sipt Module

Torrey Searle

   Voxbone SA
   <torrey@voxbone.com>

   Copyright © 2013 Voxbone SA
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies
        3. Functions

              3.1. sipt_destination(destination, hops, nai)
              3.2. sipt_set_calling(origin, nai, presentation, screening)

        4. Exported pseudo-variables

              4.1. $sipt_presentation
              4.2. $sipt_screening
              4.3. $sipt_hop_counter
              4.4. $sipt_cpc
              4.5. $sipt_calling_party_nai
              4.6. $sipt_called_party_nai

   List of Tables

   1.1. Address Presentation Restricted Indicator Values
   1.2. Screening Indicator Values
   1.3. Calling Nature of Address Values
   1.4. Called Nature of Address Values

   List of Examples

   1.1. sipt_destination(destination, hops, nai) usage
   1.2. sipt_set_calling(origin, nai, presentation, screening) usage
   1.3. sipt_presentation pseudo-variable usage
   1.4. sipt_screening pseudo-variable usage
   1.5. sipt_hop_counter pseudo-variable usage
   1.6. sipt_cpc pseudo-variable usage
   1.7. sipt_calling_party_nai pseudo-variable usage
   1.8. sipt_called_party_nai pseudo-variable usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies
   3. Functions

        3.1. sipt_destination(destination, hops, nai)
        3.2. sipt_set_calling(origin, nai, presentation, screening)

   4. Exported pseudo-variables

        4.1. $sipt_presentation
        4.2. $sipt_screening
        4.3. $sipt_hop_counter
        4.4. $sipt_cpc
        4.5. $sipt_calling_party_nai
        4.6. $sipt_called_party_nai

1. Overview

   Module for updating ISUP encapuslated in SIP (SIP-T/SIP-I)

   The sipt module can be used to update various ss7 headers contained
   inside a message.

2. Dependencies

   The module depends on the following modules (in the other words the
   listed modules must be loaded before this module):
     * none

3. Functions

   3.1. sipt_destination(destination, hops, nai)
   3.2. sipt_set_calling(origin, nai, presentation, screening)

3.1. sipt_destination(destination, hops, nai)

   updates the IAM in the body if it exists, setting the called party
   number to “destination” with the nature address specified in “nai” and
   decrementing the hop counter value if present. If the hop counter
   header is missing it will be added with the value of “hops”.

   Example 1.1. sipt_destination(destination, hops, nai) usage
...
# update the destination number to our current request uri,
# setting nature of address to international
$rU = "19495551234";
sipt_destination($rU, 31, 4);
...

3.2. sipt_set_calling(origin, nai, presentation, screening)

   updates the IAM in the body if it exists, setting (or adding) the
   calling party number to “origin” with the nature address specified in
   “nai” and setting the presentation and screening values to
   “presentation” and “screening”.

   Example 1.2. sipt_set_calling(origin, nai, presentation, screening)
   usage
...
# update the calling party to the value in the from header
sipt_set_calling($fU, 4, 0, 3);
...

4. Exported pseudo-variables

   4.1. $sipt_presentation
   4.2. $sipt_screening
   4.3. $sipt_hop_counter
   4.4. $sipt_cpc
   4.5. $sipt_calling_party_nai
   4.6. $sipt_called_party_nai

4.1. $sipt_presentation

   Returns the value of the Address presentation restricted indicator
   contained in the Calling Party Number header of the IAM message if it
   exists. Returns -1 if there isn't a Calling Party Number header.

   Table 1.1. Address Presentation Restricted Indicator Values
   0 presentation allowed
   1 presentation restricted
   2 address not avail (national use)
   3 spare

   Example 1.3. sipt_presentation pseudo-variable usage
...
# add privacy header if restriction is requested
if($sipt_presentation == 1)
{
        append_hf("Privacy: id\r\n");
        $fn = "Anonymous";
}

...

4.2. $sipt_screening

   Returns the value of the Screening Indicator contained in the Calling
   Party Number header of the IAM message if it exists. Returns -1 if
   there isn't a Calling Party Number header.

   Table 1.2. Screening Indicator Values
   0 Reserved (user provided, not verified)
   1 User Provided, Verified and Passed
   2 Reserved (user provided, verified and failed)
   3 Network provided

   Example 1.4. sipt_screening pseudo-variable usage
...

# remove P-Asserted-Identity header if the screening isn't verified
# or network provided
$avp(s:screening) = $sipt_screening;
if($avp(s:screening) != 1 && $avp(s:screening) != 3)
{
        remove_hf("P-Asserted-Id");
}

...

4.3. $sipt_hop_counter

   Returns the value of the Hop Counter for the IAM message if it exists.
   Returns -1 if there isn't a hop counter.

   Example 1.5. sipt_hop_counter pseudo-variable usage
...
# get the hop counter and update the Max-Forwards header if it exists
$avp(s:hop) = $sipt_hop_counter;
if($avp(s:hop) > 0)
{
        remove_hf("Max-Forwards");
        append_hf("Max-Forwards: $avp(s:hop)\r\n");
}

...

4.4. $sipt_cpc

   Returns the value of the Calling Party Category for the IAM message.
   Returns -1 if there is a parsing error.

   Example 1.6. sipt_cpc pseudo-variable usage
...
# get the Cpc code and set put it in a custom sip header
append_hf("X-CPC: $sipt_cpc\r\n");

...

4.5. $sipt_calling_party_nai

   Returns the value of the Nature of Address Indicator of the Calling
   Party for the IAM message. Returns -1 if there is a parsing error or if
   the Calling Party Number is not present.

   Table 1.3. Calling Nature of Address Values
   0 Spare
   1 Subscriber Number (national use)
   2 Unknown (national use)
   3 National (significant) number (national use)
   4 International use

   Example 1.7. sipt_calling_party_nai pseudo-variable usage
...
# get the Calling Nai and add country code if national
if($sipt_calling_party_nai == 3)
{
        $fU = "32" + "$fU";
}

...

4.6. $sipt_called_party_nai

   Returns the value of the Nature of Address Indicator of the Called
   Party for the IAM message. Returns -1 if there is a parsing error.

   Table 1.4. Called Nature of Address Values
   0 Spare
   1 Subscriber Number (national use)
   2 Unknown (national use)
   3 National (significant) number
   4 International use
   5 Network-specific number (national use)

   Example 1.8. sipt_called_party_nai pseudo-variable usage
...
# get the Called Nai and add country code if national
if($sipt_called_party_nai == 3)
{
        $rU = "32" + "$rU";
}

...
