Asterisk func channel

Synopsis:

CHANNEL(item)

Description:

Gets/set various pieces of information about the channel. (New in 1.4)

item may be one of the following:

Read/write	Item	Description
R/O	audioreadformat	format currently being read
R/O	audionativeformat	format used natively for audio
R/O	audiowriteformat	format currently being written
R/W	callgroup	call groups for call pickup
R/O	channeltype	technology used for channel
R/W	language	language for sounds played
R/W	musicclass	class (from musiconhold.conf) for hold music
R/O	state	state for channel
R/W	tonezone	zone for indications played
R/O	videonativeformat	format used natively for video

Items available in 1.6:
Standard items (provided by all channel technologies) are:

Read/write	Item	Description
R/O	audioreadformat	format currently being read
R/O	audionativeformat	format used natively for audio
R/O	audiowriteformat	format currently being written
R/W	callgroup	call groups for call pickup
R/O	channeltype	technology used for channel
R/W	language	language for sounds played
R/W	musicclass	class (from musiconhold.conf) for hold music
R/W	parkinglot	parkinglot for parking
R/W	rxgain	set rxgain level on channel drivers that support it
R/O	state	state for channel
R/W	tonezone	zone for indications played
R/W	txgain	set txgain level on channel drivers that support it
R/O	videonativeformat	format used natively for video

chan_iax2 provides the following additional options:

Read/write	Item	Description
R/W	osptoken	Get or set the OSP token information for a call
R/O	peerip	Get the peer’s ip address
R/O	peername	Get the peer’s username

chan_sip provides the following additional options:

Read/write	Item	Description
R/O	peerip	Get the IP address of the peer
R/O	recvip	Get the source IP address of the peer
R/O	from	Get the URI from the From: header
R/O	uri	Get the URI from the Contact: header
R/O	useragent	Get the useragent
R/O	peername	Get the name of the peer
R/O	t38passthrough	1 if T38 is offered or enabled in this channel, otherwise 0
R/O	rtpqos *	Get QOS information about the RTP stream
R/O	rtpdest **	Get remote RTP destination information

*The option rtpqos takes two additional arguments:

Argument 1:
audio Get data about the audio stream
video Get data about the video stream
text Get data about the text stream
Argument 2:
local_ssrc Local SSRC (stream ID)
local_lostpackets Local lost packets
local_jitter Local calculated jitter
local_maxjitter Local calculated jitter (maximum)
local_minjitter Local calculated jitter (minimum)
local_normdevjitter Local calculated jitter (normal deviation)
local_stdevjitter Local calculated jitter (standard deviation)
local_count Number of received packets
remote_ssrc Remote SSRC (stream ID)
remote_lostpackets Remote lost packets
remote_jitter Remote reported jitter
remote_maxjitter Remote calculated jitter (maximum)
remote_minjitter Remote calculated jitter (minimum)
remote_normdevjitter Remote calculated jitter (normal deviation)
remote_stdevjitter Remote calculated jitter (standard deviation)
remote_count Number of transmitted packets
rtt Round trip time
maxrtt Round trip time (maximum)
minrtt Round trip time (minimum)
normdevrtt Round trip time (normal deviation)
stdevrtt Round trip time (standard deviation)
all All statistics (in a form suited to logging, but not for parsing)

**The option rtpdest takes one additional argument:

Argument 1:
audio Get audio destination
video Get video destination

Notes

Those items marked R/W above may be both read and set.
*CLI> show function CHANNEL
Additional items may be available from the channel driver providing the channel; see its documentation for details.
Any item requested that is not available on the current channel will return an empty string.

Return value

Returns the resulting string.

Example

exten => s,1,Set(foo=${CHANNEL(channeltype)})
exten => s,1,Set(CHANNEL(callgroup)=g3)