ISDN Headers

 

What are ISDN Headers?

ISDN headers are used to set message information & send via ISDN protocol.
NVG maps ISDN information elements into ISDN/SIP messages in order to pass specific ISDN parameters to the end user.

 

NVG uses ISDN headers to pass ISDN variables from ISDN->ISDN & ISDN->SIP (i.e. CIC, NADI, RDNIS..etc)

 


Passing information from ISDN->ISDN/ISDN->SIP

By default if NVG receives ISDN message with any of the ISDN-Headers defined below and the ISDN-Headers feature is enabled, NVG will automatically populate the associated ISDN messages with the specified values.  ISDN-Header will only be considered if it is properly formed, and matches the string found in the "ISDN-Header" column below, and is case-insensitive.

FreeSWITCH - How to Use ISDN Headers

ISDN->ISDN (Receiving ISDN Header From NSG) 

Unlike SS7 headers ISDN header will be stored in variable "Z" with Z being the ISDN header.
The example below will print to the log/console the value of the ISDN header that contains the the sub address type of calling party

Example:  <action application="log" data="The CID Sub Address Type Is: [${isdn.calling_subaddr_type}]"/>

SIP->ISDN (Sending ISDN Header To NSG)

You can populate an ISDN header by using the "export" application in FreeSWITCH.
The example below shows how to set the Calling party screen indicator value to 4.

Example:    <action application="export" data="isdn.cg_pty2.screen_ind=2"/>
 

NOTE: 

  1. ISDN-> ISDN means when parameters can be exported from ISDN to ISDN.

    ISDN->SIP means when parameters can be exported form ISDN to SIP .
    If "Y"  than that parameter can be set and exported/set. If "N" then it is not. 

 

Complete List of ISDN Headers
 

Calling/Connected Number Parameter

ISDN-Header

Description 

ISDN->ISDN

ISDN->SIP 

isdn.cg_pty2.screen_ind

Screen Indicator

Y

N

isdn.cg_pty2.presentation_ind

Presentation Indicator

Y

N

isdn.cg_pty2.npi

Numbering Plan Identification

Y

N

isdn.cg_pty2.ton

Type of Number

Y

N

isdn.cg_pty2.digits

Number Digits

Y

N


Calling/Connected Party Subaddress Parameters

ISDN-Header

Description 

ISDN->ISDN 

ISDN->SIP 

isdn.calling_subaddr_addr_url

Subaddress Information

Y

Y

isdn.calling_subaddr_oe_ind

Odd/Even Indicator

Y

Y

isdn.calling_subaddr_type

Type of Subaddress

Y

Y

 

Called Party Subaddress Parameters

ISDN-Header

Description 

ISDN->ISDN 

ISDN->SIP 

isdn.called_subaddr_addr_url

Subaddress Information

Y

Y

isdn.called_subaddr_oe_ind

Odd/Even Indicator

Y

Y

isdn.called_subaddr_type

Type of Subaddress

Y

Y

 

User to User Parameter

ISDN-Header

Description 

ISDN->ISDN 

ISDN->SIP 

isdn.user-user

User Information

Y

Y

isdn.user-user-pd

Protocol Discriminator

Y

N

 

Progress Indicator Parameter

ISDN-Header

Description 

ISDN->ISDN 

ISDN->SIP 

isdn.prog_ind.descr

Description

Y

N

isdn.prog_ind.loc

Location

Y

N

 

Network Specific Facility Parameters

ISDN-Header

Description 

ISDN->ISDN 

ISDN->SIP 

isdn.netFac.spec

Network Specific Facility Specification

Y

N

isdn.netFac.type

Type of network identification

Y

N

isdn.netFac.plan

Network Identification Plan

Y

N

 

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