IMG 1010 - ISUB Encoding ISDN - SIP

The ISDN calling party subaddress parameters convey address information of each device in ISDN network. The ISDN Calling Party subaddress can now be interworked into the SIP protocol using the isub and isub encoding parameters. By interworking these two parameters, the ISDN calling Party Subaddresses as well as its encoding type can be passed between ISDN and SIP as well as SIP and ISDN. Below is more information pertaining to the interworking of these parameters.

The interworking of the Calling Party subaddress was introduced in software 10.5.3_ER1. Starting in software version 10.5.3 SP4 the ISDN Called Party subaddress information will also be interworked between the SIP and ISDN protocols. Refer to the Call Flow diagrams below.

Call Flow Diagrams:

SIP to ISDN (Calling Party)

Open

ISDN to SIP (Calling Party)

Open

SIP to ISDN (Called Party)

ISDN to SIP (Called Party)

Mapping to ISDN Calling/Called Party Subaddress

*N/A - ISDN will not send calling party address.

isub-encoding value:

nsap-ia5- Indication that the “isub” parameter value needs to be encoded using IA5 (AFI = 0x50) when translated to an ISUP message

nsap-bcd- Indication that the “isub” parameter value needs to be encoded using Binary Coded Decimal (BCD) (AFI=0x48)

nsap- Indication that the “isub” parameter value needs to be encoded using the encoding type defined in ISO 8328  other than IA5 (AFI = 0x50) or BCD (AFI=0x48).

Mapping of ISDN Calling/Called Party Subaddress

**N/A - Outgoing SIP will not include 'isub' and 'isub encoding' parameters.

Call Trace:

Call Trace - ISUB ENC ISDN to SIP

Call Trace - ISUB ENC SIP to ISDN

Configuration:

The isub encoding parameter is a field added to the SIP From Header Tags object. The From Header Tags object is configured under the SIP SGP object and is eventually inserted into a external network element object. Below are instructions on how to configure the isub encoding parameter for interworking between ISDN and SIP. 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 SGP

When configuring the IMG to interwork the Calling and Called Party Subaddresses the configuration of the SIP SGP object differs when configuring the Called Party Subaddress as opposed to the Calling Party Subaddress. The next two sections below describe the process for each subaddress.

Create SIP Profile (SGP) and Enable ISUB Encoding (Calling Party)

• 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 IMG 1010 - SIP Profile - 10.5.3 for more information on configuring this object.

• Right click on the SIP SGP object just created and select New SIP from Header Tags. A SIP From Header Tags object will appear. Select 'enable' from the drop down menu. See below.
  
  

Create SIP Profile (SGP) and Enable ISUB Encoding (Called Party)

• 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 IMG 1010 - SIP Profile - 10.5.3 for more information on configuring this object.

• Click in the R-URI Header Tags field and a Select Multiple Items box will appear. Select ISUB Encoding from the list and select OK. See screen capture below.
  
  

The ISUB encoding field will now be populated with the isub/isub-encoding selection.

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 object 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 using ISUB Encoding
  - 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 ISUB Encoding configured in it.  

• At this point the Isub Encoding interworking 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 from ISDN 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:

• Calling Party Address- The parameters mapping is accomplished between SIP From Header isub/isub-encoding and the ISDN Calling Party Subaddress IE.

• Called Party Address- The parameters mapping is accomplished between R-URI and SIP To Header isub/isub-encoding and the ISDN Called Party Subaddress IE.