Patton electronic RocketLink-G NTU Rack Mount G.SHDSL Modem Card S2-4 through S2-5 Clock Mode

S2-4 through S2-5: Clock Mode

The RocketLink-G can operate in one of three clock modes: internal, external, or receive-recover.

S2-4	S2-5	Clock Mode	Description
ON	ON	Internal	The on-board oscillator in
			the 3088RC provides clock
			for both serial and DSL lines.
OFF	ON	External	3088RC uses the RX clock
			from the serial interface as
			the clock for the DSL link.
ON	OFF	Receive-	3088RC uses the RX clock
		Recover	from the DSL line as the
			clock for the serial interface.
OFF	OFF		Reserved

X.21 operation. There are a few things to note about clock modes and X.21 operation.

—One X.21 modem must be set to Receive-Recover.The other X.21 modem must be set to either Internal or External/Network clock mode.

—The X.21 modem that is conÞgured as Receive-Recovermust be DCE.

—The X.21 modem that is conÞgured as Internal must also be DCE, but if it is an External/Network clock, then the modem must be conÞgured as DTE.

	CPE-Side Modem	CO-Side Modem
Modem’s X.21	Receive-Recover	Internal	External/Network
Orientation
	DCE	DCE	x
	DCE	x	DTE

Ethernet operation. The 3088RC/C/AI model does not recover clock from the Ethernet network because it is packet-based rather than TDM. Therefore, the external clock mode is not valid.

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