Serial RS-232 (console) Connections: 

RJ45 to DB25 or DB9 Adapters: 

Straight:  DBn (db9 & db25) to RJ45  Cross-Over DBn to DBn DBn to RJ45  Rollover:  DBn to DBn DBn to RJ45  Yost-DTE: DBn to RJ45  Yost-DCE:  DBn to RJ45

RJ45(m) to RJ45(m-f) Cables (or Dongles)

Straight:  RJ45(m) - RJ45(m)  Cross-Over RJ45(m) - RJ45(m)  Rollover:  RJ45(m) - RJ45(m) RJ45(m) - RJ45(f) (Panduit Mini-Com Tx)

RJ45(f) to RJ45(f) Adapters

Straight:  RJ45(f) - RJ45(f) (110-110)  Cross-Over RJ45(f) - RJ45(f) (110-110)  Rollover:  RJ45(f) - RJ45(f) (110-110)

Vendor Specific Serial Connectors

Ethernet (cat5) Connections: 

RJ45(m) to RJ45(m-f) Cables (or Dongles)

Straight:  RJ45(m) - RJ45(m)  Cross-Over RJ45(m) - RJ45(m)

RJ45(f) to RJ45(f) Adapters

Straight:  568B Cable (110-110)  Cross-Over 568B Cable (110-110)