AudioCodes Mediant 500 E-SBC User Manual page 833

User's Manual
Parameter
Web: Play Ringback Tone to
Version 6.8
without SDP) and the LocalISDNRBSource parameter is set
to 1, it plays a ringback tone and sends an ISDN Alert with
PI = 8 (unless the ProgressIndicator2ISDN_x parameter is
configured differently).
2) If the LocalISDNRBSource parameter is set to 0, the
device doesn't play a ringback tone and an Alert message
without PI is sent to the ISDN. In this case, the PBX / PSTN
plays the ringback tone to the originating terminal. Note that
the receipt of a 183 response does not cause the device
configured for ISDN to play a ringback tone; the device
issues a Progress message (unless SIP183Behaviour is set
to 1). If the SIP183Behaviour parameter is set to 1, the 183
response is handled the same way as a 180 Ringing
response.

[2] Prefer IP = (Default):

Digital Interfaces: Plays according to 'Early Media'. 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 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.
Determines the playing method of the ringback tone to the trunk
833
53. Configuration Parameters Reference
Description
Mediant 500 E-SBC