Lucent Technologies DEFINITY Communications System Generic 2.2 And Generic 3 V2 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 4-47 Synchronization 
4
nYellow LED is on 2.7 sec ond s and  off 0.3 sec ond s — the tone-c loc k 
sync hronizer is in “ ac tive”  mod e and an external sync hronization sourc e is 
b eing  used  as a sync hronization referenc e.
nYellow LED is on 0.3 sec ond s and  off 2.7 sec ond s — the tone-c loc k 
sync hronizer is in “ ac tive”  mod e and  the internal...

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 4-48 Synchronization 
4
Criteria for Switching Back to the Primary Reference
Eac h time the master tone-c loc k sync hronizer rep orts a LOS, it inc rements the 
exc essive referenc e switc h c ounter. If a total of 20 switc hes oc c ur within a 1-hour 
interval then the internal (on-b oard ) hig h-ac c urac y c loc k is p lac ed  online and 
automatic  referenc...

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 4-49 Synchronization 
4
Figure 4-11. Public-Network and External Stratum-3 Clock Connection to G2.2
By rep lac ing  the TN463 with a TN2131 in the same slot, the G2.2 may also use 
the external stratum-3 c loc k.
Most Generic  2.2 and  Generic  3V2 c ommunic ations systems will use the external 
c loc k. This c loc k is p hysic ally mounted  external to the switc...

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 4-50 Synchronization 
4
terms of ap p lic ation, the external c loc k c onnec ts b etween the NCTEs and  the 
switc h. Cab ling  for the I/O and alarm c onnec tions is via 25-p air c ab les with 
50-p in telep hone c onnec tors. The NCTE-to-external c loc k c onnec tion has the 
same d istanc e limitations as the NCTE-to-DS1 c onnec tion (655 feet maximum).
For...

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 4-51 Synchronization 
4
Figure 4-12. G3V2 Connections to the External Stratum 3 Synchronization Clock
cydfg3v2 RPY 060597
Stratum 3
external
synchronization
clockYe l l o w f i e l d
cross-connect
Designator
cableCabl e
typeAA
A
C
CY
Y Y
Y Y
Y B
BTN780 A Carrier
B Carrier
Primary
Secondary
A
B
C
YB25A
C60
C6E
H-600-274TN780
DS1
DEFINITY generic 1 or 3
System end...

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 4-52 Synchronization 
4
Figure 4-13. External Clock Connection to G3V2 or G2.2
Private network ap p lic ations that d o not have d ig ital c onnec tions to stratum-3 or 
b etter referenc e sourc es will not p rovid e the 
Re f e re n c e  1 and  Refe ren c e 2 inp uts 
or the c loc k-inp ut #1 and  c loc k-inp ut #2 c irc uit p ac ks. These typ es of network 
ap...

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 4-53 Synchronization 
4
Figure 4-14. G2.2 External Stratum-3 Clock Interface
Figure 4-15. G3V2 External Stratum-3 Clock Interface
cydfg22x RPY 060497
Composite
clock
converterLOS
detectionAlar ms
Sync
output
Composite
clock
output A
Composite
clock
output B
Note 1
Note 2Backplane signal
to TMS or modul
econtrol clock TN2131 circuit pack
Notes:
1. Alarm signals...

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 4-54 Synchronization 
4
Figure 4-16. External Stratum-3 Clock Duplicated Synchronization for G3V2 or G2.2
Network Synchronization and Engineering
The p rimary g oals of network sync hronization are:
nTo keep each digital network node reliable
nTo make sure that eac h d ig ital termination c an meet the network 
ob jec tives
With the g rowth in the number of d ig...

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 4-55 Synchronization 
4
A sync hronization p lan c an also b e desig ned  b y using  the following guid elines 
and  rules.
nEnsure that all nod es and  fac ilities are sync hronized to a sing le sourc e of 
timing ; or at the worst, to two or more stratum-2 timing  sourc es
nSelec t the most reliab le d ig ital fac ilities to serve as sync hronization 
referenc...

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 4-56 Synchronization 
4
Figure 4-17. External and Internal Reference Levels
For externally referenc ed  nod es, the op erating  c omp any p ersonnel will sp ec ify 
what the sourc e of timing  is on those links. If the network d oes not rec eive timing  
from the pub lic  network at any of its nodes, the master-slave relationships in the 
network will then b e d...