Asterisk Channel Variables
REDIRECTIONPN
Redirection Party Number
REDIRECTINGPN (see NOTE 1)
Redirecting Party Number
USERUSER_IA5 (see NOTE 1)
IA5 coded User-User signalling data
USERUSER_B64 (see NOTE 1)
Base64 coded User-User signalling data. Takes precedence over USERUSER_IA5.
USERUSER_PROTOCOL (see NOTE 1)
Protocol setting for User-User signalling data. Takes any integer value 0..255 according to ITU-T Q.931. If not set, value 4 “IA5 characters” is used as protocol setting.
TRANSFERCAPABILITY and CALLTYPE (see NOTE 2)
Bearer type on incoming calls
- Possible values: AUDIO, DIGITAL, RESTRICTED_DIGITAL, 31KAUDIO, 7KAUDIO, VIDEO, UNKNOWN
CALLINGSUB, CALLEDSUB (see NOTE 1)
Calling Party Subaddress, Called Party Subadddress see ITU-T Q.931 for more information
- Due to Asterisk’s channel variable restrictions, incoming data is truncated to a 0-terminated string.
CALLINGSUB_TYPE, CALLEDSUB_TYPE (see NOTE 1)
Parameter “Type” for CALLINGSUB / CALLEDSUB
- Possible values: NSAP, USER
- Default value: USER
CALLINGSUB_ODDEVEN, CALLEDSUB_ODDEVEN (see NOTE 1)
Parameter “Odd/Even” for CALLINGSUB / CALLEDSUB
- Possible values: ODD, EVEN
- Default value: EVEN
NOTE 1: This variable is also set automatically by an incoming call on a Srx-channel when the corresponding ISDN information element is present.
NOTE 2: This variable is only set on *incoming* calls (to Asterisk).For setting the bearer type, please use the SetTransferCapability” dialplan application.
Variables must be set *before* the new Srx-channel is created. Use the underscore “_” to make Asterisk copy the variable to the new channel.
Example:
exten => 1234,1,SetVar(_REDIRECTINGPN=5678) ; set variable to some value
exten => 1234,2,Dial(Srx/gMyGroup) ; call destination party
This will present a redirection with “redirecting party number” = 5678.
NOTICE:
Variables on the *calling* channel can also be updated after the channel is created. Updates are propagated each time an “indication” (like Progress, Alerting, …) is sent to the calling channel.
By this mechanism you can inform the calling party immediately when the call is being forwarded to a new destination by simply setting the REDIRECTIONPN channel variable *before* the new destination is being called.
exten => 1234,1,Dial(firstdestination|10) ; call first destination with timeout
exten => 1234,2,SetVar(_REDIRECTIONPN=newdestination) ; inform calling party
exten => 1234,3,SetVar(_REDIRECTINGPN=firstdestination) ; inform called party
exten => 1234,4,Dial(newdestination) ; call new destination
WARNING:
To *overwrite* a previously written variable starting with a “_”, you first have to clear the variable’s contents (without “_” !!).
exten => 1234,1,SetVar(_REDIRECTINGPN=5678) ; set variable to some value
exten => 1234,2,SetVar(REDIRECTINGPN=) ; clear variable again
exten => 1234,3,SetVar(_REDIRECTINGPN=0815) ; set variable to some other value
Further AOC related Channel Variables are described in AOC Engine.
See Also
Previous: Asterisk CLI commands
Next: AOC Engine
Index: Asterisk Sirrix ISDN channels
Phone System 