I am new to cable internet. My provider gave me a box during installation but didin't use it - just connected the modem through USB to PC. Box' label says SMC-GT1255FTX-SC. Looked online - appears to be a 10/100 PCI Combo RJ45 and SC Network Adapter. Do I really need it? Connections seems fine - downloading at 100-350 kbs. Could it improve my connection if I use it? Do I need anything extra? Would that be worth buying? Thank you in advance.