Verilink PRISM 3111 (34-00242) Product Manual - Manual (Page 62)

54 C HAPTER 4: T ERMINAL I NTERFACE
The type of T1 loop is chosen by toggling the and is executed by
pressing .
Figure 4-6 Normal Operation
Net PLB (Payload Loopback) - The received network signal is looped back toward the
network with signal regeneration and framing and CRC regeneration. During the
NET PLB, AIS is transmitted out the T1 DTE and all ones are transmitted to the
DTE data port. The NET PLB may be activated by receipt of out of band loop
code on the network receive signal or by selection in the user interface
maintenance screen. Selections are None, LpUp and LpDn.
Far PLB You can activate a NET PLB on the remote end unit through this selection.The Net
PLB sends an out-of-band datalink message placing the far-end into a loop mode
per spec T1.403.
Net LLB (Line Loopback) - The received network signal is looped back toward the network
with signal regeneration only (framing and CRC intact). During the NET LLB,
AIS is transmitted out the T1 DTE while the network data is passed through to the
DTE data port. The NET LLB may be activated by receipt of inband or out of
band loop code on the network receive signal, by the front panel loop switch, or by
selection in the interface maintenance screen. Options include None, LpUp and
LpDn.
Network Interface Framer/Deframer
Framer/
Deframer
Multiplexor Receivers/Drivers
Receivers/
Drivers
BERT Generator/
Detector
From
Ports
To
NET
From
NET
To
Ports
From
NET
To
NET
DTE (DSX1)
(100' max.)
DTE Data Port
RJ-48C
RJ-48C
DSX1, 1'-655'
to cross-connect
1
2
4
5
4
5
1
2
To Network
From Network
Network Interface Framer/Deframer
Framer/
Deframer
Multiplexor Receivers/Drivers
Receivers/
Drivers
BERT Generator/
Detector
From
Ports
To
Net
From
NET
To
Ports
From
NET
To
NET
DTE (DSX1)
(100' max.)
DTE Data Port
RJ-48C
RJ-48C
DSX1, 1'-655'
to cross-connect
1
2
4
5
4
5
1
2
To Network
From Network NET
PLB
AIS
All Ones