Clear-Com VOICE2 - Manual (Page 73)

Vitec Group Communications
VoICE IP Interface User Manual 4 - 3
VOICE WITH OTHER SYSTEMS
The VoICE unit can be used to intelligently link up to four 4-wire Audio
pairs or Asynchronous RS-422 data links between remotes sites using
Internet Protocol.
Figure 4-3: VoICE with Other Systems