What is an IP-PBX System? Complete Guide to Redstone REX Series | Redstone

What is an IP-PBX System?

An IP-PBX (Internet Protocol Private Branch Exchange) is a modern telephone system that uses internet protocol to manage voice communications within an organization. Unlike traditional PBX systems that rely on copper wires and analog signals, IP-PBX systems transmit voice data over the internet or internal networks, offering greater flexibility, lower costs, and advanced features.

Key differences between IP-PBX and traditional PBX:

- IP-PBX uses VoIP technology, while traditional PBX uses analog copper lines

- IP-PBX supports remote workers and mobile extensions natively

- IP-PBX integrates with software applications through APIs

- IP-PBX reduces long-distance and international calling costs significantly

- IP-PBX scales easily without requiring new physical infrastructure

Introducing the Redstone REX Series

Redstone offers a comprehensive lineup of IP-PBX systems designed to meet the needs of businesses of all sizes. The REX series ranges from the compact REX20 for small businesses to the powerful REX8000 for carrier-grade deployments.

REX Series Overview:

| Model | Max IP Extensions | Max IP Trunks | Built-in Analog Ports | Concurrent Calls | Size |

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

| REX20 | 50 | 54 | 4 | 24 | 35x203x136mm |

| REX50 | 128 | 140 | 12 | 30 | 41x286x161mm |

| REX200 | 168 | 216 | 48 | 90 | 44x440x260mm |

| REX200-A | 298 | 300 | 48 | 100 | 44x440x260mm |

| REX500 | 400 | 496 | 96 | 120 | 85x440x300mm |

| REX500-A | 900 | 996 | 96 | 120 | 85x440x300mm |

| REX1000 | 1,000 | 1,000 | N/A | 200 | 44x440x300mm |

| REX8000 | 10,000 | 10,000 | N/A | 800 | 88x442x420mm |

Core Features Across All REX Models:

All REX series IP-PBX systems share a robust set of features that make them ideal for modern business communication:

1. All-in-One Design

Every REX model provides seamless connectivity to PSTN lines, analog terminals, IP-based SIP trunks, and SIP terminals. This hybrid approach ensures businesses can transition to VoIP at their own pace without discarding existing equipment.

2. Mobile Extensions

With features like remote extension, call forking to mobile phones, and call-back, REX ensures you never miss important business calls whether you are in the office, traveling abroad, or working from home.

3. Smart Auto Attendant

The intelligent auto attendant provides 24/7 live answering service, efficiently directing incoming calls to the right person through configurable voice menus. VIP customers can even bypass menus and connect directly to assigned agents.

4. Cost Reduction

REX converts international and long-distance calls into local toll-free calls over the internet. Advanced routing capabilities intelligently route calls according to type, further reducing telecommunications costs.

5. Remote Management

Embedded with the Redstone Cloud client (based on Amazon), devices behind enterprise NAT or firewalls can be easily accessed for maintenance and troubleshooting. Real-time monitoring, alarm notification, remote packet capture, and software upgrading are all supported.

6. Third-Party Integration

XML/HTTP-based RESTful API enables seamless integration with CRM systems, hotel management systems (PMS), and other business applications.

7. NAT Traversal

Peer-to-peer communication between Redstone IP-PBX and SIP terminals works across NAT without requiring static IP addresses, DDNS, or port mapping on the access router.

8. Unified Management

Support for TR-069 and SNMP protocols allows integration with Redstone or third-party Remote Device Management Systems.

Enhanced Features for Enterprise Models (REX500/REX1000):

- IMS Network Connectivity: Connect to operator IMS networks via ONU

- Dual-Redundant Gigabit Ethernet: 1+1 redundancy for maximum uptime

- Dual AC/DC Power Supplies: Optional redundant power for critical deployments

- Class I Lightning Protection: Industrial-grade protection for outdoor installations

- High Availability: Primary-standby, active-standby, and PSTN failover configurations

How to Choose the Right REX Model:

Small Business (1-50 employees): REX20

The REX20 is an All-in-One telephony system perfect for small businesses and branch offices. With 50 IP extensions, 54 SIP trunks, and 24 concurrent calls, it provides everything a small team needs at an affordable price point.

Growing Business (50-200 employees): REX50 or REX200

The REX50 supports 128 IP extensions and 30 concurrent calls, making it ideal for growing businesses. The REX200 expands this to 168 IP extensions and 90 concurrent calls, with the added benefit of supporting up to 60 contact center agents.

Mid-Size Enterprise (200-500 employees): REX500

The REX500 supports 400 IP extensions and connects to operator IMS networks. With dual-redundant networking and power options, it delivers carrier-class reliability for organizations where communication downtime is not an option.

Large Enterprise (500-1,000 employees): REX1000

The REX1000 supports 1,000 extensions in a compact 1U rack-mountable design. Multi-site networking capabilities allow extensions to scale to thousands across multiple locations.

Carrier/Service Provider (1,000+ extensions): REX8000

The REX8000 is designed for carrier-grade deployments, supporting up to 10,000 IP extensions and 10,000 IP trunks with 800 concurrent calls.

Conclusion

The Redstone REX series offers a complete range of IP-PBX solutions that grow with your business. From the compact REX20 to the carrier-grade REX8000, every model delivers the core features businesses need: mobile connectivity, cost savings, remote management, and seamless integration. With support for both analog and IP terminals, the REX series makes the transition to modern VoIP communication smooth and risk-free.

Ready to upgrade your business communication? Contact Redstone today for a personalized quote and discover which REX model is right for your organization.