Avaya M770 Manuel D’Utilisation

Chapter 5

Managing Physical Ports

Avaya M770 ATM Switch User’s Guide

53

You can specify loopback type for a DS3 port.  Loopback is either line loopback 
(the receiver loops back the received line signal), or payload loopback (the receiver 
loops back the received payload), or none (no loopback). The default loopback is 
none (no loopback).

In order to start/stop loopback using the

 set loopback 

command both 

the Admin state and Oper state of the port must be UP.  Another method of 
stopping loopback is to disable the port. For more information about how to disable 
a physical port, see Disabling a Physical Port on page 49.

To set the loopback type for a DS3 port, use the

pport set

 

loopback

 command. 

You can specify the transmit clock source for a DS3 port.  The transmit clock source  
is either local (derives the clock internally), or loop (derives the clock from the 
received signal). The default setting is local.
To set the Tx clock source for a DS3 port, use the

pport set

 

txClock

 command.  

Command:

M4-DS3s8:/>pport set loopback <<slot>.<port>>[payload|line|none]

Example:

M4-DS3s8:/>pport set loopback 8.1 line

Parameters:

<pport id>

The physical port identifier in the form <slot>.<port.number>.

payload

Sets the loopback type to payload.

line

Sets the loopback type to line.

none

Sets the loopback type to none.

Command:

M4-DS3s8:/>pport set txClock <<slot>.<port>>[local|loop]

Example:

M4-DS3s8:/>pport set loopback 8.1 line

Parameters:

<pport id>

The physical port identifier in the form <slot>.<port.number>.

local

Sets the transmit clock source to local.

loop

Sets the transmit clock source to loop.