Its initial products were Ringing ( telephony ) generators .
It also developed xDSL Remote Power Feeding Modules , before inventing Power over Ethernet 's ( PoE ) precursor Power over LAN .
Its initial products were Ringing ( telephony ) generators , and it also developed xDSL Remote Power Feeding Modules , before inventing Power over Ethernet 's ( PoE ) precursor Power over LAN .