Interwork Connected Number between SIP and ISUP

 

 

The Connected Number parameter is an ISUP parameter found in either the ANM or CON messages. It is used to implement the Connected Line Identification Presentation (COLP) supplementary service. The Connected Number parameter is sent in the backward direction to identify the number that is connected to a call. Because of potential changes in a call such as call redirection and call transfers, the connected number parameter may be different than the called party number. This feature interworks the connected number parameter between the ISUP and SIP protocols and is only supported for ITU ISUP. Refer to the Call Flows below. 

Call Flow Diagrams

SIP to ISUP (ANM)

In the SIP to ISUP call scenario displayed below, if the ANM message received from the ISUP side includes the Connected Number parameter, the Connected Number parameter will be interworked and added to a new header generated by the IMG 2020. The new header will be added to the outgoing 200 OK message and will use the X-DLGCConnectedInfo custom SIP header format displayed in the Additional Information section below.

The Optional Forward Call Indicator (Optional FCI) is used to request that the ISUP side send the Connected Number parameter in its ANM.

SIP to ISUP (CON)

In the SIP to ISUP call scenario displayed below, if the CON message received from the ISUP side includes the Connected Number parameter, the Connected Number parameter will be interworked and added to a new header generated by the IMG 2020. The new header will be added to the outgoing 200 OK message and will use the X-DLGCConnectedInfo custom SIP header format displayed in the Additional Information section below.

The Optional Forward Call Indicator (Optional FCI) is used to request that the ISUP side send the Connected Number parameter in its CON.

ISUP to SIP (ANM)

In the ISUP to SIP call scenario displayed below, if the IMG 2020 receives a 200 OK message from the SIP side that includes the X-DLGCConnectedInfo parameter, the Connected Number parameter will be interworked and added to the outgoing ANM message.

ISUP to SIP (CON)

In the ISUP to SIP call scenario displayed below, if the IMG 2020 receives a 200 OK message from the SIP side that includes the X-DLGCConnectedInfo parameter, the Connected Number parameter will be interworked and added to the outgoing CON message.

 

Configuration

Below are instructions on how to configure the IMG 2020 to interwork the Connected Number parameter between SIP and ISUP. Before configuring, the IMG 2020 must have an initial configuration created on it. Refer to the Basic Configurations procedure and verify the basic functionality has been configured. Also, since the feature uses interworking between the SIP and ISUP protocol, verify that ISUP signaling and ISUP channel groups have been configured. Refer to the Configure SS7 topic for information on configuring SS7 ISUP.

Enable Mapping of ISUP Connected Number to SIP (Connected Line Identification Presentation)

A SIP Profile is needed to enable this feature and also to use the new X-Dialogic Connected Info private SIP header. Refer to SIP Profile - SGP topic for creating a SIP profile.

  • Right click on the SIP Profile object created and select New SIP Headers. In the SIP Headers object that appears, enable the X-Dialogic Connected Info field. See screen capture below. Refer to SIP Profile - Headers topic for more information.

 

Additional Information

  • A new custom SIP header was created for the SIP leg. The header is displayed below:

X-DLGCConnectedInfo: <sip:445019941@10.10.10.10>; noa=3; npi=1; pi=0; sci=1

  • If the X-DLGCConnectedInfo header does not include the noa (nature of address), npi (numbering plan indicator), pi (presentation indicator), or sci (screening indicator) the default values displayed below will be set for the ANM/CON Connected number and sent back to ISUP.

Parameter

Default Value

Nature of Address Indicator

"Unknown" (2)

Screening Indicator

"Network Provided" (3)

Address Presentation Restricted Indicator

"Presentation Allowed" (0)

Numbering Plan Indicator

"ISDN Numbering Plan" (1)

  • If the X-DLGCConnectedInfo Header contains non-numeric data as displayed below:

X-DLGCConnectedInfo: <sip:xyz1234abcdef@10.10.10.10>; noa=3; npi=1; pi=0; sci=1

The xyz will be dropped when the ANM/CON is sent.

  • In a SIP to ISUP call scenario with the feature enabled, if the IMG 2020 receives an ANM or CON message without address signals (any number) in the Connected Number Parameter, the IMG 2020 will not generate and send the X-DialogicConnectedInfo header to the SIP leg.

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