the t&%e ofswitch' t can serve a s"all co""unit& with fewer than 00 su*scri*ers or alarge "etro%olitan area serving "ore than 00000 su*scri*ers'

Modular Distributed Desig :-

The 5ESS- 2000 switch is a digital switching with distri*uted %rocessing'+istri*uted %rocessing "eans that "ulti%le %rocessors handle all call

%rocessing functions' ,an& %rocessors are distri*uted throughout the s&ste"su%%orted *& a central %rocessor' These distri*uted %rocessors handlesecond-to-second decisions that "ust *e "ade to %rocess a call' all

%rocessing self "aintenance and testing are %erfor"ed inde%endentl& ineach "odule' $rocessors co""unicate with each other via an iteraldigital etwor! that lin!s the "odule together'

The 5 ESS 2000 Switch hardware has three "a.or t&%es of eui%"ent"odules'

"# SM $Swit%&ig Module'(# CM $Co))ui%atios Module'*# AM $Ad)iistrative Module'

Each "odule %erfor"s its assigned functions to contri*ute to the o%eration ofthe entire switch'

The SM connects all lines and trun!s to the 5 ESS-2000 Switch' t %erfor"s"ost of the call %rocessing functions' There can *e "an& S,s %er 5ESS-2000 Switch'

The CM %rovides co""unication *etween the S,s and the ,' There isone , %er 5ESS-2000 Switch'



The AM %rovides ad"inistration and "aintenance ca%a*ilities' There is one, %er 5ESS-2000 Switch'

Growt& ad Degrowt& :-

,odular architecture "a!es it eas& to increase or decrease the ca%acit& ofthe exchange' ncrease in the ca%acit& of the switch is called 1#3T4'+ecrease in the ca%acit& of the switch is called +E1#3T4'The S, is the %ri"ar& "odule for growth or +egrowth of the 5ESS-2000switching s&ste"' 1rowth or +egrowth is acco"%lished *& changing the no'of S,s in a switch or the no' of units within the S,s'

"# S+,TCH,NG MOD.E /NCT,ONS

Overview :-

ll external lines trun!s and s%ecial services c!ts' are ter"inated at theswitching "odule' The analog digital are converted to the digital for"atused inside the 5ESS-2000 Switch' The S, %erfor"s al"ost 657 of the call

%rocessing "aintenance functions including 8

•

9ine Trun! scanning• outine "aintenance self-"aintenance• Tone adence generation• +igit anal&sis• all routing• !t' Switching• $ac!et switching• nnounce"ents• all %rogress su%ervision

The S, %rovides "an& su*scri*er calling features including 8-

• all 3aiting• **reviated +ialing• all +iversion• onference alls



#ne 5 ESS-2000 Switch can su%%ort as "an& as 62 S,s' Each S, canhandle as de%endent u%on engg' considerations'

TY0ES O/ S+,TCH,NG MOD.ES

t can *e eui%%ed with the following t&%es of S,s 8-

A' .SM $.OCA. S+,TCH,NG MOD.E' :-

This t&%e of S, serves local lines trun!s S+: (ntegrated Services+igital :etwor!) users' The 9S, is usuall& referred to as the S,'

1' HSM $HOST S+,TCH,NG MOD.E' :-

This %rovides the nor"al 9S, su*scri*er interfaces also interfaces one or"ore S,s (e"ote Switching ,odules)'

C ' 2SM $2EMOTE S+,TCH,NG MOD.E' :-

This t&%e of S, is designed to "eet the needs of those co""unities that aretoo s"all to *e served *& their own 5ESS-Switch in a re"ote area' This isdone *& having the S, connected to an 4S,' The S, can *e as farawa& as 2;2!"s' Fro" the host u%to ; S,s (called a ,,S, (,ulti-

,od S,)) can *e interconnected to serve <000 lines 2000 trun!s or aco"*ination of line trun!s' The S, %rovides full - stand -aloneca%a*ilities including direct trun!s to other exchanges can *e usedsingularl& or grou%ed in clusters'

D ' 0SM $0OS,T,ON S+,TCH,NG MOD.E' :-

This t&%e of S,s su%%orts #S$S(#%erator Services $osition S&ste")features'

#riginall& the S,s were called ,s(nterface ,odules)'

S+,TCH,NG MOD.E COM0ONENTS



S,s consists of two t&%es 8 "# The single SMC$S+,TCH,NG MOD.E CONT2O..E2' is

nu"*ered and contains the control units that are assigned s%ecificlocations within the S,'

• CONT2O. N,TS :- t controls all activities within the S,s such asall $rocessing and "aintenance functions'

(# n S, can have fro" one to four .T0 $ .,NE3T2N40E2,0HE2A.' ca*inets that are nu"*ered

02= and ;'

•

0E2,0HE2A. N,TS :- t %erfor" testing function and %rovidecusto"ers and other exchanges access to the 5 ESS- 2000 Switch digitalnetwor!' There are two t&%es of %eri%heral units'

,ter6a%e its :- that interface %ac!et data analog and digital linesand trun!s to the 5 ESS-

2000 Switch'

Servi%e its :- that %rovide su%%ort as test eui%"ent and "ulti%ortconferencing circuits'

"' SM CONT2O. N,TS :-

9ocated in the S, ca*inets are the two S, control units 8-

a' T&e SM0$S+,TCH,NG MOD.E 02OCESSO2' 7

b' T&e TS,$T,ME S.OT ,NTE2CHANGE2'

These two units are co"*ined into the MCTS,$MOD.ECONT2O..E2 7 T,ME S.OT ,NTE2CHANGE' which is alsoreferred to as the ,T>'



a' S+,TCH,NG MOD.E 02OCESSO2 :-

The S,$ contains the "icro%rocessor and "e"or& used to %erfor" thecall %rocessing and "aintenancefunctions within the S,' The S,$ %erfor"s five "a.or functions 8

• ontrol $eri%heral >nits'• $erfor"s alls $rocessing'• $erfor"s S, "aintenance'• nitiali?es S, "e"or&'• o""unicates with the , and others S,s'

b' T,ME S.OT ,NTE2CHANGE2 :-

The second control unit in the S, is the TS(Ti"e Slot nterchanger)'The TS %erfor"s the ti"e %ortion of the ti"e-s%ace-ti"e divisionswitching' This t&%e of switching allows "ulti%le in%uts access to a setno' of out%uts when %rocessing %hone calls'

This TS trans"its and receives %eri%heral ti"e slots to fro" %eri%heral units' $eri%heral ti"e slots contain digital call data fro" linesand trun!s or other user data such as fro" co"%uters'

The TS also switches data fro" the networ! side to the , where it isrouted to other S,s'

The TS interchanges the %eri%heral ti"e slots to the networ! ti"e slotson two :T(:etwor! ontrol Ti"ing) lin!s connecting the S, to the,' n the reverse direction the TS also interchanges networ! ti"eslots to %eri%heral ti"e slots' The TS also interchanges %eri%heral ti"eslots *etween different %eri%heral units'

(' SM 0E2,0HE2A. N,TS :- t consists of the following 8

A' ,NTE2/ACE N,TS 1' 0AC4ET S+,TCH N,T C' SE28,CE N,TS

A' ,NTE2/ACE N,TS8-



T&ere are two aalog iter6a%e uits :-

a' .$.,NE N,T':- t connects analog lines fro" the su*scri*erstele%hones to the 5ESS- 2000

b' AT$ANA.OG T2N4 N,T' :- t ter"inates a variet& of analogtrun!s to the digital switching networ!' These voice fre' trun!s can *einterexchange trun!s trun!s to $B@s ($rivate Branch Exchange) trun!sto announce"ent "achine units or local test c!ts'

T&ere are ( digital iter6a%e uits :-

a' ,S.( $,NTEGE2ATED SE28,CES .,NE N,T MOD.E (' :-

t ter"inates *oth analog digital su*scri*er lines' The S9>2 iseui%%ed in S,s that have S+:(ntegrated Services +igital :etwor!) its %ri"ar& %ur%ose is to

%rovide service to the S+: su*scri*ers'

b' D.T $D,G,TA. .,NE T2N4 N,T' :-

t ter"inates digital trun!s fro" other exchanges or fro" S,facilities in a switch and convertsT or $, ($ulse ode ,odulation ) 2,*/s (,ega*it $er- Second)for"at to networ! ti"e slot for"at'

1' 0S$0AC4ET S+,TCH N,T' :-

t is a s%ecial interface unit that does not directl& ter"inate lines or

trun!s' The $S> %erfor"s several"iscellaneous S+: functions 8-

a) ' $rocesses T>-T( :TE:T#:9 TE9E#,,>:T#:>:#: TE9E#,>:T#: ST:++AT#: SET#)

:o' < signaling'



*) ' $rocesses %ac!et switched data'

C' SE28,CE N,TS 3 SE28,CE C4TS# :-

There are 5 t&%es of service units = of which are referred to as +S>s(+1T9 SECE >:TS)' The different t&%es are as follows 8-

a' .DS $.OCA. D,G,TA. SE28,CE N,T ' :-

t has two functions 8-

D To generate digital tones D To decode digital tones

The tones generated or decoded *& the 9+S> can *e routed to an& lineor trun! on a %articular S,' The 9+S> functionalit& can *e %rovidedin a variet& of eui%"ent configurations ranging fro" a fullunit to a single c!t' %ac!'

b' GDS $G.O1A. D,G,TA. SE28,CE N,T ' :-

Ever& 5ESS-2000 Switch has atleast one 1+S> which can %rovide

services to an& S, in theexchange' The 1+S> can also *e configured in a variet& of wa&s' The

1+S> has the following twofunctions 8-

D onference facilitiesD Trans"ission testing

%' DS( -2A/3 SAS $ D,G,TA. SE28,CE N,T ( - 2ECO2DEDANNONCEMENT /NCT,ON 3SE28,CE ANNONCEMENT

SYSTEM ' :-

t %rovides an announce"ent when a call is routed to a vacant code eui%"ent is *us& or *loc!ing conditions exist' #ther uses include#S$S features when custo"ised announce"ents are needed'SS has "ore announce"ent ca%acit& than its %redecessors F'



d' MMS $MOD.A2 META..,C SE28,CE N,T' also %alled asMS :-

t has = functions 8

D ,etallic test access D Su*scri*er line testing

D scan distri*ute function

e' 00M $0E2,OD,C 0.SE METE2,NG N,T ' :-

Su*scri*er lines used in coin*oxes hostels restaurants ver&often have a ho"e "eter installed 'These su*scri*ers are connected tothe $$,> ( or $$,> auxiliar&) which in.ects the correct signalling

to incre"ent the ho"e "eter %rovides the su*scri*er with anaccurate "easure of %hone usage '

(# COMMN,CAT,ON MOD.E /NCT,ONS

Overview :-

Because of the distri*uted %rocessing architecture of the 5ESS-2000 Switch

infor"ation "ust constantl& *e exchanged *etween %rocessors ' The ,(o""unications ,odule) serves as the hu* (focal %oint) for allinter"odule co""' in a 5ESS-2000 Switch ' COMMN,CAT,ON MOD.E /NCT,ONS :-

n the switch the , S,s are not directl& connected to each other' The, routes "essages *etween each "odule so the& all wor! together' The, has four "ain functions 8-

• all Switching 8 The , interconnects the %aths *etween switching"odules to co"%lete tele%hone calls and to rela& data'• ,essage Switching 8 The , %rovides %aths to send infor"ation

*etween %rocessors to %rocess calls "aintain records and %erfor"s&ste" tas!s'• :etwor! Ti"ing 8 The , %rovides accurate ti"ing ands&nchronisation for the 5 ESS-2000 Switch'



• Fast $u"% 8 The , %rovides resources to uic!l& download(%u"%)software fro" , to :S, if needed'

COMMN,CAT,ON MOD.E .,N4AGES : -

The , is connected to the , *& the +S4(+ual Serial hannel) *us'This "etallic *us has two serial *it strea"s that receive and rela& control"essages'

:T(:etwor! ontrol Ti"ing) lin!s are fi*re o%tic ca*les that connecteach S, to the ,' The :T lin!s carr& infor"ation in a "ax' of 52 ti"eslots divided *etween two %h&sical lin!s' #ne of the 25< ti"e slots on eachlin! is a dedicated control "essage ti"e slot'

Each of the control ti"e slots is used to carr& inter"odule control "essages'The other 255 ti"e slots %er lin! are used to carr& call data(voice sa"%les orcusto"er data trans"issions)'

:ot shown on the gra%hic the 9:(o""s' lin!) is the hardware %ath *etween the S,$ the ,S$>(,essage Switch $eri%heral >nit) of the ,'This is the %ath that carries the control ti"e slot' Because of the redundantnature of the , hardware each S, has alternate 9: %aths across theswitching networ!'

CM CA1,NET CON/,G2AT,ONS :- The , line-u% can var& in si?efro" a "ini"u" of two to a "ax' of twelve ca*inets that are grown fro" thecentre out in a "irror i"age' Basic ca*inets 5 < are alwa&s eui%%ed andde%ending on the nu"*er of S,s su%%orted additional ca*inets can *eadded two at a ti"e starting with growth ca*inets ; and '

MA9O2 COM0ONENTS O/ THE CM :-

ll versions of the , are divided into two functional units 8-

"' T&e MSGS $MESSAGE S+,TCH '( ' T&e ONTC$O//,CE NET+O24 AND T,M,NG COM0.EX'

The following descri%tion is *ased on the "ost co""on t&%e of ,currentl& in the field the ,2'



The ,S1S and #:T are each "ade u% of su*-units ' The four "a.orfunctions of the , are %erfor"ed *& these hardware su*-units 8

) MSGS :-

a ' MSC $Message Swit%& Cotrol it ' b ' MS0 $Message Swit%& 0eri&eral it '

( ' ONTC :-

a ' CMC $Co))ui%atios Module Cotrol it 'b ' TMS $Ti)e Multile;ed Swit%& it '

The #:T also includes so"e functional areas of the S,/ S,-2000

" ' MSGS

a' MSC :-

t %rovides control over the ,S$>' t %asses control infor"ation to fro" the , the other , units it also inter%rets the destination code of the control "essagesco"ing fro" the S,s ' The

,S> directs the infor"ation flow *etween %rocessors in the , the S,s '

b ' MS0 :-

t %rocesses control "essages switches the" to the , or S,s 'The ,S$> can *e regarded as a series of "ail *oxes in which "essages are de%osited *efore the& arerouted' Each S, has assigned ca%acit& in the ,S$> control "essages are transferred under

direction of the ,S> '

( ' ONTC

a' CMC :-



t %rovides ti"ing for the s&ste" %rovides control for the T,S( Ti"e ,ulti%lexed Switch )' t also %rovides the connection %ath *etween the T,S , ,S> ,S$>'

b' TMS :-

t ter"inates the :T lin!s switches *oth data control ti"e slots *etween the lin!s ' The hardware units of the T,S %erfor" the actual switching of the calls

*etween trun!s '

:o single unit of the , is "ore i"%ortant than the others ' Because

of the interconnecting %aths all the %arts are necessar& ' Because of this virtuall& all %arts of the, are du%licated '

TY0ES O/ COMMN,CAT,ON MOD.ES :-

There are four t&%es of ,s in the field 8-

" ' CM":- This was the earliest t&%e of , ' t o%erates "uch the sa"e as the

,2 *ut is of an older vintage ' t is "ade u% of a "ax' of ; ca*inets of eui%"ent ' t is ca%acit&li"ited (=2 S,s ) has *een

re%laced nearl& ever&where with ,2 '

( ' CM( :- ,ost co""on toda& the ,2 can su%%ort u% to 62 S,s or a "ix

of S,s S,-2000 ' t is "ade u% of a "in' of 2 ca*inets *ut can grow to as "an& as 2 when needed'

*' CM( +,TH <.0S $<AD .,N4 0AC4ET S+,TCH ' :-

This is a "odification of the ,2 which adds additional control"essage ca%acit& ' t is availa*le for offices with high ca%acit& S,-2000s' t is nearl& identical to the,2 with additional hardware units



added '

= ' CM(C :-

This unit is intended for s"all office a%%lications su%%orts onl& ali"ited no' of S,S ' t is "ade u% of a 2 shelves which can reside in an S, ca*inet '

* # ADM,N,ST2AT,8E MOD.E /NCT,ONS

O8E28,E+ :-

n the 5ESS-2000 Switch the , (d"inistrative "odule ) is a

switch eui%"ent "odule which hasthe overall control of the entire 5ESS- 2000 Switch ' The , controls

the , co""unicates withall the S,s (through the , ) ' The , "onitors itself and the ,

for "alfunctions '

ADM,N,ST2AT,8E MOD.E /NCT,ONS : -

t has a "in' of ca*inet can have a "ax' of = ca*inets ' The , %erfor"s resources allocation

%rocessing functions that are done "ore efficientl& on a centralised *asis such as 8-

• all routing for inter"odule intra"odule calls• d"inistrative data %rocessing/ *illing data• Traffic "easure"ent re%orts ( s&ste" %erfor"ance re%orts )• ,e"or& "anage"ent• S&ste" "aintenance• ,aintenance file records o f changes to the s&ste" software release•

$ersonnel interface / s&ste" "onitoring• llocating trun!s for call %rocessing

ADM,N,ST2AT,8E MOD.E COM0ONENTS :-



There are three "ain units located within the , 8-

G C $Cotrol it ' G ,O0 $,ut 3 Outut 0ro%essor '

G D/C $Dis! /ile Cotroller '

The C "onitors overall s&ste" o%eration '

The ,O0 interfaces with the , (,aster ontrol enter ) #$(eceive #nl& $rinter ) other

%eri%heral devices '

The D/C controls the T+ (Ta%e +rive ) ++ (+is! +rive )'

> CONT2O. N,T :-

The control unit consists of two su*units 8-

A' T&e CC$CENT2A. CONT2O. '1' MM$MA,N MEMO2Y'

A' CC$CENT2A. CONT2O.' :-

t has six "a.or functions 8-

? - E;e%utes 0rogra)s - The contains logic circuits that execute ste%- *&-ste% instructions to control

the o%eration of the , %rocessor'

? - E;e%utes 0rogra) re@uests - res%onds to reuests fro" the S, andfro" "aintenance %ersonnel'

? - 0ro%ess ad)iistrative data - co"%iles re%ort infor"ation and %rintsre%orts %eriodicall&'

? - Moitors sste) oeratio - "aintains a log of eui%"ent status anda list of ##S(out-of-service) eui%"ent'



? - dates Duli%ates C - co""unicates with du%licate stand*& > to!ee% its "/" u%-to-date'

? - Maages data tras6er - ontrols "/" transfer *etween its own "/"its hard dis! the

"icro%rocessor that serve the %eri%heral units in the #$'

1' MM$MA,N MEMO2Y' :-

The ,, stores %rogra" instructions and data' The ,, stores theinstructions and other data needed *& the %rocessor to %rocess calls collect ad"inistrative infor"ationand %erfor" s&ste" "aintenance'

AM 0E2,0HE2A. COM0ONENT /NCT,ONS :-

D,S4 /,.E CONT2O..E2 :-

The +F is res%onsi*le for interfacing with the SS(S"all o"%uterS&ste" nterface) %eri%heral devices such as the dis! and ta%e drives'

SCS, D,S4 D2,8E :-

The functions of the SS(S,99 #,$>TE SHSTE,:TEFE) dis! drive are as follows 8-

• Stores co%ies of software used in the 5 ESS-2000 Switch --if data in the,, is lost it is restored fro" the dis! co%&'

• Stores hardware configuration data I infor"ation on the dis! defines theconfiguration of hardware and line and trun! ter"ination'

• Stores *illing data I dis! has a te"%orar& area for *illing data' The data

is stored until it is reuested *& the host collector or du"%ed to ta%e'

TA0E D2,8E :-

The ta%e drive is a *ac!u% for infor"ation stored on dis!' The ta%e drive"a& *e either a conventional



co"%uter nine trac! ta%e drive or a +T( +1T9 >+# T$E)'+ata can *e transferred fro" ta%e to dis! or fro" dis! to ta%e' Billing data for the evenue ccountingoffice is also stored on ta%e'

,N0T3OT0T 02OCESSO2 :-

The #$ is the interface for other %eri%heral devices used *& the switchsuch as "aintenance nterfaces (, and #$) datalin!s and alar" signaling'

MASTE2 CONT2O. CENTE2' :-

The , "aintains u%-to-date records on s&ste" o%erations and !nowsthe status of all hardware units throughout the exchange' This infor"ation is availa*le to "aintenanceinterface called the , is the "ain local wor! station for "aintenance %ersonnel' t uses a full- colorvideo dis%la& ter"inal as a window to the s&ste"' B& entering %o!e co""ands selected fro""enus on the ter"inal screen or "an

"achine language co""ands selected fro" the 5 ESS-2000 Switch

o""ands nd e%orts ,anual "aintenance %ersonnel can diagnose eui%"ent re"ove eui%"entfro" service restores eui%"ent

to service test lines and trun!s and "odif& the data*ase and servicefeatures for custo"ers' The #$

(eceive-#nl&-$rinter) %rovides a %rinted co%& or re%orts fro" the,'

The %ri"ar& functions of the , are to %rovide the following 8-

) Cisual dis%la&s of s&ste" status and alar" infor"ation'2) The "eans to control test and reconfigure the s&ste"'=) The "eans to "anuall& recover the s&ste"';) ccess to exchange data '

CA.. 02OCESS,NG :-



O8E28,E+ :-

t %rovides a funda"ental descri%tion of line-to-line and trun!-to-trun!calls in a 5 ESS-2000 Switch '

CA.. 02OCESS,NG STAGES :-

There are five functional ste%s of call %rocessing including the locationof the originating and ter"inating eui%"ent' These ste%s are 8

? - Origiatio :- t *egins when the su*scri*ers line goes off-hoo! or

when an inco"ing trun! issei?ed'

#rigination receives the inco"ing digits selects the digit anal&sista*les and deter"ines the screening infor"ation for this call'

? - Digit Aalsis :- t inter%rets the digits that it receives for" originationselects a destination for each call and %asses the dialed digits to routing'

? - 2outig3S%reeig :- outing uses the destination infor"ation fro"digit anal&sis and screening

infor"ation fro" origination to select the ter"inating trun! grou% orline' The t&%e of charges associated with this call is deter"ined and sent to charging'

? - C&argig :- t uses the charging infor"ation fro" routing to ex%andthe charging data into a

for"at usea*le *& the all ccounting %rocess' There are varioust&%es of call accounting features fro" *asic , records to Fee alculation'

? - Ter)iatio :- The last ste% in call %rocessing is ter"ination'Ter"ination %rocess are different for calls destined for lines and calls destined for trun!s'



Tru! Ter)iatio - an idle trun! "e"*er of the trun! grou% isselected *ased on a %re-deter"ined %attern' fter selection digits are out%ulsed to the distant office'

.ie Ter)iatio - the line identified in routing is chec!ed todeter"ine if the line has an& s%ecial features' inging is a%%lied to the line if a%%lica*le or the s%ecialfeature is activated'

CA.. 02OCESS,NG :-

The "ost i"%ortant function of a 5ESS-2000 Switch is to %rocess

su*scri*er calls ' Su*scri*erJs calls can *e classified as line-to-line line-to-trun! trun!-to-line ortrun!-to-trun! ' line-to-line call is a call that starts on a line served *& a 5ESS-2000Switch ter"inates to another line served *& the sa"e switch ' The S,s involved in the call will %erfor" al"ost65 7 of the call %rocessing

functions '

+uring a line-to-line call the originating S, detects when a

su*scri*erJ s tele%hone receiver has *een %ic!ed u% ' The S, %rovides dial tone then re"oves dial tone

when the first digit is dialed ' t then collects anal&ses the dialled digits ' :ext the S, sends areuest to the , for a call %ath ' Theter"inating S, locates the su*scri*er line for the line-to-line call

%rovides ringing ' 1AS,C CA.. TY0ES

Origiatio Ter)iatio

9ine 9ine

9ine Trun! Trun! 9ine

Trun! Trun!



3hen the , has *een selected an availa*le %ath it alters the ,to set u% a lin! *etween the

S,s'

The , %rovided call %aths *etween S,s carries all internals&ste" co""unications'

The functions of the S,, , in a trun!-to-trun! call are *asicall& the sa"e as the line-to -line descri*ed a*ove exce%ts that the originating S, detects a trun!sei?ure rather than a su*scri*er %ic!ing u% the receiver ' lso the ter"inating locates anavaila*le trun! instead of a line'

f a call involves *oth a line a trun! (line-to-trun! trun!-to-line ) the scenarios a*ove "a& differ slightl& ' lso the scenarios "a& differ de%ending on thea%%lications su%%orted *& &our exchange '

9ine-To-9ine calls can *e of two t&%es 8-

"' ,NT2A-SM - where *oth su*scri*er lines (originated ter"inated ) are connected to sa)e S, '

This doesnJt reuire use of , '

(' ,NTE2-SM - where *oth su*scri*er lines are connected todi66eret S,s ' This reuires use of

, '

5ESS-(BBB S+,TCH A00.,CAT,ONS :-

O8E28,E+ :-

The 5 ESS-2000 Switch was designed with a flexi*le "odulara%%roach with regard to *oth software

and hardware allowing for digital services ca%a*ilities that su%%ort"an& a%%lications' urrent a%%lications su%%orted *& the s&ste" are follows 8



) 9ocal Exchange 2) Toll Exchange =) 1atewa& Exchange ;) #S$S(#%erator Service $osition S&ste") 5) S+:(ntegrated Services +igital :etwor!) <) ST$(Signalling Transfer $oint) ) SS$(Services Switching $oint or ction ontrol $oint) K) ,S(,o*ile Switching enter or 3ireless)

"' .OCA. EXCHANGE :-

9ocal su*scri*erJs gain access to the local exchange through lines 'The exchanges switches a call fro" an internal su*scri*er to another su*scri*er directl& or through a

trun! c!t' to a su*scri*er in another exchange ' trun! c!t' ( or trun! ) connects a local exchangeto another local exchange or

toll exchange ' local exchange has a high 7 of lines a s"all %ercentage of trun!s '

(' TO.. EXCHANGE :-

toll exchange ( or trun! tande" exchange ) connects a localexchange to another local exchange or

to a gatewa& exchange ' toll exchange has a high %ercentage oftrun!s a low %ercentage of lines if an&'

*' GATE+AY EXCHANGE :-

There is one international networ! consisting of interconnectedgatewa& exchanges ' Each countr& (

B ) in this networ! has its own gatewa& exchange an internationaltoll exchange '

nternational calls enter leave the countr& fro" this gatewa&exchange '

=' O0E2ATO2 SE28,CE 0OS,T,ON SYSTEM :-



The 5 ESS-2000 Switch offers auto"atic o%erator services via the#S$S(#%erator Service $osition

S&ste")' #S$S a%%lications are director& inuir& and Trafficssistance' +irector& nuir& allows

o%erators to su%%l& director& nu"*ers to calling su*scri*ers' Trafficssistance allows o%erators to

co"%lete calls and res%ond to inuires for su*scri*ers' The #S$S usesa s%ecial S, called a

$S,($osition switching ,odule)'

5' ,NTEG2ATED SE28,CES D,G,TA. NET+O24 :-

nother t&%e of 5 ESS-2000 Switch a%%lications is the S+: (ntegrated

Services +igital :etwor! )'S+: offers new voice data services allows features such as#S$S' S+: also allows voice data

signalling infor"ation to travel over the sa"e digital su*scri*er line 't lets all three co"%onents use

the sa"e trans"ission %ath si"ultaneousl& '

Two %eo%le with S+: can "a!e %hone calls use their co"%uterter"inals to access one or "ore co"%uters at the sa"e ti"e' S+: service is full& co"%ati*le with $#TS

service' S+: service reuiress%ecific S+: hardware software in the S, '

' S,GNA.,NG T2ANS/E2 0O,NT :-

The ST$ ( Signalling Transfer $oint ) is an exchange a%%lication thatsends signalling "essages on their

wa& to the %ro%er destination over a different %ath than the associatedvoice c!t' ST$s are associated

with the S (o""on hannel Signalling ) ' This a%%lication

allows for "ore efficient use oftrun! circuits'

' SE28,CE S+,TCH,NG 0O,NT :-

The SS$ (Service Switching $oint ) also called $ ( ction ontrol$oint ) is a 5ESS-2000 Switch



a%%lication that is %art of an : (ntelligent :etwor! ) configuration ': technolog& allows the

introduction of advanced services %ri"aril& through software u%dateswith "ini"al networ!

rearrange"ents "ini"al service disru%tion ' The SS$ is a*le torecognise an inco"ing : call

%rocess it or reuest call handling instructions *& use of a re"otedata*ase that is accessed *& "an&

switches in the : '

' MO1,.E S+,TCH,NG CENTE2 :-

The ,S ( ,o*ile Switching enter ) %erfor"s the switching functionsfor wireless s&ste"s ' This5ESS-2000 Switch a%%lication "onitors su*scri*er "o*ilit& "anages

resources co""unicates withother networ!s %erfor"s call routing control functions ' The ,S

configuration includes an ,, S,s 31S, (3ireless 1lo*al Switching ,odule ) at least one

3S, ( 3ireless Switching,odule ) %ossi*l& a 3S, ( 3ireless e"ote Switching ,odule )

or "ulti"odule '

MA,NTENANCE TOO.S :-

O8E28,E+ :-

The , ( ,STE #:T#9 E:TE ) >ST#,E+#>,E:TT#: T93S (T>: :+ 9:E 3#STT#:)

function /C ( EE:T 4:1E :+ CEFH ) function are allessential tools for 5ESS- 2000 Switch "aintenance'

MCC $MASTE2 CONT2O. CENTE2 ' :-

The , is the %ri"ar& co""unication lin! *etween "aintenance %ersonnel the 5ESS-2000



Switch for %erfor"ing the "aintenance functions ' n s"aller exchanges itis %ossi*le to have onl& the , ter"inal ' 9arger exchanges will need"ore ter"inals %rinters '

• T.+S $T2N4 AND .,NE +O24STAT,ON ' :-

The function of the T93S is to test the lines trun!s in an exchange'This function "a& *e invo!ed fro" ter"inals located within the exchange(, ) or fro" re"ote "aintenance facilities '

The ter" T.+S can *e used to reference the T93S function (software )or the ter"inal used to access the T93S function (hardware ) ' ter"inalis defined for use as a T.+S in the switchJs E+ data*ase'

T.+S /u%tio 8-

The T93S function is used to 8-

L e"ove restore service to su*scri*er lines trun!s for testing '

L Test su*scri*er lines '

L nitiate o%erational trans"ission tests on trun!s '

-- #%erational tests chec! the a*ilit& of a trun! to co"%lete a call'

-- Trans"ission tests "easure the ualit& of signals *eing reserved *& atrun! '

1E.T.,NE C,2C,T :-

So"eti"es tests are %erfor"ed fro" locations other than the ,' Forinstance during installation difficult fault conditions "ight occur in theS,(Switching ,odule) that can *e located a distance fro" the ,' This

"a& cause so"e inconvenience for "aintenance %ersonnel since the& "ustwal! *ac! and forth *etween the S, and the ,' To avoid that the ESS-2000 Switch fra"es(ca*inets) are eui%%ed with connectors to allow the"aintenance %ersonnel to connect %orta*le /# devices such as a TTH or ater"inal with !e&*oard near the S,' This feature is called the beltlie%ir%uit'



Beltline .ac!s (connectors) are "ulti%lied at o%tional fra"e locations aroundthe exchange "a!ing the circuit accessi*le fro" several %oints' The& are"ounted on a .ac! stri% located *etween the fuse %anels at the to% of theeui%"ent fra"es' lthough the *eltline .ac!s can *e "ulti%lied to each S,a "axi"u" of two *eltline circuits "a& *e used at the sa"e ti"e' The& arereferred to as Beltline Beltline B' The *eltline .ac!s are wired to the

%eri%heral controllers in the #$(n%ut/#ut%ut $rocessor )>nit'

2ECENT CHANGE AND 8E2,/Y :-

The /C(ecent hange and Cerif&) function ena*les &ou to view andalter the 5 ESS-2000 Switch data*ases and is accessed fro" the,(,aster ontrol entre) #,(#%eration ,aintenance enter)ST93S(Su%%le"entar& Trun! and 9ine 3or!stations) or fro" o%tionall&

eui%%ed /C ter"inals' The , and the #, have access to all /Cfunctions' ndividual ter"inals however "a& *e restricted to s%ecificfunctions'

/C %rovides the ca%a*ilit& to view and alter the data*ases in the 5 ESS-2000 Switch'

3C function has the following two "odes 8-

• (ecent hange) "ode %rovides a wa& of accessing and changing the

s&ste" data*ases to reflect changes in custo"er services or s&ste"ca%a*ilities'

• C(Cerif&) "ode %rovides the a*ilit& to view *ut not change data*asecontents' This allows one to verif& that the correct changes were "ade'

OCB-283 EXCHANGE SYSTEMS

) Salient Features 8

• #B stands for O2GAN CONT2O. 1HE2S,ON• +igital switching s&ste" develo%ed *& ,/s T 9TE9 of France'• +igital switching s&ste" with single MTN stage'• #, S/: are du%licated'• Cariet& of services %rovided are



i) Basic Tele%hon&ii) S+:iii) ,o*ileiv) Cideo text v) others

• t su%%orts different t&%es of signalling s&ste"s 8i) +ecadicii) ,Fiii) Siv) TT :o'-

• ,ax no' of .unctions "a& *e <0000• #nl& =5 t&%es of ards ( excluding S: )•

S%ace reuire"ent is ver& s"all• Environ"ental reuire"ent is not ver& stringent• Traffic handing ca%acit& is K00000 B4• uto"atic fault recover& feature re"ote "onitoring• #%erating s&ste" used is T#S (eal Ti"e #%erating S&ste" )• 9anguage used is 499

2 ) ,O# >:TS #F #B SHSTE, 82' ) S: (S>BSBE #::ET#: >:T ) 8

t is S:9 for local su*scri*erJs it is S:+ for re"ote su*scri*erJs ' S: *asicall& consists of Basic ac! = Extensions ac!s' a%acit& ofS: is 5000 "ax' Su*scri*erJs "a& *e nalogue +igital' ) TBS - For #rdinar& su*' -< su*' %er card 'B ) TBE - For ho"e "etering - < su*' %er card ' ) TB:- For S+: su*scri*erJs - consu"es < %orts

2'2 ) T>: :+ O>:T#: #::ET#: >:T (S,T ) 8t is the interface *etween the switching networ! .unctions fro" otherexchanges ( or re"ote n su*-connection unit )

2'=) S3T4:1 ,T@ (S,@ ) 8t is a single stage M T N ' t is "ade u% of 4ost Switching ,atrix *ranchselection "%lification Function S,@ is du%licated'

) >@9H EP>$,E:TS #:T#9 STT#: ( S, ) 8



t contains ET $>$EET consists of fre' eceiver/1enerator conference calls TS ' Tone 1enerators - $>$E So"e +#ES functions ofTT :o' '

2'5 ) ontrol >nits(S,) 8 There are six control units as under 8

a) ,ultiregister(,) - for esta*lishing and releasing of calls' *) Transistor(T) - for storing Exchange data*ase'c) harging >nit(Tx) -for carr&ing out charging .o*s'd) ,ar!er(,P) - %erfor"s connection disconnection of su*scri*er'e) S- ontroller($)- for carr&ing out routing traffic "anage"ent

functions'f) ,atrix S&ste" 4andler(1@) - for "onitoring connection in S/:

2'<

) #%eration ,aintenance >nit(S,,) 8

t is #, for su%ervising functions of different units and for ta!ing suita*leactions at the event of faults' t uses two identical "icro%rocessors,otorola-<K0=0' There are two "agnetic dis!s each of ca%acit& '21B forvarious storage' #ne strea"er drive of 525,B is %rovided for initialisationand *ac!u% etc' There are two "agnetic ta%e drives for transferring chargingdata for *illing etc su*seuentl&' S,, is du%licated '

#, (#$ET#: :+ ,:TE::E E:TE ) 8

t is a general %ur%ose co"%uter called ,T-225 su%%lied *& ,/S-Tlcatel France through ,/s'T 9td' #ne co"%lete s&ste" consists of $> unit ; ,agnetic Ta%e >nit (,T>s ) 4ard-dis! drive' s%ares&ste" consisting of $> unit ,agnetic Ta%e >nit 4ard-dis! driveused as a stand *& s&ste" '

EP>E,E:T #F #, 8The nor"al call connection in E-0B exchange is inde%endent of #, 'The

su*scri*ers will not *e affected if the #, fails' This #, s&ste" isreuired *& the "tce staff for feeding/ retrieving infor"ation to / fro" E-0B exchange' The following tas!s will not *e %ossi*le to carr& out if the#, fails 8-

i) nterrogation of su*' data li!e "eter reading status of %hone-%lus facilit&etc'



ii) ,odification of su*' data li!e creation/ addition /su%%ression of new su*'line *arring/ restoring of ST+ service %roviding/ deleting %hone - %lusfacilities etc

iii) nterrogation of Exchange data li!e status of all the units of exchange status of $, lin!s c!t' grou% status traffic data etc

iv) ,onitoring of exchange data su*-data li!e %eriodic traffic re%ort .unction re%ort o*servation data %rint out of fault "essages generated *&various units re%air of various diagnostics testing of su*' lines testing of

.unction etc'v) etrieval #f Calua*le +ata 8- $re%aration of *i"onthl& "eter- reading

ta%e (T@9 Ta%e ) saving of "e"or& data of control units (,,S>Ta%e ) %re%aration of s&ste" ta%e'

BASIC CONSTITU ENTS OF THE OMC SYSTEM :

The %ictorial view of ,itra-225 #, co"%uter is shown in the fig' Theco"%lete co"%uter s&ste" is covered in ; ca*inets as shown *elow 8- ) $> >:T 8- t consists of the following $Bs ($rinted !t' Board ) $> $ower Su%%l& 90 eal Ti"e loc! T , ou%ler E$-56 ,agnetic Ta%e ou%ler #$-50 ,agnetic Ta%e ou%ler ,$-50

+is! ou%ler :ESSE- da%tor +is! ou%ler :ESSE- #%erator

3atch -dog Ti"er E$-<= s&nchrous ou%ler 9$-55

The :o' of 9$-55 $Bs "a& var& fro" to ; de%ending u%on no' ofter"inals connected with this s&ste"' 9$-55 can cater K %eri%herals for"ore than =2 %eri%herals extension shelf is to *e used' Eight - External nterru%t E$ -5; ,E ou%ler $-5 $> T:-5 25< !* ,ain ,e"or& ,E-0=

( ' MAGNET,C TA0E N,T $MT ' O2 1M $1AND MAGNE,C ':-

The ,T>s are used as auxiliar& storage device 'There are total 5 ,agneticta%e units out of which 2 ,T>s are %rovided with For"atter $B designated as B,-0 (,tce) rest of the ; i'e' B,-0 B,- B,-2 B,-= are used for nor"al s&ste" wor!ing ' The ,agnetic Ta%e >nit B,-0



is of "ore i"%ortance *ecause it controls rest of the = drives will not wor! 'n such event we have use B,-0 ( ,tce ) in %lace of B,-0 ( service )'The "agnetic Ta%e >nits are used for the following functions 8-

• Storing +etail - Billing ,essages ( 1T+T Ta%e )• Storing fault ano"al& "essages ( #FF Ta%e )• $re%aring su*scri*erJs -"eter - reading Ta%e ( T@9 Ta%e )• $re%aring control units "/" data Ta%e (,,SC Ta%e )• $re%aring s&ste" Ta%e ( S&ste" Ta%e )

C#>S TH$ES #F ,T>s >SE+ : T4E SHSTE, 8-3ith the fast technolog& u%gradation ever&ti"e we find new t&%e/ "odelof "agnetic ta%e unit ' $resentl& = t&%es of ,T>s are availa*le at different#, sites in ndia 8-)

$ETE t&%e - ,ade in >S2) ++F t&%e - ,ade in France=) ++F- $ETE t&%e -,ade in France

To save the detail Billing ,essages when the #, fails "ag' Ta%eunit (B,-0) is %rovided in +SF rac! of each E-0B exchange ' The ++Ftu%e ++F- $ETE t&%e "icro%rocessor *ased "ag' ta%e units used in#, as B,-0 are full& co"%ati*le with the ++F or ++F-$ETE T&%eB,-0 used in +SF rac! '

D,S4 N,T D-B :-

This is also used as auxiliar& "/" for ,T-225 o0"%uter ' t %la&s avitial role in "an -"/c dialogue ' The s&ste" a%%lication data of differentE-0B exdchanges connected with the #, are stored in thedis! drive ' The data storage ca%acit& is K0 "ega *&te' #ut of the 2 dis!driver is connected to service $> the other is !e%t as stand*& dis!'

n earlier su%%lies of ,T-225 the dis! %ac!s inside the #+-K0 dis!drive re"ova*le dis! %ac! and fixed dis! %ac! and fixed dis! %ac!' ll the

useful data are stored an fixed dis! %ac!'

Two Filters 8

#ne %refilter and one a*solute filters are used in >+-K0 dis! drive to %rovide a dust -free enviro"ent in dis! area' $eriodic clearing of %re-filter



and change of a*solute filter is a "ust for fault free o%eration of the >+-K0dis! drive'

$ossi*ilt& of 4ead crash due to +ust 8

The diagra" *elow de%icts how the head crash can occur in dis! due to %resence of various t&%es of dust %articles on dis! surface'

B& wa& of indication we are showing *elow the co"%aritive si?es of so"e %ollutants and the height of the head'

SECE TE,:9 ,E 8

The service ter"inal ,E is used as co"%uter console !e&*oard for direct

dialogue with co"%uter' #, s&ste" is initialised through this ter"inal'There are two ,E %rovided one for service unit other for stand*&s&ste"'

#ther $eri%herals 8

• Tele T&%e 3riter(TTH)• Cideo +is%la& >nit(C+>)• $rinter

These %eri%herals are the "edia through which "an-"achine dialogue ta!es %lace' The no' of TTH/C+>/ de%ends on :o' of exchanges connectedsi?e of each exchange no' of fault control%osition in test roo"s' s"entioned earlier K ter"inals can *e connected to one 9$-55 $B in $>unit' For "ore than ;9$-55 $Bs(i'e for connecting "ore than =2 ter"inals)extension shelf has to *e installed to acco""odate "ore 9$-55 $Bs' TheseTTH/C+>/ are located in ex%loitation roo" or test roo" ' For shorterdistances(a*out 00ft) these %eri%herals can *e directl& connected to #,'>se of %eri%herals at distant %laces reuire ,#+E,' These ,#+E,S areinstalled in B,# rac! in the #, roo"' The TTHs wor! at =00 Bauds

s%eed while C+> wor! at 200 Baud s%eed'

34ET4E E1>9 ,:TE::E #F ,T- 225 #,SHSTE, EP>E+ 8

s "ost of the %eri%heral devices are of electro"echanical t&%e hence %eriodic chec!ing for their wear and tear and cleaning is also reuired' The



,tce schedule for the #, %eri%herals to *e carried out *& exchange,tce staff' These ,tce tas!s should *e %erfor"ed ti"el& to ensure fault-free o%eration and long life of %eri%herals' The details of tas!s carrried out

*& , tea" during "onthl& %eriodic ,tce '

Each #, site has *een su%%lied with one +E9SEH T##9T Test Ta%escalled SE,S ta%e SE3 ta%e ,TT ta%e and s%ares and consu"era*le'These ite"s are used for testing the $> $Bs ,T>S +is!s and other

%eri%herals'

$#:TS T# BE 4EE+ +>:1 :S$ET#: #F ,T-225#, SHSTE, 8

$#:TS #,,E:TS

) 3hether #, S&ste" is wor!ingnor"al without an& lin! failure %ro*le" Q

) There should not *e freuent lin!failure %ro*le"'

2 ) re there freuent T$"essages or +S ccess Error"essages on ,E Q

2 ) For a relia*le s&ste" no such"essages should co"e '

= ) 4ow "an& units of #, aredown Q

= ) 3henever an& ,T>-0 /or>$-K0 dis! is fault& i""ediateaction should *e ta!en to get itre%aired '

; ) 4ow "an& #, $Bs of $>rac! are %ending fault& Q

; ) t should *e re%orted to , '

5 ) 3hether exchange "tce staff are %ro%erl& carr&ing out "tce activitiesas %er +#T guidelines Q

5 ) These should *e carried out as %rescri*ed *& +#T '

< ) 3hether < "onthl& %eriodic "tceis *eing carried out *& , tea" Q*solute filter of >+-K0 dis! drivenhas *een changed or not '

< ) :or"all& after ever& < "onths the a*solute filters of *oth >+ -K0dis! drives has to *e re%laced *& newone to avoid head-crash dis!failure '

) 3hether all #, activities are *eing %ro%erl& recorded in M#,"tce log *oo!N'

) ll activities should *e recordedin %ro%er for"at as suggested *&+#T '

K ) 3hether sufficient no' of s%are"ag' ta%es are availa*le Q

K ) "in' =< "ag' ta%es of goodualit& should alwa&s *e availa*le(for #, R Exchange )'



6 ) re the "ag' ta%es %ro%erl&stored in a cu% *oard records oftheir use "ainted in register Q

6 ),ag' ta%es should *e stac!ed oneover others instead the& should *e

%ro%erl& arranged in well %rotectedcu% *oard ' record should *e"aintained to identif& "uch useedta%es for re%lace"ent '

0 ) 3hether all the staff on dut& area*le to Mnitialise the #,N o%ening of "ag' ta%e for 1T+T /#$F Q

0 ) ll "tce staff of OT# level a*ove should at least !now #,initiali?ation "ag' ta%e o%eration '

) 4ow "an& %eri%herals TTH/ /C+> are fault&Q

) Fault should *e locali?ed *&exch'-staff re%orted to ,'

2 ) 3hether all the tools availa*lein +E9SEH T##9 T Q

2 ) f an& tools are "issing/ lost thesa"e should *e arranged

i""ediatel&'= ) 3hether ,,S> ta%e is *eing %re%ared ever& wee! Q

= ) The ,,S> ta%e should *e %re%ared atleast once in a wee! foreach exch' onnected to #, should *e tested for loading of datain control unit fro" +SF once in a"onth'

; ) 3hether %ro%er environ"entalconditions are "aintained in #,roo" Q

; ) elative hu"idit& te"%' dustfree environ"ent should *e"aintained for %ro%er fault free

o%eration of #, %eri%herals'

:1E,E:T #F $SS3#+ :+ 1#>$:1 #F #,,:+S 8

) There are nearl& =20 co""ands availa*le in E-0B s&ste" for %erfor"ing various functions ' These co""ands are grou%ed %ut into< different classes' n& class of co""and can *e %ut in %assword for

%rotection ' There is a co"%lete flexi*ilit& regarding arrange"ent ofco""ands in different classes in E-0B exchanges' 3hatever has *een

arranged *& the installer either the so"e is *eing followed or so"e +Esare arranging co""ands as %er their convenience ' t is also noticed thatin so"e exchanges so"e i"%ortant co""ands are not guarded *&

%assword't has further *een noticed that it is %ossi*le to %revent incre"enting ofsu*s' "eter reading during ST+ call *& entering certain co""ands are

%ossi*le "isuse of this deficienc& in this s&ste" cannot *e avoided with the



intention of "al-%ractice' This deficienc& in the s&ste" has alread& *een *rought to the notice of TE for wor!ing out suita*le %reventive solution'

2 ) Till the ti"e TE is a*le to *ring out suita*le solutions to strea"line thearrange"ent of %assword in E-0B exchange a co""ittee was constituted *&,T:9 Bo"*a& , Bo"*a&'

EWSD EXCHANGE SYSTEM

,trodu%tio :-



fter &ears of *eing treated as a luxur& teleco""unications has co"e intoits own in the eighth $lan' The +e%art"ent of Teleco""unications hasannounced a"*itious %lans for the addition of '5 "illion lines to theexisting 5'K "illion *& the end of the Kth %lan(662-6) as co"%ared to onl&='2 "illion in 6K2-62'

To *ridge the ga% *etween the su%%l& and de"and +oT invited a tender for200000 lines of switching eui%"ent on u%ee %a&"ent' n the industrial

%olic& of Oul& 66 Teleco"' eui%"ent was delicenesed and through o%ento foreign invest"ents' onseuentl& six new technologies were %lanned to

*e validated' These foreign su%%liers set u% their validation exchanges eachof 0000 lines ca%acit&(including two S>s of 2 each) at different

%laces e'g' E3S+ of Sie"ens(1er"an&) at alcutta @E-0 ofEricsson(Sweden) at "adras Fetex-50 of fu.itsu(Oa%an) at Bo"*a& #B-

2K= of 9TE9(France) at +elhi etc'

Three new +igital Switching S&ste"s i'e' E3S+@E-0 Fetex-50which got validated first were inducted in the ndian Teleco"' :etwor! three la!h lines were i"%orted fro" these three su%%liers' n addition ='5la!hs lines were also i"%orted on lease *asis fro" these su%%liers'Su*seuentl& four "ore switches i'e' #B-2K= of 9TE9(France) 5ESS of TT(>S) S&ste"-@ of 1$T(>) and :E-<E of

:E(Oa%an) also got validated'

E3S+ is one of the two technologies selected for T@ and is also thetechnolog& for ntelligent :etwor! and ,o*ile o""unication'

SYSTEM /EAT2ES :-

E3S+ +igital Switching S&ste" has *een designed and "anufactured anddesigned and "anufactured *& ,/s Sie"ens 1er"an&' The na"e isa**reviated for" of 1er"an euivalent of Electronic Switching S&ste"+igital E3S+ switch can su%%ort "axi"u" 250000 su*scri*ers of <0000inco"ing outgoing or *oth wa& trun!s when wor!ing as a %ure tande"

exchange' t can carr& 25200 Erlang traffic and can withstand '; "illionB4' t can wor! as local cu" transit exchange and has S :o'' S+:and : ca%a*ilities '

SYSTEM A2CH,TECT2E :-



The "ain hardware units of an E3S+ Switch are as under 8-

$"' Digital .ie it $D.' :- functional unit on which su*scri*er linesare ter"inated'

$( ' .ie3Tru! Grou $.TG' :- +igital Trun!s are connected to 9T1s'

The access function deter"ined *& the networ! environ"ent are handled *&+9>s and 9T1s'

$*' Swit%&ig Networ! $SN' :- ll the 9T1s are connected to the S:which inter connects the line and trun!s connected to the exchange inaccordance with the call reuire"ent of the su*scri*ers' : and $ arealso connected to S:'

$=' Co-ordiatio 0ro%essor $C0' :- t is used for s&ste"-widecoordination functions such as routing ?oning etc' 4owever eachsu*s&ste" in E3S+ carr&out %racticall& all the tas!s arising in their areainde%endentl&'

$5' Co))o C&ael Sigallig Networ! Cotrol $CCNC' it :- Thisunit functions as the ,essage Transfer $art(,T$) of S-' The >ser$art(>$) is incor%orated in the res%ective 9T1s'

Bloc! diagra" of E3S+ is given in fig'' t also shows that the "osti"%ortant controls are distri*uted throughout the s&ste"' This distri*utedcontrol reduces the coordination overheads and the necessit& ofco""unication *etween the %rocessors' t results in high d&na"ic

%erfor"ance standard'

For inter-%rocessor co""unications <; !*%s se"i%er"anent connectionsare set through S:' This avoids the necessit& for a se%arate inter%rocessornetwor!'

S1SC2,1E2 3 ADM,N,ST2AT,ON /AC,.,T,ES ,N E+SD :-

' 2aid %all set u :- - **reviated +ialing - 4otline ""ediate

- 4otline with Ti"e #ut2' Call 2estri%tio Servi%es :-



- #/1 estrictions - d"inistration ontrolled

- Su*s controlled - / Barring=' Abset Subs%riber Servi%es

- ""ediate diversion- +iversion on no re%l&

- to o%erator - to a nu"*er

- to announce"ent;' Call Co)letio servi%es - +iversion on *us&

- all 3aiting - all %riorit&(originating ter"inating)

5' Multiart servi%es - onference call - Tele-"eeting<' Alar) %all boo!ig :- - asual

- egular (nu"*er of consecutive da&s)' Servi%es to 01X - +irect dialing in (for different $B@ ca%acities)

- 9ine huntingK' Mis%ellaeous Servi%es

- ,alicious call identification - ll calls - S%ecial su*scri*er signal6' Call %&arge servi%es :-- Se%arate counters for 9ocal all charges ST+/S+ calls charges

:u"*er of calls Serviceactivation charges and Service usage charges

- Trans"ission of "eter %ulses- $reventive "eter o*servation (ad.usta*le threshold)

SYSTEM DATA

all -handling ca%acit& :o' of Su*scri*er lines - "ax' 250000

:o' of Trun!s - "ax' <0000



Switcha*le traffic - "ax' 25200 E

Su%%l& Coltage -;K C no"inal direct voltage

loc! accurac& ,axi"u" relative freuenc&deviation 8

%lesiochoronous 0 ex% -6 s&nchronous 0 ex%' -

Signaling s&ste"s ll conventional signaling s&ste"se'g TT 2 :o'5 :o'

nalog su*scri*er line trun!

accesses

Carious loo% and shunt resistance

%ossi*le'$ush-*utton dialing ,ultifreuenc&'Signaling to TTeco""endation '2=otar& dialing 8 5 to 22 %ulse/s

S+: accesses Basic access 8 <0!*%s(2BR+Rs&nc') B<; !*%s +<!*%s

$ri"ar& rate access 8 20;K!*%s(=0BR+Rs&nc')

+igital trun! accesses 20;K !*%s

Traffic routing $er destination "ax' high-usageroutes and one final route Seuentialor rando" selection of idle trun! of atrun! grou%

:u"*er of trun! grou%s %erexchange 8 ,ax' 000 inco"ing and ,ax' 000 outgoing and ,ax' 000 *othwa&

all charge registration $eriodic %ulse "etering



, 8 uto"atic ,essageccounting or

+etailed Billing(,9,)STT (nter d"inistrationevenue accountingand Statistics)

,ax'2 ?ones,ax'< tariffs %er ?oneTariff switchover %ossi*le in5-"inute ti"ing intervalsTrans"ission of co""unication datato co"%uter center (out%ut on ta%e

also %ossi*le)S%ace reuire"ents Exa"l%e 8 Exchange for 2;000 linesunits a%%ro'00 "eter suare'

Environ"ental conditions "*ient te"%erature 8 5 degreecentigrade to ;0

degreecentigradeelative hu"idit& 8 07 to K07

Documents

20938555 Switch Basics 5ESS