AudioCodes Mediant 600 User Manual page 664

Parameter
Web/EMS: PRACK Mode
[PrackMode]
Web/EMS: Enable Early
Media
[EnableEarlyMedia]
User's Manual
BYE sip:302@10.33.4.125 SIP/2.0
Via: SIP/2.0/UDP
10.33.4.126;branch=z9hG4bKac2127550866
Max-Forwards: 70
From:
<sip:401@10.33.4.126;user=phone>;tag=1c2113553324
To: <sip:302@company.com>;tag=1c991751121
Call-ID: 991750671245200001912@10.33.4.125
CSeq: 1 BYE
X-RTP-Stat:
PS=207;OS=49680;;PR=314;OR=50240;PL=0;JI=600;LA=40;
Supported: em,timer,replaces,path,resource-priority
Allow:
REGISTER,OPTIONS,INVITE,ACK,CANCEL,BYE,NOTIFY,PRACK
,REFER,INFO,SUBSCRIBE,UPDATE
User-Agent: Sip-Gateway-/v.6.2A.008.006
Reason: Q.850 ;cause=16 ;text="local"
Content-Length: 0
Determines the PRACK (Provisional Acknowledgment) mechanism
mode for SIP 1xx reliable responses.

[0] Disable

[1] Supported (default)

[2] Required
Notes:

The Supported and Required headers contain the '100rel' tag.

The device sends PRACK messages if 180/183 responses are
received with '100rel' in the Supported or Required headers.
Enables the Early Media feature.
Digital: 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.
Analog: Enables the device to send a 183 Session Progress response
with SDP instead of a 180 Ringing, allowing the media stream to be
established prior to the answering of the call.

[0] Disable (default)

[1] Enable
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 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.

For the CAS protocol: See the ProgressIndicator2IP parameter.

For the ISDN protocol: 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 PRI messages. Sending 183 response also
depends on the ReleaseIP2ISDNCallOnProgressWithCause
parameter, which must be set to any value except 2.
Notes:

See also the IgnoreAlertAfterEarlyMedia parameter. This parameter
allows, for example, to interwork Alert + PI to SIP 183 + SDP instead
of 180 + SDP.
664
Mediant 600 & Mediant 1000
Description
Document #: LTRT-83313