by SteveF, April 21, 2026

Most POTS replacement solutions on the market today support only 1–8 PSTN lines. This creates significant deployment challenges in environments such as apartment complexes, universities, and senior living communities, where dozens—or even more than 100—PSTN lines are required.

In these scenarios, deployments are often split into two categories:

• Standard lines, handled by conventional VoIP gateways or ATA devices
• Emergency lines, handled by dedicated POTS replacement devices with battery backup and 4G/5G redundancy

This fragmented approach increases complexity, cost, and maintenance overhead.

Vola Networks’ AGW128 and AGW32 modular gateways are designed to eliminate this challenge, enabling large-scale POTS replacement deployments with a single system.

1. Modular Design for Flexible Configuration

The AGW128 features:

• MCU (main control unit) slot
• power module slots
• battery module slots
• PSTN interface (SSU) slots

Each SSU supports 32 FXS ports, exposed via two RJ21 connectors (1–16 and 17–32), along with an RJ11 test port parallel to FXS port 1.

This modular architecture allows users to scale flexibly based on project size—reducing upfront investment while maintaining easy expansion.

2. Front Cabling & Hot-Swappable Maintenance

All connections—including power—are accessible from the front panel, simplifying installation in rack environments.

Every module in the AGW128 is hot-swappable, enabling maintenance or upgrades without service interruption. Even the cooling system is modular, with replaceable fan trays that can be serviced without downtime.

3. Dual Power Supply Design

The AGW128 supports dual power modules with flexible options:

• AC (100–240V)
• DC (48V)

Users can deploy:

• Single power supply
• Dual AC or dual DC
• Hybrid AC + DC

This redundancy significantly reduces downtime risk. In case of failure, alerts can be monitored via VolaCloud, with optional email notifications for rapid response.

4. Dual Battery Modules for 24-Hour Emergency Operation

With two battery modules, the AGW128 can support one SSU (32 PSTN lines) for up to 24 hours.

Critical lines—such as fire alarms and emergency phones—can be grouped on a dedicated SSU and configured in “emergency power mode”, ensuring uninterrupted operation during power outages.

5. Environmental Monitoring for Safety

The MCU supports multiple sensor interfaces, including:

• Fire detection
• Humidity
• Flood/water ingress
• Door status

This enables real-time environmental monitoring through VolaCloud, allowing proactive maintenance and improved operational safety.

6. KVM Remote Management Support

The AGW128 MCU includes:

• RS232 interface (RJ45 connector)
• Reset interface
• Local management port

It integrates easily with remote KVM systems, enabling efficient remote troubleshooting and control.

7. Multi-WAN Uplink with SFP Support

The AGW128 provides two WAN interfaces:

• 1 × RJ45
• 1 × RJ45/SFP combo

It supports Multi-WAN failover/failback, ensuring network resilience.

Recommended setup:

• Primary WAN → customer router
• Backup WAN → Vola LM150 (4G) or T5300 (5G)

Both devices support PoE and can be powered via the AGW128’s 12V output, ensuring continued operation during outages.

8. 5V / 12V Output for External Devices

The MCU includes:

• 1 × 5V output
• 1 × 12V output

These can power external sensors or PoE injectors. Both outputs are battery-backed, maintaining operation even during power loss.

9. Compatible modular design between AGW32 and AGW128

For less than 128 lines POTS replacement deployments, the AGW32 offers:

• Full module compatibility with AGW128
• Small size enclosure
• Single power and battery module
• 1 SSU slot (32 PSTN lines)

Up to 8 lines can be configured as emergency lines, with 24-hour backup capability.

10. Learn More or Request a Sample

Interested in learning more?

Contact your Vola Networks sales representative or reach out to our distributor, TeleDynamics.