A number of call variables exist which can be used to perform tasks. For example, $NAM can be used to speak the user's name within an action's entry prompt. Call variables can also be checked using actions such as Variable Routing and Test Variable to branch the call flow according to the variables value.
Unless otherwise stated, call variables specific to a particular call on the voicemail server. They do not persist between calls, including calls transferred from voicemail server that then return. Also, unless otherwise stated the values are 'read-only'.
Variable Length: The length of the value stored within a variable is limited. The limit is 512 characters.
Write: This column indicates those call variables where the existing value can be changed using methods such as generic action commands. Other call variables have a fixed value set when the call is received by the voicemail server or, for$DBD values, the value is requested by the voicemail server.