AudioCodes E-SBC

CHAPTER23 Digital PSTN
Mediant 1000 Gateway & E-SBC | User's Manual
Parameter Description
'Play Ringback Tone to
Trunk'
configure voip >
interface e1-t1|bri >
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.
■ [0] Don't Play = When the device is configured for ISDN
or CAS , it doesn't play a ringback tone. No Progress
Indicator (PI) is sent to the ISDN unless the
[ProgressIndicator2ISDN_x] parameter is configured
differently.
■ [1] Play on Local =
When the device is configured for CAS, it plays a local ring-
back tone to the PSTN upon receipt of a SIP 180 Ringing
response (with or without SDP). Note that the receipt of a
SIP 183 response does not cause the device configured
for CAS to play a ringback tone (unless the SIP183Be-
haviour parameter is set to 1).
When the device is configured for ISDN, it operates
according to the LocalISDNRBSource parameter, as fol-
lows:
✔ If the device receives a SIP 180 Ringing response
(with or 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).
✔ 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 to play a ringback
tone; the device sends 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 = 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 or 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. If a 180 response is
received, but the 'early media' voice channel is not
opened, the device configured for ISDN operates
according to the LocalISDNRBSource parameter:
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