برخی از متغییر های سیستمی پر کاربرد:
${CDR(accountcode)} * - Account code (if specified)
${BLINDTRANSFER} - The name of the channel on the other side of a blind transfer
${BRIDGEPEER} - Bridged peer
${BRIDGEPVTCALLID} - Bridged peer PVT call ID (SIP Call ID if a SIP call)${CALLERID(ani)} * - Caller ANI (PRI channels)
${CALLERID(ani2)} * - ANI2 (Info digits) also called Originating line information or OLI
${CALLERID(all)} * - Caller ID
${CALLERID(dnid)} * - Dialed Number Identifier
${CALLERID(name)} * - Caller ID Name only
${CALLERID(num)} * - Caller ID Number only
${CALLERID(rdnis)} * - Redirected Dial Number ID Service
${CALLINGANI2} * - Caller ANI2 (PRI channels)
${CALLINGPRES} * - Caller ID presentation for incoming calls (PRI channels)
${CALLINGTNS} * - Transit Network Selector (PRI channels)
${CALLINGTON} * - Caller Type of Number (PRI channels)
${CHANNEL} * - Current channel name
${CONTEXT} * - Current context
${DATETIME} * - Current date time in the format: DDMMYYYY-HH:MM:SS (Deprecated;use ${STRFTIME(${EPOCH},,%d%m%Y-%H:%M:%S)})
${DB_RESULT} - Result value of DB_EXISTS() dial plan function
${EPOCH} * - Current unix style epoch
${EXTEN} * - Current extension
${ENV(VAR)} - Environmental variable VAR
${GOTO_ON_BLINDXFR} - Transfer to the specified context/extension/priority after a blindtransfer
${HANGUPCAUSE} * - Asterisk cause of hangup (inbound/outbound)
${HINT} * - Channel hints for this extension
${HINTNAME} * - Suggested Caller*ID name for this extension
${INVALID_EXTEN} - The invalid called extension (used in the "i" extension)
${LANGUAGE} * - Current language (Deprecated; use ${LANGUAGE()})
${LEN(VAR)} - String length of VAR (integer)
${PRIORITY} * - Current priority in the dialplan
${PRIREDIRECTREASON} - Reason for redirect on PRI, if a call was directed
${TIMESTAMP} * - Current date time in the format: YYYYMMDD-HHMMSS (Deprecated; use ${STRFTIME(${EPOCH},,%Y%m%d-%H%M%S)})
${TRANSFER_CONTEXT} - Context for transferred calls
${FORWARD_CONTEXT} - Context for forwarded calls
${DYNAMIC_PEERNAME} - The name of the channel on the other side when a dynamic feature is used.
${DYNAMIC_FEATURENAME} The name of the last triggered dynamic feature.
${UNIQUEID} * - Current call unique identifier
${SYSTEMNAME} * - value of the systemname option of asterisk.conf
${ENTITYID} * - Global Entity ID set automatically, or from asterisk.conf