ISDN Interfaces
Timing and Synchronization
Strata DK I&M 6/00
16-39
ISDN
Inte
rface
s
Figure 16-30 Loop-back Test
Timing and Synchronization
The Digital Network is connected by timing clocks that synchronize the network and have various
degrees of precision (stratum levels). There are four stratum levels – 1 is the highest and 4 is the
lowest. They are associated with the following sources:
♦
Stratum – 1
: Public Telephone Network clock
♦
Stratum – 2
: #4 ESS Toll Switches
♦
Stratum – 3
: #5 ESS Central Offices
♦
Stratum – 4
: Digital PBXs
In the DK424 or DK424i, one PRI, BRI, or T1 PCB can be programmed to extract the Stratum
clock signal. It uses the signal as the DK system Primary clock reference. The clock provider
should be a reliable source, such as a Telco or common carrier (AT&T). All other PRI, BRI, or T1
lines connected to the DK424 or DK424i will be synchronized to the same clock provider. If the
PRI, BRI, or T1 are not synchronized to the same clock provider, the DK424 or DK424i could
experience “slip” problems.
Timing reference assignments for PRI, BRI, and T1 are made with the Program *42 series. The
timing or synchronization program determines how the DK424 or DK424i digital voice or data
transmission path is synchronized with the far-end digital path. For proper PRI, BRI, and T1
operation, the equipment at each end of the line must be synchronized.
The DK processor time switch is synchronized as the slave to the PRI, BRI, or T1 line (Line 1 in
). The DK424 or DK424i PRI, BRI, or T1 in any slot number can be assigned as the
Primary reference (Program *42-1, DATA=1 for this PRI, BRI, or T1).
If a malfunction occurs and Primary reference synchronization is lost, the DK424 or DK424i
automatically switches modes and synchronizes to the Secondary reference, provided that there is
another PRI, BRI, or T1 installed in the DK system. The Secondary reference PCB is assigned in
Program *42-2.
CO ISDN
PRI Test
Signal
ISDN PRI
CSU
ISDN PRI
(RJ-45)
JP1
(LB-ON)
JP2
(LB-ON)
1.5MHz
line
Interface
LSI
Demarcation Point
2756
RPTU
Network
Jack
RJ-48C
or RJ-48X
Summary of Contents for Strata AirLink DK40i
Page 22: ...Introduction Related Documents Media xx Strata DK I M 6 00 ...
Page 48: ...DK14 Installation DK14 Wiring Diagrams 1 26 Strata DK I M 6 00 ...
Page 220: ...DK424 Installation Remote Cabinet Installation Instructions 5 68 Strata DK I M 6 00 ...
Page 262: ...DK424i Configuration Primary Reserve Power Cabinet Hardware 6 42 Strata DK I M 6 00 ...
Page 450: ...Universal Slot PCB Wiring Option Interface PCB Wiring Diagrams 10 42 Strata DK I M 6 00 ...
Page 592: ...Peripheral Installation Enhanced 911 Service E911 12 84 Strata DK I M 6 00 ...
Page 616: ...ACD Installation Spectrum Electronic Wall Boards 13 24 Strata DK I M 6 00 ...
Page 634: ...Fault Finding Fault Isolation Flowcharts 14 18 Strata DK I M 6 00 ...
Page 704: ...ISDN Interfaces ISDN Disconnect Cause Code 16 54 Strata DK I M 6 00 ...