
CHF15.90
TP-Link Mc220l
TP-Link Mc220l
In the meantime, the answer has been found: you need a TL-SM321B SFP module opposite a TL-SM321A SFP module. One transmits on 1310nm and reads on 1550nm and the other transmits on 1550nm and reads on 1310nm.
So it's logical that if you put the same SFP module at both ends, it won't work!
Are the RJ45 patch cables or cross-over?