User guide

4-22 DL3800 DS1 Inverse Multiplexer User Guide—February 1999

Primary Clock Source This allows the user to select either the Primary Clock Source, transmit (xmt),

and receive (rcv) for the individual T1 network ports.

To change the present Primary Clock Source, use the up and down arrow

keys to highlight either Xmt or Rcv on the Primary Clock Source line, and

use the Space Bar to toggle between the choices. For Xmt (transmit) the

choices are Network (NET), External (EXT), and Internal (INT). For Rcv

(receive) the choices are Net-1 through Net 8 (each of the individual T1

network ports), or Auto (the unit selects the best source).

The DL3800 can use several sources to generate the transmit clock. The

Internal selection uses an oscillator within the DL3800, the Network setting

recovers the clock from the selected T1 line, and the External setting

recovers the clock from the dB-9 Ext. Clock connector on the rear panel of

the unit. Typically, the clock source on one side of the link is set to Internal,

and the other is set to Network. (Default - Smt: Int., Rcv: Net 1)

Secondary Clock Source This allows the user to select either the Secondary Clock Source, transmit

(xmt), and receive (rcv) for the individual T1 network ports.

To change the present Secondary Clock Source, use the up and down arrow

keys to highlight either Xmt or Rcv on the Secondary Clock Source line, and

use the Space Bar to toggle between the choices. For Xmt (transmit), the

choices are Network (NET), External (EXT), and Internal (INT). For Rcv, the

choices are Net-1 through Net 8 (each of the individual T1 network ports)

or Auto (the unit selects the best source) until the desired choice appears.

(Default - Xmt: Int, Rcv: Net2)

DSU Mode This allows the user to set the DL3800 up as a DSU, with one DTE, and one

Network port.

To change the present DSU Mode level, use the up and down arrow keys to

highlight the DSU Mode item, and use the Space Bar to toggle between the

following selections until the desired choice appears: Inverse MUX

(standard operation) or Single T1 DSU. Highlight Confirm, and press the

Enter key to conﬁrm the change. (Default-Inverse Mux)

Suppress Yellow Detect This item allows the user to conﬁgure the unit to ignore or report yellow

alarm conditions when in D4 framing.

To change the present Suppress Yellow Detect, use the up and down arrow

keys to highlight the item, and use the Space Bar to toggle between

Enabled and Disabled until the desired choice appears. Highlight

Confirm, and press the Enter key to conﬁrm the change. (Default -

Disabled)

Table 4-7 NETWORK CONFIGURATION MENU Options (Continued)

Parameter Description/Action