This MIB module provides information for tracking the
progress and status of a data call from the hardware
layer through the application or service layer.
        
A data call is a call setup via a signaling
protocol (e.g., ISDN D Channel signaling) on the
Public Switching Telephony Network to a
Network Access Server in order to transfer data,
either as a byte stream (e.g., terminal emulation)
or in a packet format (e.g., PPP packets) from a
data terminal (e.g., Personal Computer) to a
data network (e.g., Internet).