PRI Configuration for IP PBX Deployment

Contents

Introduction

The following example demonstrates a complete T1 net-side PRI to IP PBX deployment using an Edge 8300 model and the Edge 8000 Series 24.1 software release. The example includes screenshots and specific values for all the major configuration areas, including:

• Setup Wizard
• SWe Edge and Analog Licensing
• SWe Edge provisioning
• PRI settings
  

For additional information:

• Refer to Workflow for Initial Setup for the entire provisioning process, including physically Installing Edge 8000 Hardware.
• See Considerations for Other PRI Applications at the end of this article for:
  • T1 user-side applications
  • E1 net-side applications
  • E1 user-side applications

While the goal of this example is not to provide a detailed configuration that meets the needs of every scenario, it does provide a starting point for building a customized configuration for a PRI to IP PBX deployment.

Network and Call Flow Diagrams

In this demonstration, an Edge 8000 Series 8300 product is configured to support two Signaling Groups:

• On the digital TDM side, a TDM phone connects to a PRI PBX which connects to a PRI port on the Edge 8000 device. The Signaling Group To/From SIPUA_PRI serves this side.
• On the private or LAN side, an IP phone connects to an IP PBX which connects to a gigabit Ethernet port on the Edge 8000 device. The Signaling Group To/From IP PBX serves this side.

The following diagrams depict the network topology, network interfaces, and call flows of this demonstration.

Network Topology

Network Interfaces for a T1 Net-Side PRI Application

Signaling and Media Call Flows

Setup Wizard Values

After physically installing the Edge 8000 device, you use the Setup Wizard to establish basic platform settings.

The following tables show the values applied in Setup Wizard for this demonstration. Consult your network design team for specific values appropriate for your own network.

System Configuration

Bridge Settings (BR1-4)

Gigabit Ethernet Settings (GE1-8)

Small Form-factor Pluggable (SFP9-10)

Default Gateway

SWe Edge Settings

SWe Edge and Analog Licenses

In this demonstration, the Edge 8300 device employs SWe Edge and Analog licenses.

To view the licenses, open a browser and enter the Edge 8000 webUI IP address, then log in as user admin.

Click the Settings tab and navigate to System > Licensing > Current Licenses.

The following screenshots illustrate the Analog and SWe Edge licenses employed for this demonstration.

Analog License Features

SWe Edge License Features

SWe Edge Configuration

Networking Interface Values

Networking Interfaces define the way the SWe Edge component within the Edge 8000 device communicates with internal and external networks. 

The Edge 8300 device supports system-created SWe Edge logical interfaces as follows:

• Admin IP – an internal logical address that supports management access to the SWe Edge; it is pre-set at the factory and not configurable
• Ethernet 1 IP – a logical address that supports a connection to the LAN IP PBX; enter the IP address manually using the Edge 8000 webUI
• Ethernet 1.2626 IP – a logical address that supports a connection to a VLAN logical sub-interface to the LAN IP PBX; enter the IP address manually using the Edge 8000 webUI
• Ethernet 2 IP – an internal logical address that supports a connection to the PRI ports; it is pre-set at the factory and not configurable

The following table summarizes the Networking Interfaces used for this demonstration.

Networking Interface Assignments

To display Networking Interfaces in the webUI:

• click the Settings tab
• navigate to SBC > Networking Interfaces > Logical Interfaces

The following screenshots illustrate the logical Networking Interfaces defined for this demonstration.

Networking Interfaces

Example of a Networking Interface: Ethernet 1.2626 IP

Static Route Values

Static routes enable communication with remote networks. In a production environment, you configure static routes mainly for routing from one specific network to another network that can only be accessed through one point or one interface (single path access or default route).

In this demonstration, a Static Route definition gives access to the IP PBX.

Static Route fields include:

• Destination IP – specifies the destination IP address.
• Mask – specifies the network mask of the destination host or subnet. (If the Destination IP Address and Mask fields are both 0.0.0.0, the static route is called the "default static route.")
• Gateway – specifies the IP address of the next-hop router to use for this static route.

To display Static Routes in the webUI:

• click the Settings tab
• navigate to SBC > Protocols > IP > Static Routes

The following screenshot illustrates the Static Routes defined for this demonstration.

Static Routes

Signaling Groups

Signaling Groups allow telephony channels to be grouped together for routing purposes and for shared configurations. Signaling Groups are the locations from which ingress calls enter and to which egress calls route out. They also specify which Tone Table to use. In the case of SIP, they specify protocol settings and are linked to server, media, and mapping tables.

The following diagram depicts the role of Signaling Groups in a typical call flow. Every call enters through an ingress Signaling Group, traverses through a Call Routing Table and its associated Transformation Table or Tables, and exits through an egress Signaling Group. For each Signaling Group, a SIP Server Table or Local Registrar defines where the call should go on egress.

SIP to SIP Call Flow Sequence

In this demonstration, two Signaling Groups are defined :

• To/From IP PBX Signaling Group – serves the LAN-side IP PBX and associated IP phones
• To/From SIPUA_PRI Signaling Group – serves the TDM-side PRI PBX and associated TDM phones
  

The following fields must be modified, as a minimum, for each Signaling Group:

• SIP Profile
• Tone Table
• Call Routing Table
• SIP Mode
• SIP server table / Local Registrar
• Media List ID
• Signaling/Media Source IP
  
• Listen Ports
• Federated IP/FQDN
  

Ensure that you set the following parameters specifically for the Signaling Group being defined and correctly per your network plan:

Additional fields may be modified per end-user requirements. 

To display Signaling Groups in the Edge 8000 webUI:

• click the Settings tab
• navigate to SBC > Signaling Groups

The following screenshots illustrate the Signaling Groups defined for this demonstration.

To/From IP PBX Signaling Group

To/From SIPUA_PRI Signaling Group

The physical PRI port connects internally to a SIP User Agent which converts ISDN to SIP protocol. In this way, inbound PRI calls are converted to SIP and presented as another SIP signaling group to the SWe Edge. (See the SIP User Agent (SIPUA) component in the diagram Network Interfaces for a T1 Net-Side PRI Application.)

For this demonstration, this Signaling Group is named To/From SIPUA_PRI. See the preceding diagrams, Network Topology, Network Interfaces for a T1 Net-Side PRI Application, and Signaling and Media Call Flows, for illustrations of the To/From SIPUA_PRI Signaling Group.

SIP Profiles

SIP Profiles control how the Edge 8000 device communicates with other SIP devices. SIP Profiles control important characteristics such as session timers, SIP header customization, SIP timers, MIME payloads, and option tags.

In this demonstration, two SIP Profiles are defined, one for each Signaling Group:

• To/From IP PBX Profile – serves the To/From IP PBX Signaling Group
• Default SIP Profile – serves the To/From SIPUA_PRI Signaling Group
  

To display SIP Profiles in the Edge 8000 webUI:

• click the Settings tab
• navigate to SBC > SIP > SIP Profiles

The following screenshots illustrate the two SIP Profiles used for this demonstration.

To/From IP PBX Profile

This SIP Profile serves the To/From IP PBX Signaling Group.

Default SIP Profile

This SIP Profile serves the To/From SIPUA_PRI Signaling Group.

Tone Tables

Tone Tables allow the Edge 8000 administrator to customize the tones a user hears when placing a call. You can modify the tone to match your local PSTN or PBX requirements. The default Tone Table is configured for the values used in the United States for the following categories: Ringback, Dial, Busy, Congestion, Call Waiting, Disconnect, and Confirmation.

In this demonstration, each Signaling Group uses a unique Tone Table:

• United States Tone Table – serves the To/From IP PBX Signaling Group
• Default Tone Table – serves the To/From SIPUA_PRI Signaling Group
  

To display Tone Tables and associated profiles in the Edge 8000 webUI:

• click the Settings tab
• navigate to SBC > Tone Tables
  

The following screenshots illustrate the Tone Table and associated Tone Profiles defined for this demonstration.

United States Tone Table

Default Tone Table

Ringback Tone Profile

Congestion Tone Profile

Transformation Tables

Transformation Tables facilitate the conversion of names, numbers, and other fields when routing a call. They can, for example, convert a public PSTN number into a private extension number or into a SIP address (URI). Every entry in a Call Routing Table requires a Transformation Table.

In this demonstration, two Transformation Tables are defined:

• Transformation Table, IP PBX Numbers
  
  • supports the Call Routing Table, To/From IP PBX
  • matches the telephone number ranges set on the IP PBX for the IP phones
    
• Transformation Table, PRI Numbers
  
  • supports the Call Routing Table, To/From SIPUA_PRI
    
  • matches the telephone number ranges set on the PRI PBX for the TDM phones
    

To display Transformation Tables in the Edge 8000 webUI:

• click the Settings tab
• navigate to SBC > Call Routing > Transformation

The following screenshots show the two Transformation Tables defined for this demonstration.

Transformation Table – IP PBX Numbers

Transformation Table – PRI Numbers

Call Routing Tables

Call Routing Tables allow calls to be carried between signaling groups, thus allowing calls to be carried between ports and between protocols. Call Routing Tables define routes, which allow for flexible configurations of which calls are carried and how they are translated. The Call Routing Tables are one of the central connection points of the system, linking Transformation Tables, Message Translations, Cause Code Reroute Tables, Media Lists, and the Signaling Groups.

In this demonstration, two Signaling Groups are defined, each with its own Call Routing Table.

Signaling Group and Matching Call Routing Table and Transformation Table

The following fields of the Call Routing Table must be modified as a minimum:

• Description
• Number/Name Transformation Table
• Destination Signaling Groups

Additional fields may be modified per end-user requirements.

To display Call Routing Tables in the webUI:

• click the Settings tab
• navigate to SBC > Call Routing > Call Routing Table

The following screenshots show the two Call Routing Tables defined for this demonstration: From IP PBX and From SIPUA_PRI. 

 Call Routing Table – From IP PBX

This Call Routing Table, From IP PBX, contains an entry for the PRI Numbers Transformation Table.

Call Routing Table – From SIPUA_PRI  

This Call Routing Table, From SIPUA_PRI, contains an entry for the IP PBX Numbers Transformation Table.

SIP Server Tables

SIP Server tables contain the IP address or FQDN of one or more SIP servers where INVITE messages can be sent to egress calls on a Signaling Group. The entries in the tables provide information about the IP Addresses, ports, and protocols used to communicate with the servers. The entries also contain links to counters that are useful for troubleshooting.

In this demonstration, two SIP Server Tables are defined:

• SIP Server Table, IP PBX – serves the To/From IP PBX Signaling Group
  
• SIP Server Table, SIPUA_PRI – serves the To/From SIPUA_PRI Signaling Group

The following fields of the SIP Server Table must be modified as a minimum:

• Host FQDN/IP
• Port
  
• Protocol
  

Additional fields may be modified per end-user requirements.

To display SIP Server Tables in the webUI:

• click the Settings tab
• navigate to SBC > SIP > SIP Server Tables
  

The following screenshot shows the two SIP Server Tables created for this demonstration. 

SIP Server Table – IP PBX

Here, 10.35.180.111 is the IP address of the IP PBX.

SIP Server Table – SIPUA_PRI 

Here, 169.254.1.50 is the hard-coded (non-configurable) internal IP address allocated to PRI for SIP User Agent signaling to the SWe Edge. The port number must be 1025. (See the SIP User Agent (SIPUA) component in the diagram Network Interfaces for a T1 Net-Side PRI Application.)

Local Registrar 

Media Profiles

Media Profiles allow you to specify voice and fax compression codecs and their associated settings for inclusion in a Media List. Different codecs provide varying levels of compression, allowing a tradeoff between reducing bandwidth at the expense of reducing voice quality.

The following field of a Media Profile must be modified as a minimum:

• Codec
  

Additional fields may be modified per end-user requirements.

To display Media Profiles in the webUI:

• click the Settings tab
• navigate to SBC > Media > Media Profiles

The following screenshots show the Media Profiles created for this demonstration.

IP PBX: G.711 A-Law

IP PBX: G.711 Mu-Law 

IP PBX: G.729

Default G.711 A-Law

Default G.711 Mu-Law

Media Lists

A Media List contains a list of media profiles ordered to give preference to more desirable codecs above less desirable ones. Profile order determines the order in which codecs are specified in SIP message(s) sent to a peer.

The following field of a Media List must be modified as a minimum:

• Media Profiles List

Additional fields may be modified per end-user requirements.

To display Media Lists in the Edge 8000 webUI: 

• click the Settings tab
• navigate to SBC > Media > Media List

The following screenshots show two Media Lists created for this demonstration:

• IP PBX List – used by the To/From IP PBX Signaling Group
• Default Media List – used by the To/From SIPUA_PRI Signaling Group

IP PBX List

The To/From IP PBX Signaling Group uses this Media List.

Default Media List

The To/From SIPUA_PRI Signaling Group uses this Media List.

PRI Configuration

Before PRI ports can be used for calls, they must be enabled and configured through the PRI-Setting menus of the Edge 8000 webUI. For this demonstration the PRI-Setting menus include:

• T1-Common Setting
  
• T1-Configuration
  
• Net-Side

In this demonstration, T1 line 0 is configured for net-side use.

T1-Common Setting

The following fields of the T1-Common Setting menu must be modified:

• Framing-Mode. Specifies the transmission framing mode for all the lines.
• Line-Encoding. Specifies the bit encoding method for all the lines.
  

  The field SIP-SERVER-IP is hard-coded to the value 169.254.1.120 and cannot be configured. This is the IP address of the Ethernet 2 port of the SWe Edge for internal SIP communication with PRI/FXS/FXO ports.

  
  

To display the T1-Common Setting menu in the webUI:

• click the Settings tab
• navigate to Gateway > PRI-Setting > T1-Common Setting
  

The following screenshot shows the T1-Common Setting values for this demonstration:

T1-Common Setting

T1-Configuration

 For each line being used, the following field of the T1-Configuration menu must be modified:

• PRI-Enable. Activates the PRI port.  It must be set to True.

To display the T1-Configuration lines in the webUI:

• click the Settings tab
• navigate to Gateway > PRI-Setting > T1-Configuration

The following screenshots show the T1:0 line in the T1-Configuration menu as configured for this demonstration.

T1-Configuration Settings

Net-Side

Configure the following Net-Side parameters for PRI-Line:0:

• T1-Trunk-Switch-Type. Enter the switch type that client-side ISDN PRI will be simulating. NI2 is selected by default. The switch type must match the Network-side switch type to which this interface is connected.
• Internal-Clocking. Select the Internal clocking for PRI.  Set to True.
• Register-With-SIP-Server. Enable Register with SIP server if your SIP service provider requires endpoints to be registered.  Set to False.
• Codec-Preference. Select the preferred codec.
  

To configure the Net-Side settings in the webUI:

• click the Settings tab
• navigate to Gateway > PRI-Setting > Net-Side

The following screenshots show PRI-Line:0 in the Net-Side menu as configured for this demonstration.

Net-Side Settings

Considerations for Other PRI Applications

Configuring an Edge 8000 device for a T1 user-side application or an E1 net-side or user-side application is similar to configuring the device for a T1 net-side application. The key difference is in the selection of the PRI type during Setup Wizard.

As explained in the Additional Notes in Complete the System Menu in the Running Setup Wizard - Standalone (or Complete the System Menu in Running Setup Wizard - High Availability), during Setup Wizard the user has four choices – T1Net, E1Net, T1User, or E1User – when selecting the PRI type:

The following topics address points to remember when configuring the PRI interfaces for a T1 user-side application or an E1 user-side or net-side application. 

T1 User-Side Application

In the case of a T1 user-side application, the internal SIP Gateway manages the calls originating from or terminating to the T1 PRI port.  The following figure illustrates the Edge 8300 network interfaces deployed in a typical T1 user-side application. Consult your network administrator and ISDN provider for the actual IP address assignments (br1, br2, Ethernet 1, Ethernet 1.2626) and PRI settings appropriate for your network.

Network Interfaces for a T1 User-Side PRI Application

Menus available for a T1 user-side application include:

E1 Net-Side or User-Side Application

In the case of an E1 application, the Edge 8000 device can be configured for a net-side or user-side application. The configuration is very similar to a T1 application, with parameters chosen from the E1-Common Setting, E1-Configuration, and either User-Side or Net-Side menus.

Menus available for an E1 net-side or user-side application include: