Comment VxWorks (Score 1) 354
Nortel Networks is most likely the largest manufacturer of telephony equipment, both TDM and VoIP. All of their PBXs, all of their key systems, and almost all of their VoIP systems run on VxWorks. Its laughable that some VoIP vendors claim five 9s of reliability on a platform with an OS as unreliable as Windows. Nobody should seriously consider an enterprise telephony platform built on Windows.
