## chan_dahdi

    ${ANI2}               * The ANI2 Code provided by the network on the incoming call.
                            (ie, Code 29 identifies call as a Prison/Inmate Call)
    ${CALLTYPE}           * Type of call (Speech, Digital, etc)
    ${CALLEDTON}          * Type of number for incoming PRI extension
                            i.e. 0=unknown, 1=international, 2=domestic, 3=net_specific,
                            4=subscriber, 6=abbreviated, 7=reserved
    ${CALLINGSUBADDR}     * Caller's PRI Subaddress
    ${FAXEXTEN}           * The extension called before being redirected to "fax"
    ${PRIREDIRECTREASON}  * Reason for redirect, if a call was directed
    ${SMDI_VM_TYPE}       * When an call is received with an SMDI message, the 'type'
                            of message 'b' or 'u'