What is "unistim"

UNIStim (or Unified Networks IP Stimulus) is a Telecommunications protocol developed by Nortel (now acquired by Avaya) for IP Phone (terminals and soft phones) and IP PBX communications.

Most manufacturers of IP PBX equipment ( Aastra, Alcatel, Avaya...) have followed the same path, developing their own proprietary protocols. These protocols are being gradually replaced or complemented by standardized protocols, including H.323, especially SIP.