Black Box LRU4240 - Manual (Page 79)

Dual Trunk E1 Router
Dual Trunk E1 Router User’s Guide TECHNICAL: 0118 96 56 000 67
Figure 8-1 Loop NET Test
Loop Payload Test
The Loop Payload test verifies proper operation of the unit and the network.
This test loops the payload data received from the 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 Dual Trunk E1 Router and network can be verified.
This test can loop Net1, Net2, and All Nets.
Loop Up Remote and Loop Down Remote Tests
The Loop Up/Down Remote test, illustrated in Figure 8-2 on page 8-68 , places the remote unit into
Network Loopback using the industry standard set codes. Once in Network Loopback, test patterns
can be sent to verify the Bit Error Rate (BER) performance of the bi-directional E1 network signal.
To place the remote unit into network loopback, the local Dual Trunk E1 Router continuously
transmits the industry standard loop up code to the remote unit. If the remote unit does not go into
network loopback within 15 seconds a failure is declared and the Dual Trunk E1 Router stops
sending the loop up code.
The loop code and network parameters for the local and remote units must match.
Use the Loop Down Remote test to terminate the remote loopback. This test can be used no matter
how the remote unit was put into loopback.
Perform the Loop Up Remote and Loop Down Remote tests from the front panel , user interface or
SNMP.
This test can loop Net1 and Net2, but not All Nets.
DSU CSU
Network
Interface
Network
Interface
WAN
Data
Port
LOCAL
Dual Trunk E1 Router
REMOTE
Dual Trunk E1 Router
CSU DSU
E1
E1