Common channel interoffice signaling: Field implementation

This article reviews the Bell System domestic toll CCIS introduction plan and summarizes the early stages of this field implementation. Establishment of the first two signaling regions, installation and cutover of the first two new CCIS toll switching offices, and the first retrofit of CCIS to an existing office are each described. Emphasis is placed on discussion of the installation sequence and special test methods developed for adding the CCIS feature to in-service switching offices in an efficient and reliable manner.