AudioCodes Mediant 3000 User Manual page 604

Parameter
Web/EMS: Enable Early
Media
[EnableEarlyMedia]
Web/EMS: Enable Early 183
[EnableEarly183]
[IgnoreAlertAfterEarlyMedi
a]
SIP User's Manual
Enables the device to send a 18x response with SDP instead of a
18x, allowing the media stream to be established prior to the
answering of the call.

[0] Disable = Early Media is disabled (default).

[1] Enable = Enables Early Media.
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 PRI 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.
Notes:

See also the IgnoreAlertAfterEarlyMedia parameter. This
parameter allows, for example, to interwork Alert + PI to SIP 183 +
SDP instead of 180 + SDP.

You can also configure early SIP 183 response immediately upon
receipt of an INVITE, using the EnableEarly183 parameter.

This parameter can be configured per IP Profile, using the
IPProfile parameter (see 'Configuring IP Profiles' on page 236) and
per Tel profile, using the TelProfile parameter (see 'Configuring Tel
Profiles' on page 233).
Enables the device to send SIP 183 responses with SDP to the IP
upon receipt of INVITE messages (for IP-to-Tel calls). The device
sends the RTP packets only once it receives an ISDN Progress,
Alerting with Progress indicator, or Connect message from the PSTN.

[0] Disable (default)

[1] Enable
For example, if enabled and the device receives an ISDN Progress
message, it starts sending RTP packets according to the initial
negotiation without sending the 183 response again. Therefore, this
feature reduces clipping of early media.
Notes:

To enable this feature, configure the EnableEarlyMedia parameter
to 1.

This feature is applicable only to ISDN interfaces.
Determines the device's interworking of Alerting messages from PRI
to SIP.

[0] = Disabled (default)

[1] = Enabled
When enabled, if the device sends a 183 response with an SDP (due
to a received ISDN Progress or Proceeding with PI messages) and an
Alerting message is then received from the Tel side (with or without
Progress Indicator), the device does not send an additional 18x
response, and the voice channel remains open. However, if the
device did not send a 183 with an SDP and it receives an Alert
without PI, the device sends a 180 (without SDP). If it receives an
Alert with PI it sends a 183with an SDP.
When disabled, the device sends additional 18x responses as a result
of receiving Alerting and Progress messages, regardless of whether
or not a 18x response was already sent.
Note: This parameter is applicable only if the EnableEarlyMedia
parameter is set to 1 (i.e., enabled).
604
Description
Document #: LTRT-89712
Mediant 3000