ADTRAN 6530 User Manual

Page 15

61225001L1-5D

Loopbacks may be initiated via the VT100 test
screens, front panel pushbuttons, Nx64K port control
leads, or by receiving V.54 or PN127 in-band looping
signals. Not all loopback types are available for all

ports and port services by all initiating sources. See
Table 9 for an overview. A key to the symbols
displayed in the Table 9 is available below the Table.

Table 9. Loopback Overview

Ports
Customer, away
from SHDSL Port (left)

Network, toward SHDSL
Port (right)

Services

Initiating Source

Nx64K Port

G.703 Port

SHDSL Port

G.704 Service

Nx64K Service

VT100 Test Screens

VT100 Loopback On
(Initiates one of five
loopback types,
regardless of the
associated Loopback
Type Option setting.)*

VT100 Loopback Off

LL Button On
(Initiates a Local
Customer Loopback per
the selected port Loopback
Type Option setting)

Single
service
only

LL Button Off

RL Button On
(Initiates a Remote
Network Loopback per
the remote unit’s selected
port Loopback Type
Option setting)*

RL Button Off

Nx64K Port Control Leads

C141 LL On
(Initiates a Local
Customer Loopback
per the Nx64K port
Loopback Type Option
setting)

C141 LL Off

C140 RL On
(Initiates a Remote
Network Loopback
per the remote unit
Nx64K port Loopback
Type Option setting)*

C140 RL Off

Receive In-band
Preparatory Signal
(Applies the loopback
after detection of
in-band V.54 or PN127
remote looping pattern
per the associated
service Loopback
Type Option setting)

N/A

Receive In-band
Termination Signal
(Terminates loopback
after detection of
in-band V.54 or PN127
remote looping pattern)

(Same as
Nx64K Service)

(Same as
Nx64K Port)

AIS

In-band Looping Protocol Reception

Key:

Dual Loop

AIS

Nontransparent Loop

Transparent Loop

No Loop

Sends
In-Band
Patterns

Sends
EOC
Request
Message

Sends
In-Band
Patterns

N/A

* The reception of in-band loopback patterns and EOC loopback request messages may be ignored or blocked on certain
SHDSL LTUs installed in Total Access 3000 Systems