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
Physical Layer 
Page 4-7 Framing Format 
4
Tab le 4-1 illustrates these p oints:
Notes:
1. C1 throug h C4 =  CRC-4 b its
2. U =  Unassig ned  b it
3. Yf =  Remote frame alarm b it
4. E =  Remote end  b loc k error b its
G2.2 Framing Format Implementation
In G2.2 you selec t either ESF or D4 framing  in p roc ed ure 260, word  1, field  6.
Table 4-1. 2.048 Mbps CEPT1 in Channel 0
FramesBits in channel 0
1 2 345678
0 C1 0 011011
1 0 1 YfUUUUU
2 C2 0 011011
3 0 1 YfUUUu U
4 C3 0 011011
5 1 1 YfUUUUU
6 C4 0 011011
7 0 1 YfUUUUU
8 C1 0 011011
9 1 1 YfUUUUU
10 C2 0 011011
11 1 1 YfUUUU
12 C3 0 011011
13 E 1 YfUUUUU
14 C4 0 011011
15 E 1 YfUUUUU 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-8 Companding 
4
G3V2 Framing Format Implementation
If you administer the DS1 bit rate, the G3V2. supp orts D4 and  ESF as op tions in 
the S1 c irc uit p ac k form. You should  use ESF if p ossib le. The p rimary reason for 
this is for reframing  after a misframe. ESF automatic ally reframes whereas D4 
d oes not. This ab ility to reframe is esp ec ially c ruc ial in d ig ital d ata 
c ommunic ations. You must sp ec ify ESF framing on the servic e ord er form if you 
are using  a Network servic e in the U.S. You must also op tion ESF on the CSU. If 
D4 framing  is used , the far end  and  the CSU must also use D4-framing for that 
DS1 interfac e.
To ad minister framing , enter either esf
 or D4
 in the 
Fr a m i n g  M o d e field  on the 
DS1 Circ uit Pac k form.
If the 2.048 mb ps option is ad ministered , no op tion app ears on the form, 
meaning CEPT1 framing is automatically administered. 
Companding
Comp and ing  is a method  of imp roving  the sig nal-to-noise (S/N) ratio resulting  
from the pulse c od e mod ulation (PCM) p roc ess on voic e c alls. It is availab le as 
an ad ministration option only on G3V2 systems. Furthermore, it c an b e 
ad ministered  for lines and  for trunks. This d oc ument c onsid ers only the 
imp lementation of trunk c omp and ing .
To understand  c omp and ing , you must first und erstand  PCM. During  PCM, 
samp les of the sig nal amp litud e are taken at reg ular intervals. The amplitud e of 
eac h samp le is first dig itized  (q uantized ) and then round ed  up. This round ing 
op eration c auses q uantization noise. The q uantization noise is p rop ortionately 
greater at lower amplitudes.
With c omp and ing , the analog  signal’s amp litud e range is c omp ressed  b efore it is 
q uantized  and  transmitted . The q uantized  sig nal is exp and ed  b y a sp ec ial PCM 
d ec od er after it is rec eived . With d ig itized  transmission, c omp and ing  amounts to 
assig ning  a small unit of q uantization noise to lower amp litud es and  larger units 
to hig her amp litud es. This red uc es the amount of q uantization noise.
Either of two algorithms are used  to c ompand  voic eb and  sig nals: A-law and  
mu-law. A-law is g enerally used  in c ountries that use CEPT1 transmission at 
2.048 mb p s; while mu-law c omp and ing  is used  in c ountries with DS1 
transmission at 1.544 mb p s. When transmitting  internationally, the A/mu-law 
c onversion is p erformed  at the same time the DS1/CEPT1 c onversion is d one. 
The following  tables summarize the c omp anding  sup p ort in d ifferent c ountries at 
this time: 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-9 Companding 
4
1. Excep t Cairo, whic h uses mu-law c omp and ing  at the CEPT1 bit 
rate.
Table 4-2. Countries Supporting A-Law Companding at the CEPT1 Bit Rate
European
Belg ium Czechoslovakia Franc e
Germany Greec e Hung ary
Italy Netherland s Russia
Sp ain Switzerland U.K.
Pacific Rim
Australia China Ind ia
Ind onesia New Zealand Philip p ines
Sing ap ore Thailand
Americas
Brazil Costa Ric a Mexic o
Middle East
Eg y p t
1Saud i Arab ia
Table 4-3. Countries Supporting mu-Law Companding at 1.544 Mbps Only
Pacific Rim
Hong  Kong
Ta i w a n
Americas
Canad a Dominic an Rep ub lic Puerto Ric o
United  States Venezuela 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-10 Channel Structure and Signaling 
4
Any DEFINITY system using  any DS1 interfac e board  other than the TN464C or 
later is mu-law b y d efault and  c annot b e c hang ed  in ad ministration.If a TN464C 
or later is used  on a G3V2, however, c omp and ing  is ad ministrab le. The following  
field  ap p ears on the DS1 c irc uit p ac k form:
NOTE:
A system c an c onsist of b oth A-law and  mu-law interfac es. Thus, c alls 
inc oming  on A-law fac ilities c an be switc hed  to outg oing  mu-law fac ilities 
and  vic e versa.
Channel Structure and Signaling
The p hysic al layer asp ec ts of c hannel struc ture and  sig naling  are imp lemented  
in the d ig ital trunk b oard s in the DEFINITY systems. The DS1 b it stream is 
time-multip lexed  into 24 64 kbp s c hannels. The CEPT1 b it stream is 
time-multip lexed  into 32 64 kbp s c hannels. Within this b asic  c hannel struc ture, 
variations in sig naling  exist. Following are the typ es of sig naling  availab le on DS1 
boards:
nBit-oriented signaling, which is further divided into the following types:
— Robbed bit signaling
— Common c hannel sig naling , whic h is further d ivid ed  into the 
following types:
nAT&T Proprietary c ommon c hannel sig naling
nDMI-BOS c ommon c hannel sig naling
nISDN PRI sig naling Table 4-4. Countries Supporting mu-Law Companding at both
DS1 and CEPT1 Bit Rates
Jap an
Korea
Venezuela
Interface 
Companding:This field  c an be set to either alaw
 or mulaw
. Both end s of the 
DS1 or CEPT1 span must have the same c omp and ing. 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-11 Channel Structure and Signaling 
4
Following  are the CEPT1 signaling  typ es:
nBit oriented  c ommon c hannel sig naling , whic h inc lud es only one type 
c alled  c hannel assoc iated  sig naling  (CAS)
nISDN PRI sig naling
Robbed-Bit Signaling
Rob b ed -b it sig naling (RBS) may b e used  over DS1 1.544 mb p s fac ilities. With 
RBS, in every 6th frame the sig naling  alg orithm replac es (that is, “ rob s” ) the 
least-sig nific ant b it (LSB) of eac h c hannel. It rep lac es this b it with the sig naling  
information for that c hannel. For the sup erframe format, the 6th and  12th frames 
c arry RBS; for ESF, the 6th, 12th, 18th, and  24th frames c arry RBS.
Eac h sig naling  frame alternates b etween the A b it and  the B b it. Thus, the 6th 
frame c arries the A b it, the 12th the B b it, and  so on.
Bec ause the sig naling  information is c arried  emb ed d ed  within eac h c hannel, 
RBS sig naling  is also c alled 
inband signaling.
Sinc e not all eig ht bits of every b yte c an b e used  b ut seven b its of every b yte c an 
b e used , rob bed  b it c hannels ad ministered  as trunks c an c arry information of no 
more than 56 kb p s. This allows voic e, voic e-g rad e d ata and  mod e 1 d ig ital d ata 
to b e transp orted  on rob b ed  b it fac ilities. 
DS1 Common Channel Bit Oriented Signaling
Common c hannel sig naling  on DS1 fac ilities p lac es the sig naling b its (the A and  
B b its) into the 24th c hannel. This p ermits the c hannels to use their full 64 kb p s 
b and wid th c apac ity b ec ause no b its are rob b ed  from the information-b earing  
c hannels (the trunk c hannels). Thus, this typ e of sig naling  p rovid es 23 64-kb p s 
c hannels for voic e or d ata transmission, with the 24th c hannel reserved  for 
signaling only. 
The format used to c arry sig naling  information req uires 24-frames, a req uirement 
met b y ESF. For the D4 sup erframe format to meet this req uirement, however, 
two D4 sup erframes are linked  together to form the req uired  24-frame 
sup erframe. Within 24th-c hannel b it-oriented  sig naling , there are two variations: 
nAT&T prop rietary sig naling
nDMI BOS (bit-oriented signaling)
AT&T prop rietary sig naling  was the first typ e of 24th-c hannel sig naling  provid ed  
b y System 75 and  System 85. It was d evelop ed  to c arry DCP-formatted  d ata (in 
d ig ital form) b etween System 75 and /or System 85 switc hes. AT&T p roprietary 
sig naling  is d esc rib ed  in the initial release of the DMI technical sp ecification 
(selec t c od e 500-029).  
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-12 Channel Structure and Signaling 
4
For AT&T p roprietary signaling , a c omp lete set of sig naling  information is sent 
every 24 frames. This 24-frame period  is not sync hronized  to the 12-frame 
sup erframe (D4) format or to the 24-frame extend ed  sup erframe (ESF) format. 
Eac h sig naling  b yte c ontains the eq uivalent of a c hannel id entific ation numb er 
and  the sig naling  state for that c hannel. The c hannel id entific ation numb er is 
nec essary sinc e the c hannel sig naling  information may not b e sync hronized  with 
the voic e or d ata c hannel that it d esc rib es.
Some typ es of p ub lic  network eq uip ment were inc omp atib le with this typ e of 
24th-c hannel sig naling  and , as a result, another typ e of 24th-c hannel sig naling , 
called DMI bit-oriented signaling (DMI-BOS), was developed. For DMI-BOS, 
sp ec ific  24th-c hannel b it loc ations c arry framing  and  alarm d ata, and sig naling 
information for the other 23 c hannels. Unfortunately, DMI-BOS and  AT&T 
p rop rietary sig naling  are not c omp atib le. DMI-BOS must b e used  for c onnec tions 
to host c omputers and  other vend ors’ eq uip ment that meets the DMI tec hnic al 
sp ec ific ation for BOS. Ta b l e  4 - 5
 illustrates the c hannel struc ture of a DMI-BOS 
interfac e:
Table 4-5. 1.544 Mbps DMI-BOS in Channel 24
FramesBit in channel 24
12345678
1A13A1B1X X X 1 X
2A14A2B2X X X 1 X
3A15A3B3X X X 1 X
4A16A4B4X X X 1 X
5A17A5B5X X X 1 X
6A18A6B6X X X 1 X
7A19A7B7X X X 1 X
8A20A8B8X X X 1 X
9A21A9B9X X X 1 X
10 A22 A10 B10 X X X 1 X
11 A23 A11 B11 X X X 1 X
12 1 A12 B12 X X X 1 X
13 A1 A13 B13 X X X 1 X
14 A2 A14 B14 X X X 1 X
15 A3 A15 B15 X X X 1 X
Continued on next page 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-13 Channel Structure and Signaling 
4
Notes:
1. .X =  Reserved  for future use. Set to 0.
2. RMA =  Remote multiframe alarm (0 =  alarm; 1 =  normal)
3. Bit 7 =  Primary b it p attern for sig naling  integ rity check
4. Bits 3, 4, 5, and  8 in frame 24 =  Sec ond ary b it p attern for sig naling  integ rity check
5. A and B = Signaling bits for indicated channels.
6. The TN722 supp orts only AT&T proprietary signaling. However, the TN722B c an 
b e ad ministered  to sup p ort either AT&T p rop rietary sig naling  or DMI-BOS.
7. The TN767 on G3iV2. c an b e ad ministered  for either DMI-BOS or ISDN-PRI 
sig naling . For the G3rV2, the TN767 is reserved  for DMI-BOS sig naling , while the 
TN464C c an be administered  for either ISDN-PRI or DMI-BOS sig naling .
CEPT1 Common Channel Bit-Oriented Signaling
CEPT1 b it oriented  sig naling  uses the 16th c hannel to c arry sig naling  information 
for the other 30 c hannels (rob b ed  b it sig naling d oes not exist in CEPT1). This 
p ermits the c hannels to use their full 64 kb p s b and width c ap ac ity. CEPT1 
fac ilities use only one type of bit oriented  sig naling , c alled  c hannel assoc iated  
sig naling  (CAS). With CAS, c hannels 1 throug h 15 and  17 through 31 are used  
for voic e and data transmissions and  c hannel 0 is used  for framing  (see CEPT1 
Fra mi ng ).16 A4 A16 B16 X X X 1 X
17 A5 A17 B17 X X X 1 X
18 A6 A18 B18 X X X 1 X
19 A7 A19 B19 X X X 1 X
20 A8 A20 B20 X X X 1 X
21 A9 A21 B21 X X X 1 X
22 A10 A22 B22 X X X 1 X
23 A11 A23 B23 X X X 1 X
24 A12 1 1 1 0 RMA 0 1
Table 4-5. 1.544 Mbps DMI-BOS in Channel 24 — Continued
FramesBit in channel 24
12345678
Continued on next page 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-14 Channel Structure and Signaling 
4
Like CEPT1 framing , CAS sig naling is c yc led  throug h sixteen (0-15) frames (eac h 
c ontaining  c hannels 0-31), as shown in Ta b l e  4 - 6
:
Notes:
1. X =  unused  b it to b e set to 1.
2. Y =  b it used  to ind icate multiframe alig nment.
3. 0000 =  In b its 1 through 4 of frame 0. Multiframe alig nment sig nal.
4. Bits 1, 2, 5, and  6 are the A and  B b its used  for forward and b ackward  sig naling in 
time slots numb ered  ag ainst them.
5. Bits 3 and  7 are the C b its. All C b its are set to 0 in transmission and  ig nored  b y the 
rec eiver.
6. Bits 4 and  8 are the D b its. All D b its are set to 1 in transmission and  ig nored  b y the 
rec eiver.
Table 4-6. 2.048 Mbps CAS in Channel 16
FramesBit in channel 16
123456 7 8
00000XYXX
1A1B1C1D1A17B17C17D17
2A2B2C2D2A18B18C18D18
3A3B3C3D3A19B19C19D19
4A4B4C4D4A20B20C20D20
5A5B5C5D5A21B21C21D21
6A6B6C6D6A22B22C22D22
7A7B7C7D7A23B23C23D23
8A8B8C8D8A24B24C24D24
9A9B9C9D9A25B25C25D25
10 A10 B10 C10 D10 A26 B26 C26 D26
11 A11 B11 C11 D11 A27 B27 C27 D27
12 A12 B12 C12 D12 A28 B28 C28 D28
13 A13 B13 C13 D13 A29 B29 C29 D29
14 A14 B14 C14 D14 A30 B30 C30 D30
15 A15 B15 C15 D15 A31 B31 C31 D31 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-15 Channel Structure and Signaling 
4
Note that exc ep t for frame 0, the 16th c hannel of eac h frame hold s the sig naling  
for two voic e/d ata c hannels. The sig naling  is held  in p ositions A throug h D. For 
examp le, the 16th c hannel of frame 2 hold s the sig naling  bits (bits A throug h D) 
for voic e/d ata c hannels 2 and  18. The 16th c hannel of frame 0 c arries the 
multiframe alignment sig nal (0000) in b its 1 throug h 4 and  an alarm ind ic ation in 
bit 6.
ISDN PRI Signaling
ISDN PRI sig naling is a form of messag e oriented  sig naling  in whic h a c ommon 
sig naling  c hannel c arries multib yte messag es for sig naling .
Both DS1 and  CEPT1 reserve a c ommon c hannel for ISDN PRI signaling . In DS1 
fac ilities, the 24th c hannel is reserved  for ISDN PRI sig naling  while in CEPT1 
fac ilities the 16th c hannel is reserved. Unlike b it-oriented  sig naling , this c hannel 
is left unformatted at the p hysic al layer so that it c an b e used  b y hig her level 
p rotoc ols to carry messag es.
NOTE:
The p ub lic  network ISDN PRI in Australia (Country op tion 2) map s CEPT1 
c hannels 1-31 to ISDN PRI B c hannels 1-30. This means that systems 
interfac ing  to the p ublic  network in Australia will be inc orrec tly map p ed  
from c hannels 17-31. Using  c ountry op tion 2 c ompensates for this 
map p ing . For d etails on this sub jec t, see the sec tion ‘‘Channel ID IE’’
 in 
Chap ter 5, ‘‘Layers 2 and  3’’
.
G2.2 Signaling Implementation
G2.2 imp lements the physic al layer asp ec ts of DS1 sig naling  in p roc ed ure 260, 
word  1, field s 7, 8, 14, and  19 as follows:
nFor trunks using robbed bit signaling, field 7=blank
, field  8=1
, field  14=0
, 
field  19=dash
.
nFor trunks using  AT&T p rop rietary c ommon c hannel b it-oriented  sig naling , 
field  7=blank
, field  8=0
, field  14=0
, 19=1
.
nFor trunks using DMI-BOS c ommon c hannel b it-oriented  sig naling , field  
7=blank
, field  8=0
, field  14=1
, 19=0
.
nFor trunks using ISDN PRI signaling, field 7=0
 if it is a FAS b oard or 1
 if it is 
an NFAS board  with all B c hannels, field 8=0
, field  14=5
, 19=dash
.
NOTE:
On Generic  2.2 trad itional mod ules, the ANN11B and  ANN11C supp ort only 
AT&T p rop rietary sig naling . The ANN11D and  ANN11E sup p ort b oth AT&T 
p rop rietary sig naling  and  DMI-BOS. They d efault to DMI-BOS, b ut 
automatic ally switc h to AT&T prop rietary sig naling  whenever the d istant 
end  is using  AT&T p rop rietary sig naling . 
						

							DEFINITY Communications System Generic 2.2 and Generic 3 V2 
DS1/CEPT1/ISDN PRI Reference  
555-025-107  Issue 1
July 1993
Physical Layer 
Page 4-16 Channel Structure and Signaling 
4
G3V2 Signaling Implementation
The following  field  ap p ears in the DS1 c irc uit p ac k form:
If you administer c ommon c hannel sig naling , you must also c omp lete the 
following  field on the DS1 c irc uit p ac k form:Signaling Mode:
Enter either robbed-bit
, common-chan
, or isdn-pri
, CAS
, 
or isdn-ext
. Ad ministering  robb ed  b it signaling  on a DS1 
interfac e yield s 24 information c hannels c ap ab le of 
c arrying  voic e or 56 kb p s d ata. You c an ad minister some 
c hannels on a DS1 interfac e to b e rob b ed -b it c hannels and  
the rest of the c hannels on the interfac e as ISDN PRI 
c hannels. To d o this, you must ad minister the DS1 Circ uit 
Pac k form as isdn-pri
. When you sub seq uently ad d p orts 
on the interfac e to a trunk g roup , those p orts that are 
ad ded  to non- ISDN PRI trunk g roups automatic ally 
b ec ome robb ed  b it trunks. Note, however, that this 
c ap ab ility is not sup ported  on the CEPT1 interfac e.
DMI-BOS?
If you enter y
 here, you g et DMI-BOS sig naling . If you 
answer n
, you g et AT&T p rop rietary sig naling . In either 
c ase, you g et 23 64 kb p s information c hannels p er DS1 
interfac e that c an eac h b e ad ministered as trunks to b e 
used  for voic e, mod e 0, mod e 1, mod e 2, or mod e 3 d ata. 
CAS is c hannel-assoc iated  sig naling  (CAS), whic h is a 
form of c ommon c hannel sig naling . The op tion isdn-ext
 
d esig nates that the D c hannel sig naling  for this b oard  is on 
another b oard  and  that this b oard  c ontains all B c hannels. 
Tab le 4-7
 summarizes how to ad minister the c irc uit p ac ks 
to generate the type of signaling indicated: