First Virtual Communications 065-7710 - Manual (Page 145)

Signamax
™
065-7710 8-Port 10/100BaseT/TX + 2SFP Managed Switch
Publication date: January, 2006
Revision A1
137
Function name:
Loopback Test
Function description:
In the Loopback Test function, there are two different loopback tests. One is
Internal Loopback Test and the other is External Loopback Test. The former
test function will not send the test signal outside the switch box. The test signal
only wraps around in the switch box. As to the latter test function, it will send
the test signal to its link partner. If you do not have them connected to active
network devices, i.e. the ports are link down, the switch will report the port
numbers failed. If they all are ok, it just shows OK.
Note: Whatever you choose Internal Loopback Test or External Loopback Test,
these two functions will interfere with the normal system working, and all
packets in sending and receiving also will stop temporarily.
Fig. 3-72