CANOGA PERKINS 2461 E1 Modem - Manual (Page 49)

EdgeAccess Universal Chassis System
2461 Modem User Manual 5-7
5.4.5 Local Bi-Directional Loopback
When activated, the Local Bi-Directional Loopback test will cause all data transmission from the
local user device to be looped back toward the receive side of that same device. At the same time,
all data transmissions from the remote unit will be looped back towards the transmit side of the
same device (Figure 38).
Figure 38. Local Bi-Directional Loopback
5.4.6 Remote Bi-Directional Loopback
When activated, the Remote Bi-Directional Loopback test will cause all data transmission from
the local user device to be looped back after the data Decoder/Encoder functional block in the
remote modem. At the same time, the data transmissions from the remote user device will be
looped back towards the transmit side of the remote user (See Figure 39).
Figure 39. Remote Bi-Directional Loopback
Optical
Link
LIU
Rx
Logic LIU
Mux-
Enc
Demux-
Dec
Demux-
Dec
Mux-
Enc
Fiber Logic Fiber
Tx
Rx
Tx
Optical
Link
LIU
Rx
Logic LIU
Mux-
Enc
Demux-
Dec
Demux-
Dec
Mux-
Enc
Fiber Logic Fiber
Tx
Rx
Tx