Lucent Technologies Ds1/Cept1/Isdn Pri Reference Manual

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Applications 
Page 2-4 Public Network Applications in the United States 
2
nDirect inward  d ial (DID) service
nElec tronic  Tand em Network (ETN) servic e 
Eac h of the ab ove ap p lic ations is availab le over DS1 rob bed  bit or DS1 c ommon 
c hannel BOS trunks. They are also availab le over DS1 ISDN PRI trunks if the loc al 
or foreig n exc hange is equip p ed  with an ISDN PRI-c ap ab le switc h, suc h as the 
AT&T 5 ESS
® or the Northern Telec om DMS® 100.
Interexchange Carrier Applications
AT&T, MCI, U.S. Sp rint and  other interexc hang e c arriers (IXCs) in the U.S. offer 
various servic es ac c essib le over d ig ital trunks. This d oc ument d isc usses only the 
AT&T servic es. AT&T offers many d ig ital servic es, b ut only some of these are 
ap prop riate for use with private switc hing  systems. The following  ap p lic ations are 
availab le using DS1 robb ed  b it trunks and  DS1 ISDN PRI trunks in the United  
States throug h AT&T interexc hange switc hes (4ESS
®):
nACCUNET® Switc hed  56 servic e (rob b ed bit trunks only)
nACCUNET® Switc hed  Dig ital servic e (DS1 ISDN PRI trunks only)
nMEGACOM® servic e (rob bed  b it or DS1 ISDN PRI trunks)
nMEGACOM® 800 servic e (rob b ed  b it or DS1 ISDN PRI trunks)
nSoftware Defined Network (SDN) servic e, inc lud ing  Software Defined  Data 
Network (SDDN) servic e (rob b ed  b it or DS1 ISDN PRI trunks)
Note that none of these servic es use DS1 c ommon c hannel trunks. This is 
b ec ause the fac ilities req uired  to ac c ess these servic es are availab le only with 
either rob b ed  bit sig naling  or ISDN PRI sig naling. At p resent, ac c essing  these 
servic es using  DS1 ISDN PRI trunks has the following  ad vantag es:
nThe c all-b y-c all servic e selec tion (CBC) feature is availab le via ISDN PRI 
ac c ess. The CBC feature allows you to use the same trunk g roup  for 
ACCUNET SDS, MEGACOM servic e, MEGACOM 800 servic e, and  SDN 
servic e c alls on a per-c all b asis. In ad d ition, with the G3V2 systems you 
c an further tailor the c all-b y-c all c ap abilities b y ad ministering  a usag e 
alloc ation p lan and  an inc oming  c all hand ling  tab le in the trunk g roup  
administration form.
You d o not have to use CBC. If you wish, you c an p ut the servic es on 
d edic ated  trunk g roup s. For examp le, you c an p ut all ACCUNET Switc hed  
Dig ital Servic es c alls on one of the trunk g roup s and  all MEGACOM c alls 
on a different set of trunk g roup s. Using  c all-b y-c all servic e selec tion with 
the usage alloc ation plan and  the inc oming  c all hand ling  tab le, however, 
c an signific antly inc rease trunk use effic ienc y. 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
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n56 kbps, 64 kbps, 384 kbps, and 1.536 mbps data calls can be made 
t h ro u g h  t h e  4 ESS u s i n g  I SD N  PRI  t r u n ks  w h e re a s d a t a  c a ll s  a re  li m i t e d  t o  
56 kbps maximum using robbed bit trunks. ISDN thus gives the DEFINITY 
user the ability to make mod e 0, mod e 1, mod e 2, mod e 3, and  wid eb and  
d a t a  c a l ls  t h ro u g h  t h e  4 ESS in  a d d it io n  t o  v o i c e  o r  vo ic e -g r a d e  d a t a  c a l ls .  
With rob b ed  b it trunks only voic e/voic e-g rad e d ata and mod e 1 c alls are 
p ossib le. Following  are the c harac teristic s of these mod es: 
— Mod e 0 is 64 kbp s d igital d ata with no p rotoc ol p ac kaging  of any 
kind .
— Mod e 1 is 56 kbp s d igital d ata that uses the DDS b it format.
— Mod e 2 is 64 kbp s d ata p ac kag ed  in an inverted  HDLC p rotoc ol 
and  limited  to user d ata rates b etween 300 b p s and  19.2 kb p s.
— Mod e 3, when c irc uit switc hed, is 64 kb p s dig ital d ata pac kag ed  in 
LAPD p rotoc ol.
— Wid eb and  d ata is d ig ital d ata with no p rotoc ol p ac kag ing  at rates 
that are multip les of 64 kb p s. For tec hnic al information on 
wid eb and  switc hing in DEFINITY systems, refer to 
AT&T DEFINITY 
Wideband Technical Reference
, issue 1, 555-230-230.
nWith ISDN PRI trunks, you c an route c alls to spec ific  trunk g roup s b ased 
on the voic e or d ata c harac teristic s of the c alls. 
nThe ab ility to p ass information to the end  user is availab le with ISDN PRI. 
For examp le, the name of the c alling  party c an b e sent to be d isp layed  b y 
the far-end .
nThe feature c alled  CPN/BN (formerly c alled SID/ANI) is available with all 
ISDN PRI-b ased  servic es. Calling  Party Numb er (CPN) allows the c alled 
p arty to d isp lay the station numb er of the c alling  p arty. Billing  Numb er 
(BN) allows the c alled  p arty to d isp lay the c alling  p artys billing  numb er. 
Two options, whic h must b e sp ec ified  in the servic e ord er, are availab le 
f ro m  t h e  4 ESS a s  f o l lo w s:
— CPN/BN c an b e d elivered  to the DEFINITY systems on a p er-trunk 
group basis.
— CPN/BN can be delivered on a per-call basis, depending on 
whether the DEFINITY system req uests it. G2.2 systems d o not 
have the c ap ab ility to req uest CPN/BN on a p er c all b asis.
nCall setup  times are faster with ISDN PRI.
nCall hold ing  times (the time a trunk is oc c up ied ) is shorter with ISDN PRI.
nG3V2 systems have a built in way to hand le the ad d ition of new servic e 
offering s. If the AT&T network offers a new servic e, the name and  
numeric al value for this servic e c an b e ad d ed  to the network fac ilities 
ad ministration form and  all other related  sc reens are automatic ally 
up dated  to ac c ommod ate the new feature. This c ap ab ility allows G3V2 
users to avert software up g rad es when ad ding  most new servic es. 
						

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nTones are p rovid ed loc ally on ISDN PRI c alls. For examp le, if the far-end is 
b usy, the c alling  switc h p rovid es b usy tone to the c aller.
Call-by-Call Service Selection Application
The c all-b y-c all servic e selec tion (CBC) feature of ISDN PRI offered  b y the AT&T 
network and  sup p orted by DEFINITY systems allows more effic ient use of trunks 
than is p ossib le with robb ed b it trunks, whic h d o not sup p ort c all-b y-c all servic e 
selec tion. The p rimary reason for the ad d ed  effic ienc y with c all-b y-c all servic e 
selec tion is the fac t that with rob b ed  b it trunks, network servic es, inc lud ing  
MEGACOM, MEGACOM 800, ACCUNET Switc hed  56, and Software Defined  
Network (SDN) servic es, must b e p ut on d ed ic ated  trunk g roup s (MEGACOM, 
MEGACOM 800, and  SDN servic es c an b e p ut on the same trunk g roup  with 
SASS, Shared  Ac c ess for Switc hed  Servic es). CBC, however, allows a trunk to 
c arry a c all of any servic e. Thus, without CBC, a servic e with low usag e still 
inc urs the same fac ility c osts (p ort hard ware and  ac c ess c harg es) as a servic e 
with hig h usag e. Also, the trunks used  for the low-usag e servic e have muc h 
unused  c ap ac ity that c ould  b e used  for c alls of another servic e typ e. DEFINITY 
systems use ISDN PRI trunks with CBC to g ain this effic ienc y. You mig ht also 
want to p ut your on-network and  off-network d ata c apab ilities on CBC trunk 
g roup s. For examp le, if you have an SDN network, you c an use the Software 
Defined  Data Network (SDDN) servic e, whic h is a sub set of SDN, for all your 
on-network d ata and  use ACCUNET Switc hed  Dig ital Servic es for your 
off-network d ata ap p lic ations, and  c omb ine the two on CBC trunk g roup s. In 
ad dition, G3V2 systems have three ad d ed c ap ab ilities that further enhanc e CBC. 
These c ap ab ilities are as follows: 
nUsag e alloc ation p lan (ad ministered  in the trunk g roup  form)
nInc oming  c all hand ling tab le (ad ministered  in the trunk g roup  form)
nPer-servic e trunk measurements within a trunk g roup
Usage Allocation Plan in G3V2 Systems
CBC with the usag e alloc ation p lan imp lemented  g ives the user the ab ility to 
d ynamic ally rec onfig ure the availab le b and wid th used  for network servic es in a 
manner that is transp arent to the network. 
Without the usag e alloc ation p lan, c alls of eac h servic e type are treated  eq ually, 
making  it p ossib le or one typ e of servic e to d ominate a trunk g roup  if many more 
c alls of that servic e typ e are mad e. This may not b e d esirab le, however. For 
examp le, if you have a telemarketing  ap p lic ation making  use of MEGACOM 800 
servic e to take c ustomer ord ers, you d o not want your outgoing MEGACOM 
servic e used  b y your emp loyees for long  d istanc e c alls to b loc k inc oming  
MEGACOM 800 calls during hours in which customers can call. You also, 
however, may want to save money by using CBC in order to avoid the need to 
p urc hase another DS1 b oard  and  p ay extra ac c ess c harg es to p ut your 
MEGACOM 800 servic e on d ed ic ated trunks. The usag e alloc ation p lan solves 
this p rob lem b y allowing  you to set minimum and  maximum usag e of a CBC trunk 
g roup  on a servic e-sp ec ific  b asis.  
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
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The following  list summarizes the c ap ab ilities of the usag e alloc ation p lan:
nYou c an d efine up  to three different usag e alloc ation p lans p er CBC trunk 
group.
nEac h p lan allows you to c ontrol how muc h of a CBC trunk g roup  you have 
d edic ated  to a p artic ular servic e. This is analog ous to p utting  servic es on 
d edic ated  trunks and  having  them overflow to a c ommon p ool of CBC 
trunks. Without the usage alloc ation plan, a CBC trunk g roup  is simp ly a 
p ool of CBC trunks to b e shared  by any servic e on a first c ome first served  
b asis. 
nTransitions from one p lan to another c an b e sc hed uled  to b e mad e up  to 
six times a d ay, seven d ays a week. You c an also fix a sing le sc hed ule.
nBec ause you have total c ontrol of your available b and wid th, you do not 
inc ur the re-arrang ement c osts The AT&T network c harg es for 
rec onfig uring  your servic e/trunk g roup  usag e.
nNote that c alls not c ontaining  a valid  Network Sp ec ific  Servic es (NSF) 
c annot make use of the usag e alloc ation p lan. Direc t inward  d ial (DID) 
c alls, for example, do not have NSFs.
Incoming Call Handling Table in G3V2 Systems
In ad d ition to the usag e alloc ation p lan, G3V2 systems have another 
enhanc ement d esig ned  to take ad vantag e of CBC c alled  the inc oming  c all 
hand ling  table. Like the usag e alloc ation p lan, the inc oming  c all hand ling  tab le is 
ad ministered  in the trunk g roup  ad ministration form. The inc oming  c all hand ling  
tab le allows you to treat ind ivid ual c alls in sp ec ial ways. For examp le, all 
inc oming  MEGACOM 800 c alls to a c ertain extension after b usiness hours c an 
b e routed  to a p artic ular destination b y ad d ing  and /or deleting the delivered  
d ig its and /or spec ifying  nig ht destination treatment. The inc oming  c all hand ling  
tab le is well suited  for use with the Dialed  Numb er Id entific ation Servic e (DNIS) 
feature p rovid ed  b y MEGACOM 800 servic e. With the DNIS feature, the network 
d elivers station dig its to the G3V2 systems allowing  exac t id entific ation of the 
numb er c alled . Another feature of the inc oming  c all hand ling  tab le is CPN/BN 
req uest op tion. Depend ing  on how this option is ad ministered  you c an req uest 
either the c alling  p arty number or the c alling  p artys b illing  numb er (formerly 
c a ll e d  A N I )  t o  b e  d e l iv e re d  f ro m  t h e  4 ESS.
Note that the inc oming  c all hand ling  tab le is not limited  to CBC trunk g roups 
b ec ause ind ivid ual c alls all of the same servic e typ e c an rec eive spec ial 
treatment b ased  only on the rec eived  d ig its. Also note that the dig it mod ific ation 
p erformed  b y the inc oming  c all hand ling  tab le oc c urs b efore any AAR or ARS 
d ig it analysis or mod ific ation.  
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
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Per Service Trunk Measurements
A variety of measurements c an b e taken on c all-b y-c all trunk g roup s on a 
p er-servic e and  p er-memb er b asis. For example, you c an measure the 
p erformanc e of a c all-b y-c all trunk g roup  and  c omp are that to your d esired  
p erformanc e. You c an then use the results of the c omparison to alter the usag e 
alloc ation p lan p arameters to ac hieve the d esired  p erformanc e.
ACCUNET Switched Digital Services and
Switched 56 Service
ACCUNET Switc hed  Dig ital Servic es and  ACCUNET Switc hed  56 servic e are 
measured  d ig ital d ata c ommunic ations servic es that use the 4ESS to switc h c alls 
b etween endp oints sub sc rib ing  to the servic e. The DEFINITY systems c onnec t 
d i re c t ly  t o  t h e  4 ESS vi a  d i g it a l t r u n ks  w i t h o u t  b e i n g  s w it c h e d  t h ro u g h  t h e  L EC  
o ff i c e .  Th is  t y p e  o f  a c c e ss  t o  t h e  4 ESS is  c a ll e d  s p e c i a l  a c c e s s.  Th e  d iff e re n c e  
b etween Switc hed 56 servic e and Switc hed  Dig ital servic es is in the types of 
trunks req uired . ACCUNET Switc hed  56 servic e req uires rob b ed  b it trunks while 
ACCUNET Switc hed  Dig ital Servic es req uires DS1 ISDN PRI trunks. The p rimary 
ap plic ation of these servic es on the DEFINITY systems is to allow 
c ommunic ations between various d ata end p oints on the DEFINITY systems and  
d ata end p oints ac c essib le throug h the AT&T switc hed  d ig ital network. The 
switched digital network is an end-to-end digital network accessed by dialing 
numb ers of the form 700-737-XXXX (to end p oints on ISDN ac c ess) or 
7 0 0 - 5 6 X-XXXX ( t o  e n d p o i n t s  o n  ro b b e d  b i t  a c c e s s ) o ve r t ru n k s c o n n e c t e d  t o  t h e  
4ESS. With Switc hed  56 (S56) servic e, only 56 kb p s or voic e c alls are p ossib le 
b ec ause rob b ed  b it trunks are used . Bec ause Switc hed  Digital Servic es (SDS) 
uses ISDN PRI trunks, however, 64 kb p s c alls and  multip les of 64 kb p s c alls are 
possible, meaning voice, mode 0, mode 1, mode 2, mode 3, and wideband calls 
are possible. At present, the only wideband rates supported by the 4ESS
® are 
384 (6X64) kb p s, c alled  the H0 rate, and  1536 (24X64) kb ps, the H11 rate. When 
you ord er SDS or S56, the AT&T servic e p rovid ers assig n a 700 number to the 
end p oints. Thus, you would typ ic ally d ial 700 plus the 7-d ig it numb er to ac c ess 
the end p oints in the U.S. The c all is then routed  over d ig ital fac ilities in the AT&T 
network. End p oints c onnec ting  to this network with ISDN trunks rec eive 64 kb p s 
or multip les of 64 kb p s fac ilities while end p oints c onnec ted  with rob b ed  b it 
trunks rec eive 56 kb p s fac ilities. 
Following  are some ad d itional p oints to c onsider when using SDS and  S56 with 
the DEFINITY systems:
nThe c ost of SDS and  S56 has b een d ec lining  rec ently. It is p resently 
p ric ed  very c lose to that of analog  p rivate line servic es.
nSDS and  S56 are measured  servic es whose p rimary app lic ations are for 
b atc h d ata or file transfers that req uire only a c ertain amount of usag e 
eac h month. If the usag e is very hig h eac h month, then a p rivate line d ata 
servic e mig ht b e more ec onomic al. If the usage is for file transfer d uring  
one time p eriod  p er d ay, on the other hand , SDS or S56 mig ht b e more 
ec onomic al b ec ause the c ustomer is c harg ed  only for the usag e. Private  
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
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line servic e, on the other hand , is b illed  on a flat rate. This typ e of 
ap plic ation is well suited  for use with c all-b y-c all servic e selec tion in 
c onjunc tion with the usag e alloc ation p lan in G3V2 systems. For examp le, 
you c an resc hed ule your usage alloc ation plan to g ive hig her p riority to 
your batc h d ata transfers after b usiness hours.
nYou c an network AUDIX systems using 64 kb p s mod e 3 c ommunic ations 
over ISDN PRI trunks.
nOther imp ortant app lic ations are for hig h sp eed  fac simile, vid eo, and  
inq uiry/resp onse. These typ es of ap plic ations need  the hig h b and wid th 
b ut d o not c ontinuously use the same c ommunic ations link, and  thus d o 
not req uire d ed ic ated  lines. Vid eo telec onferenc ing  via SDS or S56 is 
becoming a popular application.
nCAD/CAM or g rap hic s terminals switc hed  throug h the DEFINITY systems 
is another app lic ation for this servic e.
nThe RS-449 p hysic al interfac e c an also b e used  with SDS and  S56, b ut 
ap plic ations for this re rare.
AT&T also offers ACCUNET Switc hed  Dig ital International (SDI) servic e, whic h is 
the international version of SDS. SDI offers 56 kb ps or 64 kb p s ISDN PRI servic e 
on a per-c all b asis b etween the U.S. and  other c ountries. Note that if the 64 kb p s 
version is used, the data must be c oded as unrestricted in the information 
transfer c ap ab ility (ITC) c od ep oint of the Bearer Cap ab ility IE. 
SDS and  SDI c alls use the same Network Sp ec ific  Fac ilities values (accunet
 in 
the network fac ilities ad ministration form).
MEGACOM Service
MEGACOM servic e is a WATS-like long  d istanc e servic e that uses sp ec ial 
a c c e ss  t o  t h e  4 ESS vi a  e it h e r  ro b b e d  b i t  t r u n ks  o r  D S1  I SD N  PRI  t r u n ks .  A n a l o g  
trunks c an also b e used , b ut these c alls are c onverted  to d ig ital b y a D4 c hannel 
b ank b efore reac hing  the 4ESS. This servic e is used when users on a PBX have a 
hig h volume of outgoing long  d istanc e c alls.
Bec ause the b illing  is d ifferent for WATS servic e and  MEGACOM servic e, if the 
volume ap p roac hes 800 to 1000 hours of c alls p er month, MEGACOM servic e 
mig ht b e more ec onomic al than WATS servic e. An international version of 
MEGACOM, called International MEGACOM servic e is also available. This 
servic es allows d irec t d istanc e d ialing  to other c ountries. If ISDN PRI trunks are 
used , b oth MEGACOM and  International Meg ac om share the same NSF value. 
An imp ortant ap p lic ation of MEGACOM servic e over ISDN PRI trunks is that the 
4ESS has the ab ility to keep  trac k of the c alling  p arty numb ers for b illing  
p urp oses b ec ause eac h c all has a c alling  p arty numb er information element in its 
SETU P m e s sa g e  id e n t i f yi n g  t h e  c a ll e r .  Wit h o u t  I SD N  PRI  t ru n k s,  t h e  4 ESS c a n  b il l 
only on a trunk g roup basis, forc ing  the PBX to keep  trac k of c all d etails. 
						

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MEGACOM 800 Service
MEGACOM 800 servic e is similar to Ad vanc ed  800 servic e (800 WATS). 
Meg ac om 800 c ustomers have the same op tions availab le with Ad vanc ed  800 
servic e, suc h as c ustomer c ontrollab le rerouting  of inc oming  c alls. The b ig g est 
d ifferenc e b etween the two servic es is that MEGACOM 800 uses trunks direc tly 
c onnec ted  to the 4ESS throug h sp ec ial ac c ess. These c an b e robb ed  b it trunks 
or DS1 ISDN PRI trunks. 
The p rimary reason to use MEGACOM 800 with ISDN PRI trunks is for d elivering 
the c alling partys billing number (BN, formerly called ANI) to telemarketing 
ap plic ations.
A c all d etail feature, ord erable throug h the loc al sales offic e, is availab le with 
MEGACOM 800. With this feature, a c all summary c an b e ob tained  on p ap er or a 
more d etailed  version c an b e ob tained on mag netic  tap e.
Dialed  Numb er Id entific ation System (DNIS) is availab le at no extra c ost with 
MEGACOM 800. This feature allows you to d ifferentiate one 800 c all from another 
on the same trunk g roup  b y p rovid ing  zero to seven d ig its, to the DEFINITY 
systems for eac h 800 c all. This is esp ec ially useful in telemarketing  ap p lic ations. 
For examp le, all inc oming  c alls to one typ e of numb er c an b e answered  with one 
messag e and  c alls to other numb ers c an b e answered  with a d ifferent messag e. 
To use this feature, the DEFINITY systems should  inc orp orate sp ec ial eq uip ment 
and /or software, suc h as d isp lay p hones, ACD, c all manag ement system, or c all 
d etail recording .
DNIS is esp ec ially well suited  for use with the inc oming  c all hand ling  tab le, 
ad ministered  in the trunk g roup  form. The inc oming  c all hand ling  tab le c an 
sc reen eac h c all b ased  on the d ig its rec eived  and  d o any of the following :
nAd d  and /or d elete d ig its to route the c all to a sp ec ific  destination, suc h as 
a hunt g roup  or an AAR p attern.
nRequest CPN/BN be delivered for selected calls.
nProvid e sp ec ial nig ht treatment for selec ted c alls.
An international version of MEGACOM 800 servic e, c alled  International 800 
service, is also availab le. Unlike the other services, the NSF values for 
MEGACOM 800 and  International 800 are d ifferent. Thus, if you use b oth 
International 800 and  MEGACOM 800 over ISDN PRI trunk g roup s, you must p ut 
them on c all-b y-c all trunk g roup s or on sep arate trunk g roup s.
Software Defined Network and 
Software Defined Data Network
Software Defined  Network (SDN) servic e allows end p oints on the DEFINITY 
systems to c ommunic ate with end p oints on other PBXs as if the PBXs were 
c onnec ted  in a p rivate network arrang ement suc h as Elec tronic  Tand em  
						

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Network. SDN c an b e ac c essed  b y rob b ed  b it trunks or DS1 ISDN PRI trunks 
d i re c t ly  c o n n e c t e d  t o  t h e  4 ESS t h ro u g h  sp e c ia l a c c e ss .  SD N  c a n  a ls o  b e  
ac c essed  b y b eing  switc hed  throug h the LEC offic e to the 4ESS. This typ e of 
ac c ess, thoug h, is not p rac tic al for a PBX b ec ause eac h extension on the PBX is 
c harg ed  for the ac c ess. Following  are some relevant SDN issues: 
nSDN sup ports either a 7-d ig it or a 10-d ig it p rivate network dial p lan.
nSDN d oes not tand em traveling  c lass marks (TCMs) on c alls over rob b ed  
b it trunks b ut does tandem them on ISDN PRI trunks.
nSDDN with ISDN provid es 56 kbp s, 64 kb ps, 384 kb p s, and 1.536 mb p s 
digital service end-to-end. You must tell the 4ESS in the order form which 
extensions are to rec eive the all-d ig ital servic e. The c alled  p arty numb er is 
used by the network to route the call.
nWhen temp orary sig naling  c onnec tions (TSCs) are tariffed , G3V2 systems 
will b e ab le to form a DCS network b y p utting  the DCS sig naling  c hannel 
on an ISDN PRI D c hannel and  using  SDN for the network trunks. This will 
enab le those not having  a DEFINITY p rivate network (a network b ased  on 
AAR software in G2.2 and  G3V2 or Main/Satellite software in G2.2) the 
ab ility to have a DCS network.
nThe Lookahead  Interflow feature, whic h also normally req uires AAR 
software, c an b e imp lemented  using  DS1 ISDN PRI trunks with SDN 
servic e.
For d ata ap p lic ations, Software Defined  Data Network is available. This servic e 
emp loys the same features as SDN, b ut uses all-d ig ital fac ilities and  also 
p rovid es an auto restoration feature that automatic ally restores a c onnec tion that 
has b een b roken. The G3V2 systems imp lements this auto-restoration c ap ab ility 
in the administered connec tion form. If you administer a connec tion to SDDN 
over an ISDN PRI trunk with a servic e typ e of sdd n, you c an selec t the 
auto-restoration capability. An international version of SDN, c alled Global SDN is 
also availab le. Glob al SDN allows c ustomers to c reate virtual p rivate networks 
sp anning  many c ountries, c urrently inc lud ing  Australia, the U.K., Jap an, Franc e, 
and  Canad a. It d oes this b y interworking  SDN with the virtual p rivate networks 
offered  in these other c ountries. Another international SDN servic e is SDN 
International (SDN-I). SDN-I is not a g lob al network like Glob al SDN, b ut is SDN 
with the ab ility to c all over 177 other c ountries via the SDN.
Private Network Applications 
Any p rivate network ap p lic ations utilizing tie trunks c an b e imp lemented  with 
d ig ital trunks. These inc lud e ap p lic ations suc h as Elec tronic  Tand em Networks 
(ETN) and  ETN with Distrib uted  Communic ation System (DCS). Fac ilities 
sup p orting CEPT1 CAS trunks or CEPT1 ISDN PRI trunks are limited  in most 
areas of the U.S. If CEPT1 fac ilities are not available, the only way to form a 
p rivate network with CEPT1-b ased  trunks is b y d irec tly c onnec ting  the systems 
or by using  p rivate mic rowave systems that sup port the CEPT1 stand ard . Tie 
trunks requiring only 56 kbps can be implemented with robbed bit signaling or  
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
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Applications 
Page 2-12 Private Network Applications 
2
ISDN PRI signaling while those requiring 64 kbps must be implemented with CAS 
trunks, DS1 c ommon c hannel trunks, or ISDN PRI trunks. DCS sig naling  links c an 
b e implemented  with CAS trunks, with ISDN PRI trunks, and  over ISDN PRI D 
c hannels. If a DCS sig naling  link is imp lemented  over an ISDN PRI D c hannel, 
p ublic  network ISDN PRI trunks c an b e used  to c arry that sig naling  information to 
the far end  system. For example, if several systems are networked  together using  
SDN (AT&Ts virtual private network servic e) over DS1 ISDN PRI sp ec ial ac c ess 
trunks, DCS sig naling  links c an be installed  over the D c hannels for those trunks, 
thus p roviding  DCS func tionality without the need  to install p rivate lines, as in an 
ETN. Other ad vantages of using  the D c hannel to c arry the DCS sig naling  are as 
follows:
nThis method  saves p roc essor interfac e links on G3i systems. These links 
are p rec ious resourc es sinc e there are only a maximum of eig ht per 
system.
nThe signaling  c hannel on an ISDN DCS link c an hop  from one link to any 
other link whereas the sig naling  c hannel on a G3i X.25 DCS link c an hop  
only to a c hannel on one of the four links on the same PI b oard .
nThe p rob lems enc ountered  when trying  to keep  the DCS trunks numb ered  
the same at eac h end  g o away. This is b ec ause DCS over the D c hannel 
keep s trac k of its assoc iated  trunks with the c all referenc e value 
information element in an ISDN PRI messag e.
nA trunk that would  otherwise have to b e used  for the DCS sig naling  link 
c an now b e used  as a voic e or d ata trunk.
NOTE:
The G3V2 systems sup p ort d ialing  with trunk ac c ess c od es to ISDN PRI 
trunk g roup s, but G2.2 d oes not. 
						

							Equipment and Software Requirements 
Page 3-1  
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DS1/CEPT1/ISDN PRI Reference  
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July 1993
3
3Equipment and Software 
Requirements
This c hap ter p rovid es ordering  information for eq uip ment and  software req uired  
in typic al configurations using DS1 and CEPT1 fac ilities. It also provides 
c onnec tivity information and  hard ware switc h setting s.
The following  tab les summarize the req uired  equip ment and  software. Note that 
when a suffix ap p ears, that is the earliest suffix and /or vintag e req uired . For 
examp le, TN464C means all TN464s with suffix C or later will work.