Paradyne 8777, 8747, 8779, Hotwire M/SDSL and HDSL2 Termination Units manual System Clock

Configuration Options

System Clock

The Primary and Secondary System Clock References determine the clock used by ports in a cross-connect configuration. For System Clock configuration options, refer to Table A-8. To access the System Clock screen, follow this menu selection sequence:

Main Menu → Configuration → Load Configuration From → System

main/config/system_clock
Slot: 18	Model: 87xx
SYSTEM CLOCK
Primary System Clock Reference	Internal
Secondary System Clock Reference	Internal

––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

Ctrl-a to access these functions, ESC for previous menu	MainMenu Exit
Save

All ports configured as system clock sources must be traceable to the same clock reference. Ports in a cross-connect configuration that are not providing timing themselves receive their timing from the system clock reference. All ports in a cross-connect configuration are therefore synchronized to the system clock reference.

The following table shows the system clock reference combinations permitted for LTUs and NTUs. Choose the most accurate clock available for the Primary

System Clock Reference.

Device	If the Primary System Clock	The Secondary System Clock
	Reference is . . .	Reference must be . . .
LTU	DSX-1 or G.703 port in	H DSX-1 or G.703 port in DS1 Bypass
	cross-connect mode	mode, or
		H Internal
	DSX-1 or G.703 port in DS1	H DSX-1 or G.703 port in DS1 Bypass
	Bypass mode	mode, or
		H Internal

Internal

Internal

NTU

DSL port in cross-connect mode	DSL port in cross-connect mode
Internal	Internal

8700-A2-GB20-00 April 2000 A-13