PBX Remote Line Extension

This configuration note explains how to configure Mediatrix units in a PBX Remote Line Extension scenario.

With VoIP, the distance limitation of extending copper wire from a PBX to a remote location is no longer an issue. Small remote branch offices (SOHOs) can now have existing analog phones installed at the remote site as analog extensions of the PBX system at the Main Office.

In this scenario, we consider that 4 extensions of the PBX need to be relocated to a remote site. Therefore,
  • when a PBX user/extension initiates a call to one of the four (4) extensions, the extensions will ring on the remote site and vice versa:
  • when one of the four (4) extensions on the remote site initiates a call, that call will be routed to the PBX, as if it was a local extension.
Additionally, the remote site has their analog telephone devices connected to two FXS Mediatrix units.

The routes are configured on the FXO unit, and the FXS port, corresponding to a phone extension, are configured on the FXS units.


Information to Know Before Starting

Before starting to use these configuration notes, complete the following table to make sure you have the required information to complete the different steps.

IMPORTANT: If you are not familiar with the meaning of the fields and buttons, click Show Help, located at the upper right corner of the Web page. When activated, the fields and buttons that offer online help will change to green and if you hover over them, the description will bedisplayed.
Note: The Mediatrix unit must be reinitialised to its factory default settings to make sure the configuration can be successfully executed.
Information Value Used in Step
IP address used by your Mediatrix unit to communicate with the Management Interface.
  • If your computer is connected to the Ethernet port meant to be connected to the Local Area Network (LAN), i.e. Eth2 on most devices
Use this value Logging on to the Mediatrix Unit Web Interface
  • If your Mediatrix unit is configured to use a DHCP server, use the DHCP server- provided IP address.
Logging on to the Mediatrix Unit Web Interface
IP address of the FXO Mediatrix unit Linking the FXS Unit to the FXO Unit
IP address of the FXS Mediatrix unit Linking the FXO Unit to the FXS Unit



Logging on to the Mediatrix Unit Web Interface

Before you begin
The computer IP address must be in the same TCP/IP network as the Mediatrix unit.
About this task
For better performances, it is recommended to use the latest available version of Microsoft Internet Explorer, Google Chrome, or Mozilla Firefox.
Note: You may not be able to log on to the Mediatrix unit Web interface if you are using older browser versions.
  1. In your Web browser, enter the IP address at which the Web interface of your Mediatrix unit can be reached.
    • If your network has an IPv4 DHCP server, connect the primary Ethernet port of the Mediatrix unit to the network (ETH1 port), use the provided DHCP server IP address.
    • You can also connect your computer to the secondary Ethernet port of the Mediatrix unit (ETH2), use the IP address. However, the computer must also own an IP address in the network.
  2. Enter admin as your username and administrator as the password.
    Note: You can also use public as a username and leave the password field empty; it has the full administration rights by default.
  3. Click Login.
The Information page of the Web interface is displayed.


Configuring the FXS Unit

Linking the FXS Unit to the FXO Unit

  1. Go to SIP/Servers.
  2. In the Default Servers table, in the Proxy Host field, enter the IP address of the FXO unit.
  3. Leave the other fields empty.
  4. Click Apply.
  5. Click restart required services.


Disabling Endpoint Registration

  1. Go to SIP/Registrations.
  2. In the Endpoints Registration table, for all used endpoints, set the Register field to Disable.
    Note: The endpoints that are used have a defined User Name. By default unused endpoints are disabled.
  3. Click Apply and Refresh.
  4. Click restart required services located at the top of the page.
Disabled endpoints will no longer be registered individually.


Configuring the FXO Mediatrix Unit

Configuring a Route from sip-default to FXO

  1. Go to Call Router/Route Config .
  2. In the Routes table, click .
  3. In the Sources field, type sip-default .
  4. In the Criteria Property drop box, select Calling E164.
  5. In the Criteria Rule field, set the first extension.
  6. In the Destination drop box, select the first FXO port.
  7. Repeat the tasks 2 to 6 for each extension.
  8. Click Save.
Calls incoming from the remote site to the Mediatrix FXS unit, will be routed to the proper FXO port of the FXO Mediatrix unit, according to the calling number/extension. Calls coming form the PBX to the FXO Mediatrix unit and having a called E164 specific extension, will be routed to the remote site.


Configuring a Route from FXO to sip-default

  1. Go to Call Router/Route Config .
  2. In the Routes table, click .
  3. In the Sources field, from the Suggestion selection list select every FXO port used at the previous step.
  4. In the Criteria Property drop box, select None.
  5. Leave the Criteria Rule field empty.
  6. In the Destination drop box, select sip-default.


Linking PBX Analog Extensions to Specific FXS Endpoints in Remote FXS Unit

  1. Go to Telephony/Services.
  2. At the top of the page, in the Select Endpoint drop box, choose the first FXO endpoint.
  3. In the Automatic Call section, from the Endpoint Specific drop box, select Yes.
  4. In the Automatic Call Activation drop box, select Enable.
  5. In the Automatic Call Target field, type the URI.
    Note: The URI is made up of the sip prefix, the extension number, and of the IP address of the target FXS Mediatrix unit that has this extension configured, for example: sip:210@
  6. Repeat the steps 2 to 5 for each FXO endpoint of the FXO Mediatrix unit.
    Note: An FXO endpoint can only be linked to one FXS endpoint, and vice versa.
  7. Click Apply.
The Mediatrix unit redirects the call to a specific SIP endpoint upon off-hook.


Configuring the Dial Tone Detection

It allows the Mediatrix unit to wait for a dial tone before initiating the dialing sequence. If no dial tone is detected, the line is considered busy.
  1. Go to POTS/FXO Configuration.
  2. In the FXO Dialing Configuration table, from the Dial Tone Detection Mode drop box, select CountryTone.
    Note: Not all PBX manufacturers produce the country dial tone on the extension line. If this is the case, make sure the Dial Tone Detection Mode is disabled, otherwise the Mediatrix unit will not output dialed digits.
    Note: Not all PSTN switches produce the country dial tone on the PSTN line. If this is the case, make sure the Dial Tone Detection Mode is disabled, otherwise the Mediatrix unit will not output dialed digits.
  3. Click Apply.


Configuring the Answering Delay

  1. Go to POTS/FXO Configuration.
  2. In the FXO Answering Configuration table, complete the fields as required.
    Note: If the PBX does not pass the caller ID to the Mediatrix unit, you can reduce the Wait Before Answering Delay to 2500 to reduce the time before the Mediatrix unit goes off-hook upon ring detection.
  3. Click Apply.


Configuring the Far End Disconnect Parameters


  1. Go to POTS/FXO Configuration.
  2. In the FXO Force End of Call table, from the Force End Of Call On Tone Detection Mode drop box, select Custom Tone.
  3. Set the Tone Detection Custom Frequency field to 350.
    Note: Verify with your PBX supplier what tone (exact frequency and cadence) the PBX produces on the extension when the far end is disconnected.
  4. Complete the other fields as required.
  5. Click Apply.


Testing the Configuration

Making a Call in Both Directions

  1. Connect an analog phone to a port of the FXS Mediatrix unit.
  2. Pick up the phone.
    You must hear a dial tone.
  3. Dial any valid extension number of your PBX.
    The dialled extension must ring.
  4. Pickup a phone on the PBX and dial one of the extensions configured on the Mediatrix unit.
    The analog phone corresponding to the extension must ring.


DGW Documentation

Mediatrix devices are supplied with an exhaustive set of documentation.

Mediatrix user documentation is available on the Media5 Documentation Portal.

Several types of documents were created to clearly present the information you are looking for. Our documentation includes:
  • Release notes: Generated at each GA release, this document includes the known and solved issues of the software. It also outlines the changes and the new features the release includes.
  • Configuration notes: These documents are created to facilitate the configuration of a specific use case. They address a configuration aspect we consider that most users will need to perform. However, in some cases, a configuration note is created after receiving a question from a customer. They provide standard step-by-step procedures detailing the values of the parameters to use. They provide a means of validation and present some conceptual information. The configuration notes are specifically created to guide the user through an aspect of the configuration.
  • Technical bulletins: These documents are created to facilitate the configuration of a specific technical action, such as performing a firmware upgrade.
  • Hardware installation guide: They provide the detailed procedure on how to safely and adequately install the unit. It provides information on card installation, cable connections, and how to access for the first time the Management interface.
  • User guide: The user guide explains how to customise to your needs the configuration of the unit. Although this document is task oriented, it provides conceptual information to help the user understand the purpose and impact of each task. The User Guide will provide information such as where and how TR-069 can be configured in the Management Interface, how to set firewalls, or how to use the CLI to configure parameters that are not available in the Management Interface.
  • Reference guide: This exhaustive document has been created for advanced users. It includes a description of all the parameters used by all the services of the Mediatrix units. You will find, for example, scripts to configure a specific parameter, notification messages sent by a service, or an action description used to create Rulesets. This document includes reference information such as a dictionary, and it does not include any step-by-step procedures.


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