This standard addresses the technical issues associated with Type 1, Type 2, and Type 2.5 Customer Premises Equipment for services such as Calling Identity Delivery, Visual Message Waiting Indicator, Calling Identity Delivery on Call Waiting and Call Waiting Deluxe. The Type 1 and Type 2 issues were previously addressed in TIA/EIA-716 and TIA/EIA-777 respectively. This document is intended to replace both TIA/EIA-716 and TIA/EIA-777. The services use On-Hook and Off-Hook signaling with data frames packaged in Single Data Message Format (SDMF), and Multiple Data Message Format (MDMF). Specifically, this standard establishes formal criteria for the signals and protocol that the CPE should be capable of receiving.

This standard is not in any way intended to be a guideline for switch suppliers or a Network Interface requirement