The SIP REFER Method uses the Refer-To Header to pass contact information such as URI information which was provided in the initial request. The SIP Refer pane is used to enabled/disable the SIP REFER Call Transfer feature. The IMG has the ability to act as either a Transferee or a Transfer Target when used as part of the SIP Call Transfer functionality between three SIP UA’s. The IMG cannot become a Transferor. See field descriptions below for information on the fields within the SIP REFER Support object.

Use this pane to enabled/disable SIP REFER feature. The SIP REFER Support object was created in software revision 10.5.3. Prior to 10.5.3, the SIP Refer functionality was enabled through the SIP SGP object. Refer to the SIP Profile topic if running an earlier version of software than 10.5.3.


Accessing this Pane

Dialogic IMG EMS -> Profiles -> SIP SGP -> SIP Refer Support



Maximum Objects

1 per SIP SGP object


Related Topics

The SIP SGP Profile must be created first. Once created, the SIP REFER Support object can be created under it. The SIP SGP Profile object can then be linked to the SIP Signaling object, the External Gateway object, or ENUM Server Set object. Refer to the links in the Related Topics displayed below.

SIP Refer Call Transfer
SIP Profile
Delayed ANM SS7 to SIP


ClientView Pane: 10.5.3 CI


ClientView Pane 10.5.3 SP10


ClientView Pane 10.5.3 SP10.1


Field Descriptions

Refer Support

Disabled (default) - SIP Refer feature is disabled.

Enabled - SIP Refer is enabled. Contact information such as the URI INFO is passed in the Refer-To Header field.


From Header in Invite triggered by REFER

Caller A connects to caller B through IMG.

Referred-by header (default) - If Referred-By is selected, the From user on INVITE sent to Caller C due to REFER message sent, will use Referred-By user.

Original Caller - If Original Caller is selected, the From user on INVITE sent to Caller C will be Caller A if Caller B sent back REFER; the From user will be unavailable if Caller A sent back REFER.


Delayed Answer Support

Disabled (default) - The Delayed Answer Support is disabled. IMG will immediately send a connect message after receiving a 200 OK message.

Enabled - The Delayed Answer Support is enabled. When the Delayed Answer support is enabled the CONNECT or ANSWER message is not sent immediately. Instead the SIP device transfers the call to a new destination. When the transfer target answers, the ANSWER or CONNECT message is then sent back to the original PSTN caller.


Delayed Answer Timer (mins)

The Delayed Answer Timer field configures the number of minutes to wait before sending the CONNECT or ANSWER message. The Values range from 1 to 10 minutes and the timer is set by default to 1 minute when first enabled. To enable the Delayed Answer Timer field, the following fields need to be enabled first:



Release REFER Session

In 10.5.3 SP10.1 the Release REFER Session field was added. The Release REFER Session field gives the IMG the ability to release the SIP REFER session once the call has been transferred to the Redirected party. This functionality was added because in some older SIP Application servers, the Transferor (SIP Application Server) does not have the functionality to be able to release the SIP REFER session after the call has been transferred. The Release REFER Session field applies only when the IMG is the Transferee. For more information, refer to the SIP REFER Call Transfer topic.

Disabled (Default) - The IMG will not terminate the SIP REFER session once the call has been transferred. Termination or release of the SIP REFER session is left up to the Transferor (SIP Application). If the Transferor does not release the call, the IMG will eventually release the SIP REFER session when the call is terminated.

Enabled - As the Transferee, the IMG will release/terminate the SIP REFER session after the call has been redirected.