Alloy Computer Products POE120 Series Link Failure Propagation, Normal Status via a pair of LFP’s

6. Link Failure Propagation

The POE120 Series media converters support Link Failure Propagation (LFP). If the Copper port is unplugged, the converter stops transmission on the fibre port. This causes the remote fibre node link to fail as well. The LED’s on the converter will now show link failure on both the copper and fibre ports. If the fibre link fails, the converter restarts auto-negotiation on the copper port but always stays in the link failure state. This causes the remote copper node link to fail as well. The LED’s on the converter will now show link failure on both the copper and fibre ports.

Refer to Fig. 7 shown below for the normal status when link is active. Also refer to Fig. 8 and Fig. 9 for the LED status when copper Cable A, Fibre Cable B or Fibre Cable C fails.

Note:

The Link Failure Propagation (LFP) function only takes effect when S1-Bit4 (see Fig. 11) is enabled. When S1-Bit4 is disabled the media converter will function normally.

10/100 Switch

TP

●

			10/100		Remote
				Switch	Station
	B		A
LFP	C	LFP	TP
● ● Fibre Cable ● ●				●	●

Fig. 7 Normal Status via a pair of LFP’s

10/100					10/100	Remote
						Station
Switch	LFP	B	LFP	A	Switch
TP		C		TP
○	○ ○ Fibre Cable● ○				○	●

Fig. 8 The Status when Copper Cable A link is broken

10/100				10/100	Remote
					Station
Switch	LFP	B	A	Switch
		LFP
TP		C	TP
○	○ ○ Fibre Cable○ ○			○	●

Fig. 9 The Status when Fibre Cable C or B link is broken

Note : ● indicates LNK/ACT LED Lit

○indicates LNK/ACT LED Off