Paradyne CSU User Manual
8. Troubleshooting
8-32
September
2002
9128-A2-GB20-80
Data Channel Loopbacks on a Frame Relay Link
A network-initiated Data Channel Loopback (DCLB) loops data over the frame
relay link (DS0s) received on the network interface through the FrameSaver unit’s
framing circuitry and back to the same interface.
relay link (DS0s) received on the network interface through the FrameSaver unit’s
framing circuitry and back to the same interface.
A DCLB can be controlled over the frame relay link using one of the following
in-band methods:
in-band methods:
V.54 Loopback.
ANSI T1.403 Annex B Fractional T1 ( FT1) Channel Loopback.
The frame relay service provider can use DCLB to verify the integrity of the frame
relay circuit.
relay circuit.
CAUTION:
V.54 and FT1 Loopbacks may affect operation of frame relay PVCs
assigned to the selected port. While in loopback, the frame relay link will
be down so any IP data being sent while this test is active will be
disrupted.
assigned to the selected port. While in loopback, the frame relay link will
be down so any IP data being sent while this test is active will be
disrupted.
Framer
Other
T1
Interface
DCLB
The T1
Interface
All
1s
1s
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