IMG 1010 - Interwork Diversion and RPID - SIP to SS7 REL

Feature F-5307 Interworking Diversion and RPID Headers from SIP to SS7 REL gives a user the ability to control and direct SS7 calls through the use of a SIP Application. When configured, the feature interworks the Diversion and Remote-Party-Id (RPID) Headers received from the SIP 4xx-Request/Client Failure, 5xx-Server Failure, or 6xx-Global Failure responses into Redirection Information and Generic Number Information in the SS7 REL message. This feature is supported in the ETSI V2 Variant only. See links below for more information.

Call Flow Diagram:

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• The originating MSC A sends IAM message with Dialed Number.

• The SS7 message is interworked to SIP and routed to a SIP application.

• Upon reception of the INVITE message, the SIP Application rejects it with a Diversion and Remote Party ID (RPID) Header in the 4xx, 5xx, 6xx failure responses.

• The IMG interworks the Diversion Header from SIP into a Redirection Number in the SS7 REL message.

• The IMG also interworks the Remote Party ID from SIP into a Generic Number in the SS7 REL message.

• The originating MSC A re-issues the IAM to the Target MSC B using the Redirection Number from the REL message as the Dialed Number and the Generic Number as the Calling Party Number. 

Mapping of Headers:

When feature is enabled, IMG will map the Diversion Header in SIP failure response message (4xx, 5xx, 6xx) into the SS7 ISUP Redirection Number parameter in the REL message with the following parameter values.

The SIP Remote-Party-ID (RPID) is mapped to the Generic Number as follows

APRI is mapped as follows:

Screening Indicator is mapped as follows:

Configuration:

The SIP Diversion Header to Redirection Number interworking is enabled in the 'SIP Headers' object which is configured under the SIP SGP object. The Diversion Header Support field must be set to 'Diversion' for the interworking of the SIP Diversion Header to Redirection Number to function as described above.  

The SIP Remote Party ID header to Generic Number interworking is by default always enabled. Any incoming  sip 4xx, 5xx, or 6xx responses with the Remote Party ID Header embedded will be interworked into the Generic Number in outgoing REL message.

Verify the following entities are configured before proceeding:

•  IMG 1010 - Logical IMG

• IMG 1010 - Physical IMG

• IMG 1010 - Configuring T1 or E1 Bearer Profile - 10.5.x

• IMG 1010 - IP Bearer Profile

• IMG 1010 - IP Network (Interface)

• IMG 1010 - Configuring T1 or E1 Bearer Spans - 10.5.x

• IMG 1010 - VoIP Resource

Configure these initial objects before proceeding to the procedure below.

Create SIP Headers object and enable Diversion.

• Right click on Profiles object created earlier and select New SIP SGP. A SIP object will appear. Change the ID from the first field to something other than ID:0. ID:0 is the default SIP profile and the SIP isub encoding field cannot be configured within this default object. See for more information on configuring this object.

• Right click on the SIP SGP object just created and select New SIP Headers. A SIP Headers object will appear. Select 'Diversion' from Diversion Header Support field drop down menu. See below:
  
  

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Create an External Network Element

Create an external gateway through the external network element object. This will be the gateway that the IMG will communicate with.

• Right click on Dialogic IMG EMS and select New External Network Elements. An External Network Elements pane will appear. No configuration is accomplished in this pane. This pane is a placeholder for multiple Network Elements to be created beneath it. See IMG 1010 - External Network Elements for more information.

• Right Click on External Network Elements object created and select New External Gateways. An External Gateways pane will appear. again this pane is a placeholder from multiple External Gateways. No configuration is needed. See IMG 1010 - External Gateways for more information.

• Right Click on the External Gateways object and select New External Gateway. A screen like below will appear:
  
  

  • Enter a name to identify the gateway that IMG will communicate with. This is the gateway that has SIP application set up to reject incoming INVITE with Diversion and Remote-Part-ID Headers.

  • Select SIP under the Gateway Signaling Protocol field- Enter IP Address of the Gateway the IMG will communicate with

  • Select the SIP SGP Profile that was created earlier. This profile has the SIP Headers object configured under it with Diversion Header Support set to 'Diversion'.  

• At this point the SIP to SS7 interworking of the Diversion and the RPID headers is configured on the IMG. 

The next step will be to set up the routing so that the specific channel groups are configured to route to the External Network element configured above. See any of the multiple topics that describe the routing process. The following two links below are a good starting point.

IMG 1010 - Overview of Routing

IMG 1010 - Configuring Routing

Additional Information:

• The feature is supported in the ETSI V2 variant only.

• Interworking for Diversion Header to Redirection Number is enabled by selecting Diversion from drop down menu in the SIP Headers Support field located in the SIP Headers object. See IMG 1010 - SIP Headers

• Interworking for Diversion Header to Redirection Number is disabled if either Disable, CC-Diversion, or History-Info is selected in the Diversion Header Support field.

• Interworking for Remote Party ID Header to Generic Number by default is always enabled.