Paradyne COMSPHERE 3610 - Remote Digital Loopback; Bilateral Loopback

Front Panel Operation
3-113610-A2-GB46-60 December 1996
Remote Digital Loopback
Remote Digital Loopback (RL ) supports testing by an
external device, such as a protocol analyzer connected to
the local DSU’s DTE interface. Data input is sent to the
remote DSU and returned for error detection.
In Remote Digital Loopback, the local DSU (control or
tributary) puts the remote DSU into Digital Loopback. A
control DSU can originate Remote Digital Loopback on a
point-to-point or multipoint network. A tributary DSU can
originate Remote Digital Loopback in a point-to-point
network only
. RL does not appear when in Remote mode.
Remote Digital Loopback can also be initiated by
receiving a V.54 pattern that starts a Digital Loopback.
For point-to-point configurations, enable configuration
options V .54 Lpbk (V.54 Loopback – Table 4-1) and
RespondRDL (Respond to Remote Digital Loopback –
Table 4-4).
The control DSU can send a Digital Loopback to a
multipoint tributary and perform a Remote Digital
Loopback on the multipoint tributary. A Digital Loopback
cannot be initiated from a multipoint tributary.
When a DSU (control or tributary) originates Remote
Digital Loopback, both the originating DSU and the
targeted DSU enter T
est mode. No other test can be run at
the originating DSU or the tar geted DSU until the Remote
Digital Loopback is aborted.
Bilateral Loopback
Bilateral Loopback combines Digital (DL) and DTE
loopbacks and operates simultaneously in the same DSU.
For point-to-point configurations, use the Bilateral
Loopback (Bilat Lpbk) configuration option from the
General (Gen) configuration option set (Table 4-4).
Once the loopback test begins, the message Command
Complete appears. If the Bilateral Loopback
configuration option is activated, requesting a Remote
Digital Loopback (RL) or Digital Test (DT) automatically
initiates a DTE Loopback. A Digital Test (DT) starts a
Remote Loopback which causes a Bilateral Loopback at a
remote site.
496-14493-0
2
Control
DSU
DTE
DTE
LL
COMSPHERE 3610
DTE
NETWORK
RL on
Aggregate
RL on a
Port
COMSPHERE 3610
Tributary
DSU
Figure 3-3. Loopbacks, Example 1
496-14762-0
1
Control
DSU
DTE
DL on a
Port
DL on
Aggregate
RL
DTE
COMSPHERE 3610 COMSPHERE 3610
DTE
Bilateral
Loopback
NETWORK
Tributary
DSU
Figure 3-4. Loopbacks, Example 2