Avaya M770 - page 73

Chapter 5 Managing Physical Ports
Avaya M770 ATM Switch User’s Guide 53
Specifying loopback type for a DS3 port
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).
Note: 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.
Specifying the Tx Clock source for a DS3 port
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.