"EF" Version

Your modem is an EF model version if any of the following requirements are met:

• Modem serial number contains 59658F (e.g., xxxx-59658F-xxxx)
  
• Box Item # includes EF [e.g., 15530-xx-xxEF]
  
• Phone and Modem Options (or Modems) control panel information includes “SoftRing”

"D" or "DF" Version

Your modem is a D or DF model version if any of the following requirements are met:

• Modem serial number contains 59655 [e.g., xxxx-59655-xxxx]
• Box Item # includes D or DF [e.g., 15530-xx-xxD(F)]
• Phone and Modem Options (or Modems) control panel information includes “Smart Link”

“A”, “B”, “C” or Earlier Version

Your modem is an A, B, C or earlier model version if any of the following requirements are met:

• Box Item # number includes A, B, C, or no letter [e.g., 15530-xx-xx(A/B/C)]
• Modem card has a Conexant chip
• Phone and Modem Options (or Modems) control panel information includes “CNXT”