Paradyne COMSPHERE
3610, Operator'S Manual

Page: 100 / 310

COMSPHERE 3600 Series Data Service Units
4-20 July 1999 3610-A2-GB91-90
Remote Digital Loopback
Remote Digital Loopback (RL) is typically used in
support of testing by an external device, such as a protocol
analyzer connected to the local DSU’s DTE interface. A
test message from the external device is looped back from
the receiver to the transmitter in the remote DSU and
returned to the local DSU (Figure 4-7).
NOTE
The Remote Digital Loopback
command is not available when
the LPDA-2 configuration option is
enabled.
In Remote Digital Loopback, the local DSU (control or
tributary) puts the remote DSU into Digital Loopback.
NOTE
A control DSU can originate a
Remote Digital Loopback in a
point-to-point or multipoint
network, whereas a tributary DSU
can originate a Remote Digital
Loopback in a point-to-point
network only.
For a DSU, Remote Digital Loopback is session-
disruptive except when a dial backup session is active. It
is used to determine whether a control DSU, a single
tributary, and the network between them are functioning
properly. This requires a network connection to both
DSUs. However, a DTE connection to the remote DSU is
not required.
In a point-to-point network only, Remote Digital
Loopback can also be initiated by the DTE by raising
Pin 21 of the EIA-232-D/V.24 interface or Pin N of the
V.35 interface, provided the Remote Digital Loopback by
DTE (RL by DTE) configuration option is enabled.
To access Remote Digital Loopback from the top-level
menu, make the following selections:
•
Local (F1)
•
Test
•
DSU (select active core)
•
Lpbk
•
RL
•
Port Select (when not operating in single-port
mode)
•
Trib Address (control DSU only)
Figure 4-7. Remote Digital Loopback