User guide

5-8 Solo E1 DSU User Guide—June 1998
5
It loops the payload data received from the E1 network back toward the
network. Before it is looped back, the data is regenerated and a new
framing pattern is inserted. Thus, the proper E1 framing of the DSU/CSU
and network can be veriÞed.
Figure 5-4 Loop Payload Test
The individual channel loop payload loops a selected ÒfractionÓ of the E1
signal toward the network. In this mode, the selected data is corrected for
BPV, CRC and framing errors, and the IBC is regenerated before the data is
looped back to the network.
Receive and transmit clocks and data are suppressed toward the V.35 port
on the DTE channels.
The DTE/NET Test
The loop DTE/NET test combines the loop DTE on full bandwidth, and the
loop NET tests.
Running Multiple Payload Tests
To run multiple loopbacks, the device must have more than two DTE ports.
You can run multiple loop payload tests simultaneously from Menu-9 or
SNMP, but not from the front panel interface.
You can run multiple fractional loop payload tests by sending fractional
loop codes from the remote DSU/CSU via SNMP, DLMS, a terminal, or
from the front panel interface.
CSU
Local Solo E1
GR618
DTE
Network
Interface
Network
Interface
CSUDSU
DSU
Remote Solo E1
Data
Port
Data
Port