Best Practice - Configuring SBC Edge for Compatibility with G5 LAG

The Ribbon SBC 1000/2000 supports the following objectives for enterprises:

• Connects PSTN legacy infrastructure to Skype for Business 
• Connects Teams clients to an enterprises's SIP trunk/PSTN Provider

The enterprises that deploy Microsoft Unitified Communications (UC) solutions are transitioning to all-IP network infrastructures, but often need to continue realizing investments in analog device infrastructure. The Ribbon G5 Line Access Gateway (LAG) links Time-Division Multiplexing (TDM) customers to mobile, broadband, and SIP-based and IMS services, and is compatibility tested for SBC 1000/2000 operation with Microsoft Skype for Business and Microsoft Teams. Add the G5 LAG to the network to support the integration of legacy equipment such as analog phones, modems, and fax machines into Skype or Teams deployments.

The SBC 1000/2000 is configurable from the Easy Configuration Wizard. The G5 LAG system includes TL1 (primary) and web-based administrative interfaces. This Best Practice describes SBC 1000/2000 configuration details to support using the G5 LAG for analog line aggregation with Microsoft Skype for Business and with Microsoft Teams.

Overview

The G5 LAG provides high-density, low-cost analog POTS subscriber interfaces over copper pairs. When the G5 and an SBC Edge interoperate, large quantities of FXS ports can be easily aggregated into a Microsoft solution. Ribbon's  testing of the SBC 1000/2000 and G5 LAG entailed registering G5 LAG lines on the SBC 2000 and running traffic through the SBC 2000 to observe G.711 SIP Codec operation. Testing also included performing basic calls and calls using line and routing features between G5 LAG (SIP) lines and Skype for Business communications clients.

Audience

This technical information is provided for use by qualified telecommunications engineers operating the G5 Line Access Gateway and configuring the SBC 1000/2000.  Understanding of Microsoft Skype and Teams, as well as SIP, IP/Routing, and line feature interactions is necessary to complete the product configurations and to perform troubleshooting, if necessary.

Deployment Scenarios

Ribbon, Skype for Business, and Microsoft Teams support numerous deployment scenarios to meet various customer needs. This Best Practice details the following scenarios that are likely when needs for aggregating analog lines are present:

• SBC 1000/2000 deployed with Skype for Business On-Premises
• SBC 1000/2000 deployed with Microsoft Direct Routing for Teams to support multiple, unique tenants

G5 LAG Configuration

The G5 Line Access Gateway (LAG) is a SIP gateway that terminates copper lines. A shelf of a G5 LAG system contains 24 universal slots for POTS-32 line cards. Each POTS-32 card supports 32 lines, enabling a G5 LAG system to support up to 768 POTS subscribers. For a G5 LAG that handles FAX calls, timing synchronization is recommended; timing synchronization is provided over available DS-1 interfaces. 

To configure a G5 LAG system for interoperation with SBC Edge, the G5's proxy IP address must be provisioned with the realm IP address of the SBC Edge. 

A persistent TL1 management connection to a G5 LAG provides access to alarms and events from an Operational Support System (OSS) using TL1 commands. The G5 LAG also supports alarms forwarding via SNMP to a customer-provided trap receiver. For more information about the G5 LAG, refer to the Ribbon G5 Line Access Gateway System Description (630-01621-01).

G5 LAG Ports and Protocols

Ribbon recommends configuring the G5 LAG with SIP interface with two IP addresses, one for OAM and SIP signaling and one for RTP/bearer traffic. The two IP addresses must reside in the same subnet. During operation, the two addresses reside on one of the network ports (the one actively forwarding traffic).

The following table summarizes the ports provided by the G5 LAG.

G5 LAG Deployment for Interoperability

 The following figure illustrates a G5 LAG  with a standalone Application Server in a configuration with an SBC 2000 supporting a Microsoft Unified Communications (UC) deployment.

G5 LAG with Application Server Supporting a Microsoft UC Deployment

 

 SBC Edge Configuration

You can use existing SBC Edge components with a G5 LAG system or set up a new SBC Edge component. 

Prerequisites

For an existing SBC Edge, be sure to define any interfaces that are not already defined and to configure the Ethernet 2 IP interface with the IP address used for external access to the Service Provider. For more information, see Configuring and Modifying Logical Interfaces.

Setup or Update an SBC Edge Configuration for G5 LAG Interoperation

To prepare for SBC 1000/2000operation with a G5 LAG system, perform the following steps:

1. If you are adding a new SBC Edge component, complete the initial set up of the SBC Edge, addressing the following items in the appropriate sequence:

   1. In the navigation panel of the WebUI, click Protocols > IP Static Routes, then press "+" to add a static IP route entry for the default route. This is the route for any traffic destined for the IP adresses that are not within the internal range of the SBC.

   2. For the Gateway field, specify the IP address for Interface 2, or the default gateway of the perimeter network in which Interface 2 is configured, if behind a NAT. For more information, refer to Configuring and Modifying Logical Interfaces.

2. For an SBC 1000/2000, log into the WebUI and launch the Easy Configuration Wizard from the Tasks tab.
3. In the first step of the Easy Configuration, click the drop-down arrow to choose the Application that matches your deployment scenario; choose SIP Trunk and the appropriate Microsoft UC client type (Skype for Business or Teams).
4. Follow the instructions in the Wizard to complete the remaining configuration steps. For more information, refer to Configure SIP Trunk with Microsoft On Premises.
5. Create new Transformation Tables for the following types of calls. Refer to Managing Transformation Tables for more information.
   1. Calls from the G5 LAG to Microsoft UC
   2. Calls from the G5 LAG to a SIP trunk
   3. Calls from the G5 LAG to a G5 LAG extension
6. Create new Call Routes to support the Transformation Tables created in Step 5. Refer to Managing Call Routing Tables for more information.

7. Create a local registrar for the G5 LAG system. For more information, refer to Creating and Modifying Local SIP Registrars.

8. Add a new SIP Signaling Group to perform as local registrar (that is, a SIP Registrar), for the G5 LAG system. Refer to Creating and Modifying SIP Signaling Groups for more information.

9. To prepare for configuring Access Control List (ACL) rules that pinhole the enterprise firewall to allow and deny connections on the SBC appropriately, gather the following information for the endpoint and media protocol from your PSTN Service Provider:
   1. signaling endpoint public IP address
   2. signaling endpoint port
   3. protocol used on signaling endpoint
   4. media endpoint IP address   
   5. media port range
   6. protocol used on media endpoint
      Note: Consider whether you need the information listed for inbound sessions and for allowing signaling and media out.
10. On the Settings tab, go to Protocols  > IP > Access Control Lists, then press "+" to add an ACL rule for allowing traffic on inbound/outbound ports. For more information, refer to Managing Access Control Lists.
    1. Specify a meaningful name for the ACL rule in the Description field
    2. Choose  Allow in the Action field, and choose Range as the Port Selection Method. 
    3. Type the port and protocol information from the Service Provider into the fields for the Source and Destination fields.
11. Repeat Step 10 using the information for creating outbound ACL rules to allow signaling and media out, if necessary.
12. With the G5 LAG and your Microsoft UC deployment connected, perform test calls and check line feature operation to confirm the success of the legacy infrastructure integration.