new old head

Wow things have changed, I remember you only needed to scan some macs in different nodes to get online. back then my modem of choice was the sb4100. I'm hearing now you need certs/serials ? How does one obtain or manufacture the certs? Im on OOL Brooklyn NY. oh and is the Motorola SB6120 Modem any good? I only remember the 4100 and DPC2100's