180 response is received and the voice channel is already
open (due to a previous 183 early media response or due
to an SDP in the current 180 response), the device
configured for ISDN / CAS doesn't play the ringback tone;
PI = 8 is sent in an ISDN Alert message (unless the
ProgressIndicator2ISDN_x parameter is configured
differently). If a 180 response is received, but the 'early
media' voice channel is not opened, the device configured
for CAS plays a ringback tone to the PSTN. The device
configured for ISDN operates according to the
LocalISDNRBSource parameter:
1) If LocalISDNRBSource is set to 1, the device plays a
ringback tone and sends an ISDN Alert with PI = 8 to the
ISDN (unless the ProgressIndicator2ISDN_x parameter is
configured differently).
2) If LocalISDNRBSource is set to 0, the device doesn't
play a ringback tone. No PI is sent in the ISDN Alert
message (unless the ProgressIndicator2ISDN_x
parameter is configured differently). In this case, the PBX /
PSTN plays a ringback tone to the originating terminal.
Note that the receipt of a 183 response results in an ISDN
Progress message (unless SIP183Behaviour is set to 1). If
SIP183Behaviour is set to 1 (183 is handled the same way
as a 180 + SDP), the device sends an Alert message with
PI = 8, without playing a ringback tone.
[3] Play Local Until Remote Media Arrive = Plays a ringback
tone according to received media. The behaviour is similar to
[2]. If a SIP 180 response is received and the voice channel is
already open (due to a previous 183 early media response or
due to an SDP in the current 180 response), the device plays
a local ringback tone if there are no prior received RTP
packets. The device stops playing the local ringback tone as
soon as it starts receiving RTP packets. At this stage, if the
device receives additional 18x responses, it does not resume
playing the local ringback tone. Note that for ISDN trunks, this
option is applicable only if the LocalISDNRBSource parameter
is set to 1.
Note: This parameter is applicable to the Gateway and IP-to-IP
applications.
Web: Play Ringback Tone to
Trunk
CLI: play-rbt-to-trk
[PlayRBTone2Trunk_x]
Determines the playing method of the ringback tone to the trunk
side, per trunk.
[-1] Not configured = (Default) The settings of the
PlayRBTone2Tel parameter is used.