REX20 IP-PBX: All-in-One Phone System for Small Business | 50 Extensions, 24 Concurrent Calls | Redstone

What is the Redstone REX20?

The Redstone REX20 is an All-in-One telephony system designed for small businesses and branch offices. It provides seamless connectivity to not only PSTN and analog terminals, but also IP-based SIP trunks and SIP terminals. Using VoIP technology, the REX20 supports inter-office calls over the Internet or VPN, making it the perfect communication solution for organizations that need reliable, cost-effective voice systems without complexity.

REX20 Key Specifications:

| Parameter | REX20 |

|-----------|-------|

| Max IP Extensions | 50 |

| Max IP Trunks | 54 |

| Max Built-in Analog Extensions + Analog Trunks | 4 |

| Max Concurrent Calls | 24 |

| Size | 35 x 203 x 136 mm |

Three Core Values of REX20

1. Always Connected with Your Customers

With features such as remote extension, call forking to your mobile phone, and call-back, the REX20 assures you that no matter where you are — whether in your office, traveling abroad, or working at home — you will never miss any important business call. The system keeps your team reachable at all times, ensuring customer inquiries are never left unanswered.

2. Improving Call Answer Rate

The smart auto attendant can provide 24/7 live answering service to customers, and direct incoming calls efficiently to the extension or cell phone of the right person through configurable voice menus in business hours, non-business hours, and holidays. The system can even deliver calls from VIP customers directly to assigned agents, bypassing voice menus entirely for faster service.

3. Reduction of Telecommunications Cost

The REX20 has all the IP remote-calling functions needed to support remote workers, business travel, and communication with branches through the Internet. With IP technology, international or long-distance calls are turned into local toll-free calls. Combined with advanced routing capabilities, the REX20 can route calls intelligently according to call types. Paired with the softphone App and SoftConsole, you can achieve more effective and comfortable communications between you and your customers.

Key Features of REX20

Built-in Analog Gateway Modules

The REX20 includes built-in analog gateway modules and storage for recording, FoIP (Fax over IP), and voicemail. This means you can connect existing analog phones and fax machines directly without additional hardware.

Headquarters and Branch-Office Communication

Through SIP-based tie trunks, the REX20 enables free calls between headquarters and branch offices over the Internet or VPN, eliminating long-distance charges for internal communication.

Mobile Extensions

Mobile extensions keep you connected anywhere and anytime. Whether you are on a business trip or working remotely, your office extension travels with you.

Windows SoftConsole

The Windows-based SoftConsole provides click-to-dial, call history, and call recording capabilities, making it easy for receptionists and operators to manage high volumes of calls efficiently.

RESTful API for Third-Party Applications

XML/HTTP-based RESTful API allows seamless integration with CRM systems, hotel management software, and other business applications, extending the capabilities of your communication system.

Remote Access via Redstone Cloud

The REX20 is embedded with the Redstone Cloud client, which is based on Amazon. This allows devices located behind enterprise NAT or firewalls to be easily accessed from the Internet for maintenance, troubleshooting, or by remote voice devices. Real-time monitoring, alarm notification, remote packet capture, and software upgrading can all be performed remotely.

Remote Device Management

Management is supported through the Redstone or third-party Remote Device Management Systems using TR-069 or SNMP protocols, giving IT administrators full control over device configuration and monitoring.

NAT Traversal

Peer-to-peer communication between the Redstone IP-PBX and SIP terminals works across NAT without the need for static IP addresses, DDNS, or port mapping on the access router. This simplifies deployment significantly, especially for small businesses without dedicated IT staff.

Who Should Use the REX20?

The REX20 is ideal for:

- Small businesses with up to 50 employees needing a reliable phone system

- Branch offices of larger organizations that need to connect to headquarters

- Retail stores and small shops that want professional call handling

- Remote teams that need mobile extension and softphone capabilities

- Startups looking for an affordable, scalable communication platform

REX20 vs Other REX Models

If your business grows beyond 50 extensions, the REX series offers a clear upgrade path:

- REX50: 128 IP extensions, 30 concurrent calls — for growing businesses

- REX200: 168 IP extensions, 90 concurrent calls — for mid-size businesses and contact centers

- REX500: 400 IP extensions, 120 concurrent calls — for large enterprises

- REX1000: 1,000 IP extensions — for very large organizations

- REX8000: 10,000 IP extensions — for carrier-grade deployments

All models share the same core features, so upgrading is seamless and your team does not need to learn a new system.

Conclusion

The Redstone REX20 delivers enterprise-grade communication features in a compact, affordable package designed specifically for small businesses. With 50 IP extensions, 24 concurrent calls, built-in analog support, mobile extensions, and cloud-based remote management, the REX20 provides everything a small organization needs to communicate professionally. As your business grows, the REX series scales with you, ensuring your communication system always matches your needs.

Ready to upgrade your small business communication? Get a quote for the Redstone REX20 today and see how All-in-One IP-PBX can transform your business.