AudioCodes E-SBC User Manual page 470

CHAPTER 19 Coders and Profiles
Parameter
[IpProfile_EnableEarlyMedia]
'Early 183'
enable-early-183
[IpProfile_EnableEarly183]
Mediant 1000 Gateway & E-SBC | User's Manual
Description
■ [0] Disable (default)
■ [1] Enable
✔
Digital: The device sends a SIP 18x response with
SDP, allowing the media stream to be established
before the call is answered.
✔
Analog: The device sends a SIP 183 Session
Progress response with SDP instead of a 180
Ringing, allowing the media stream to be
established before the call is answered.
Note:
■ Digital: The inclusion of the SDP in the 18x response
depends on the ISDN Progress Indicator (PI). The SDP
is sent only if PI is set to 1 or 8 in the received
Proceeding, Alerting, or Progress messages. See also
the ProgressIndicator2IP parameter, which if set to 1 or
8, the device behaves as if it received the ISDN
messages with the PI.
✔
CAS: See the ProgressIndicator2IP parameter.
✔
ISDN: Sending a 183 response depends on the
ISDN PI. It is sent only if PI is set to 1 or 8 in the
received Proceeding or Alerting messages.
Sending 183 response also depends on the
[ReleaseIP2ISDNCallOnProgressWithCause]
parameter, which must be set to any value other
than 2.
■ See also the IgnoreAlertAfterEarlyMedia parameter.
The parameter allows, for example, to interwork Alert
with PI to SIP 183 with SDP instead of 180 with SDP.
■ You can also configure early SIP 183 response
immediately upon the receipt of an INVITE, using the
EnableEarly183 parameter.
■ Analog: To send a 183 response, you must also set the
[ProgressIndicator2IP] parameter to [1]. If set to [0], a
180 Ringing response is sent.
■ The corresponding global parameter is
[EnableEarlyMedia].
Enables the device to send SIP 183 responses with SDP
to the IP upon receipt of INVITE messages.
■ [0] Disable (default)
■ [1] Enable = By sending the 183 response, the device
opens an RTP channel before receiving the "progress"
tone from the ISDN side. The device sends RTP
packets immediately upon receipt of an ISDN
Progress, Alerting with Progress indicator, or Connect
message according to the initial negotiation without
sending the 183 response again, thereby saving
response time and avoiding early media clipping.
Note:
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