Patch 86241-06 For Rapier Switches

25

Diagnostic loopback is shown in Figure 3 on page 25. In this loopback mode the transmit signal is connected straight to the receive signal.

Figure 3: Diagnostic Loopback.

Far End

TX

RX

RX

TX

DS3 NSM

DS33

In C-bit parity mode it is also possible for the switch to request a loopback at the far end. This is shown in Figure 4 on page 25. This is achieved using the FEAC channel. The switch can also respond to remote loopback requests via the FEAC channel from the far end. This results in a near end Line Loopback (see above).

Figure 4: Remote Loopback.

Far End

TX

RX

RX

TX

DS3 NSM

DS34

Note that it is possible to configure near end local and remote loopbacks at the same time.

DS3 Configuration

The DS3 interface on the switch is automatically configured by the software modules when the switch sets up. Certain aspects of the DS3 signal can be altered to allow the switch to connect to another vendor’s equipment via the DS3 interface.

The configuration of the DS3 interface can be changed with the command:

SET DS3=instance [CLOCK={LOOPINTERNAL}] [CMTCE={ONOFF}] [DIRECTION={TRANSMITRECEIVE}] [EIC=equipment-id] [FAC=facility-id] [FDET={ONOFF}] [FIC=frame-id] [GENNO=generator-id][LIC=location-id] [PARAM15=threshold] [PARAM24=threshold] [PORT=port-id] [PRIM15=threshold] [PRIM24=threshold] [UNIT=unit-id] [TYPE=[{PIDISIDTSID}]

The CLOCK parameter specifies the clock source for the DS3 interface. The default is LOOP timing where the clock is derived from the received DS3 signal. If INTERNAL is selected the DS3 transmit signal is timed using an internal clock.

The CMTCE parameter specifies whether the terminal-to-terminal path-maintenance link is switched on. When CMTCE is set to OFF the maintenance link is switched off and the C-bits in M-subframe 5 are all set to one. If CMTCE is set to ON the maintenance link is switched on. The path

Patch 86241-05 for Software Release 2.4.1 C613-10340-00 REV E

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Allied Telesis 86241-06 manual DS3 Configuration