Verilink AS56/56Plus (896-502588-001) Product Manual - Manual (Page 60)

Testing the Access System 56
4-6 AS56 and AS56 Plus User Manual
Line Loop LLB causes a local line loop (at the Acce ss System56 unit where the
command was entered). RLB causes a remote line loop (at the distant end
of a point-to-point circuit); RLB should not be attempted in an Integrated
Access, Fractional T1 environment.
The CSU is excluded from the test path in a Line Loop configuration.
In a point-to-point circuit, the LLB and RLB are useful for looping back
any testing initiated by the other end, such as Payload BERT, Serial Port
BERT, or any externally generated testing.
In an Integrated Access, Fractional T1 circuit, LLB is useful for looping
back Serial Port testing initiated by any remote location.
WHEN TESTING IS COMPLETED, BE SURE TO TURN THE LOOP
“OFF”.
SELECT as required to turn the loop Off/On.
Diagnostics
_Ntwk Port
From Diag. Menu,
UP/DOWN to
display:
NI Diagnostics
NI LLB...:_On
SELEC , then
DOWN as required
to display:
NI Diagnostics
NI RLB...:_On
OR
1.536 Mbps 1.544 Mbps
Line Loop ON
Payload Networ
Interface
To
DTE