Configuring Lawful Interception

Applies to version(s): v2.7

Lawful Interception is configure by the following steps:

1. Configuring a Law Enforcement Agency and it's parameters
2. Creating a NAP that is connected to the Law Enforcement Agency
3. Providing a list of targets to intercept (through a coma-separate-values .csv file)
4. Enabling the Lawful Intercept routing script filter
5. Exchanging SSH public/private keys with server to allow password-less SFTP

To configure a Law Enforcement Agency and it's parameters

1- Select Lawful Interception from the navigation panel

This page contains global Lawful Intercept parameters, and a list of Law Enforcement Agencies.

Available parameter are:

• NWO (Network Operator) Identifier: An internationally unique identifier that represents the network operator, access provider or service provider using the Tmedia equipment

Law Enforcement Agency parameters

Multiple Law Enforcement Agencies can be created in Toolpack. Each operates independently of others, and can intercept the same calls, as well as different ones.

Each Law Enforcement Agency has the following parameters:

• Name
• .csv file that contains the list of targets to intercept
• NAP to use for making outgoing calls to Law Enforcement Agencies, carrying audio for intercepted call legs
• Configuration of FTP/SFTP client for uploading IRI (Intercept Related Information) records to Law Enforcement Agency's FTP or SFTP server:
  • IP address or domain name of the FTP/SFTP server
  • User name to use for FTP/SFTP server login
  • Password to use for FTP/SFTP server login
  • Remote directory to store IRI records into
  • FTP/SFTP connection timeout
  • Maximum number of IRI entries in the upload queue
  • Maximum time a IRI entry can remain in the upload queue

Creating a NAP that is connected to a Law Enforcement Agency

Create a NAP in the same way that is normally done using Toolpack. The ETSI specifications refer to ISDN NAP, but other type of NAPs are also supported by TelcoBridges. This NAP must be connected to the Law Enforcement Agency that will receive the intercepted calls.

Documentation on NAPs creation can be found here: Creating a NAP

Providing a list of targets to intercept (through a coma-separate-values .csv file)

Uploading/Modifying Lawful Intercept Targets Configuration Files (.csv)

The list of targets to intercept is provided as a .csv file. Each configured Law Enforcement Agency points to it's own .csv file.

The .csv file is uploaded from the Web Portal:

1- Click File Db in the navigation panel

2- Edit one of the listed File Db, or click "Create New File Db" to create a new one

3- In the "Lawful Intercept Targets", section click "import" (to create a new file) or "update" (to modify one of the existing files)

4- To activate a .csv file:

• Click Lawful Interception in the navigation panel.
• Select the .csv file in the appropriate Law Enforcement Agency's configuration page.

Format Lawful Intercept Targets configuration files (.csv)

The Lawful Intercept Targets configuration files must be formatted in .csv (coma-separated values) format. The following columns must be present:

• liid: Text string that uniquely identifies the target to intercept. This ID will be provided with each outgoing call on interception NAP to the Law Enforcement Agency, and in each IRI record uploaded to the FTP/SFTP server.
• number: The phone number of the target to intercept. Any call with this number as the calling, or the called number, will be intercepted.
• start: (optional) Starting date/time from which the interception can take place. Calls made before that date from/to the target won't be intercepted.
• end: (optional) End date/time where this target interception ends. Calls made after that date from/to the target won't be intercepted.

*** Warning: The column names are case sensitive

Example:

 liid,number,start,end
 John Smith,5550001,2012-10-24T00:00:00-05:00,2012-10-24T23:59:59-05:00
 Joe Dalton,14503333007,2012-01-01T00:00:00-05:00,2012-12-31T23:59:59-05:00

Enabling the Lawful Intercept routing script filter

Interpretation of the Lawful Intercept Targets configuration files (.csv) is done by a routing script filter, that can easily be added to any existing routing script used by the Toolpack system.

Documentation on routing script can be found here: Scriptable Routing Engine

Installing missing ruby 'gem'

The Lawful Intercept filter script requires the 'json' ruby gem. TMedia units (TMG800, TMG3200, TMG7800) provided by TelcoBridges are now shipped with that 'gem' already installed.

If you have an older TMedia, or if you are using your own host, please validate that the host has the 'json' gem already installed:

 gem list --local

In case it's missing, you can install it from a shell:

 gem install json

Including the Lawful Intercept filter script

The Lawful Intercept filter is activated by:

• Including the 'Lawful intercept' module in your routing script: require 'base_routing'
• Include the LawfulIntercept class: include LawfulIntercept
• Add the Lawful Intercept "after_filter" to your script: after_filter :method => :enable_lawful_intercept

Example script

Here is an example "simple routing" script that enables Lawful Intercept:

require 'base_routing'

# Insert following line ===================>
require 'lawful_intercept'

class SimpleRouting < BaseRouting
  # Insert following line ===================>
  include LawfulIntercept
 
  route_match :call_field_name => :called
  route_match :call_field_name => :calling
  route_match :call_field_name => :nap
  route_remap :call_field_name => :called, :route_field_name => :remapped_called
  route_remap :call_field_name => :calling, :route_field_name => :remapped_calling
  route_remap :call_field_name => :nap, :route_field_name => :remapped_nap
  
  # Insert following line ===================>
  after_filter :method => :enable_lawful_intercept
end

@@routing = SimpleRouting.new

def init_routes( routes )
  @@routing.init routes
end

def route( call, nap_list )
  @@routing.route call, nap_list
end

Exchanging SSH public/private keys with server to allow password-less SFTP

Toolpack can use the secure FTP (SFTP) protocol to upload IRI records to a remote server.

Please read the following documentation:

• Configure IRI (Intercept Related Information) records for SFTP upload