User`s guide

Diagnostics
6-5
5100-A2-GB20-00
November 1996
LAN Loopback
The LAN loopback enables data received from the CO card ISA bus to be looped
back by the Ethernet on-board transceiver. Note that this loopback interrupts data
transfer to the CP card. See
Diagnostics in Chapter 4 for the procedure to run a
loopback test.
496-1498
6
ISA
Bus
Ethernet
Transceiver
CO Card
Local Loopback
The local loopback enables data received from the CO ISA bus to be looped back
by the firmware process on the CO card. This will be a unidirectional loopback,
meaning that data is transmitted back to the PC end of the connection only. Note
that any data arriving over the DSL link is dropped in this mode of operation. See
Diagnostics in Chapter 4 for the procedure to run a loopback test.
496-1498
5
ISA
Bus
DSL
Link
CO Card