The HT813 is an analogue telephone adapter featuring 1× FXS port and 1× FXO port, enabling remote call origination and termination to and from the PSTN line. The FXS port extends VoIP service to one analogue device, allowing users to take advantage of VoIP on their existing analogue handsets. Where most ATAs provide only FXS or only FXO functionality, the HT813’s hybrid design means a single device handles both — connecting an analogue desk phone to a VoIP platform while simultaneously keeping a PSTN line available for backup or outbound calling.

Key Highlights

• 1× RJ11 FXS port for connecting an analogue phone or fax machine
• 1× RJ11 FXO port for connecting a PSTN telephone line
• 2 SIP profiles supported across the FXS and FXO ports
• Dual 100Mbps WAN and LAN ports
• Ultra-compact desktop form factor — minimal desk footprint

PSTN Lifeline & Failover Protection

The HT813 features lifeline support — the FXS port is hard-relayed to the FXO port in the event of a power outage, ensuring a connected analogue phone can still make and receive PSTN calls even when power or internet connectivity is lost. This makes it particularly well-suited to South African deployments where load shedding is a routine consideration. A failover SIP server capability automatically switches to a secondary server if the primary loses connection, adding a further layer of telephony resilience.

• PSTN lifeline — FXS hard-relays to FXO port during power outage
• Failover SIP server for automatic switchover if the primary SIP server goes offline
• Simultaneous VoIP and PSTN line connectivity
• Supports remote calling to and from the PSTN line via the FXO port

HD Voice, Fax & Codec Support

The HT813 delivers HD voice quality through wideband codec support, with a broad range of standard codecs ensuring compatibility across different VoIP platforms and SIP trunk providers. T.38 compliant Fax-over-IP is supported for reliable fax transmission across VoIP links, with automatic G.711 pass-through fallback ensuring compatibility with legacy fax infrastructure.

• HD voice quality with wideband audio codec support
• G.711 (Annex I/II), G.723.1, G.729A/B, G.726, iLBC codec support
• T.38 Fax-over-IP with G.711 fax pass-through fallback
• G.168-compliant echo cancellation and dynamic jitter buffer for clear voice quality
• Layer 2 (802.1Q VLAN) and Layer 3 (ToS, DiffServ, MPLS) QoS support

Rich Telephony Features

Telephony features include caller ID display and block, call waiting, call transfer (blind and attended), call forward, hold, do not disturb, and 3-way conferencing — covering the full feature set expected of a business desk phone, delivered through the analogue handset already in use.

• Caller ID, call waiting, call transfer, call forward, hold, and DND
• 3-way conferencing
• Message waiting indication and multi-language prompts
• Flexible dial plans for call routing control

Security & Easy Management

Strong AES encryption with a unique security certificate per unit protects all calls and credentials. Multiple provisioning methods including TR-069, HTTP, HTTPS, and TFTP make automated mass deployment straightforward, and the HT813 is compatible with GDMS — Grandstream’s free cloud management platform — for centralised configuration, firmware management, and monitoring.

• AES encryption with per-unit unique security certificate
• TLS and SRTP for secure call transmission
• TR-069, HTTP/HTTPS, and TFTP provisioning
• GDMS compatible for free centralised cloud management
• SSH, Telnet, and web UI for local management

Proudly sold by the Ringwood Digital Store.

The HT841/881 FXO gateway series enables businesses of all sizes to create an easy-to-deploy VoIP solution, seamlessly connecting multiple locations and all devices within an office to any hosted or on-premise IP PBX network. The HT841 is the 4-port model in the series — the ideal fit for smaller offices, retail environments, or branch locations with up to four active PSTN or analogue lines that need to remain operational alongside a modern VoIP or IP PBX platform.

Key Highlights

• 4× RJ11 FXO ports and 1× RJ11 FXS port
• Supports 3 SIP profiles across the FXS and FXO ports
• 2× 10/100/1000 Mbps RJ45 ports — one with 802.3af PoE-PD support
• Powered via PoE, optional PoE injector, or optional 12V power supply (sold separately)
• Designed and tested for full interoperability with leading IP PBXs, soft-switches, and SIP-based environments

NAT Router & Lifeline Support

The HT841 includes a high-performance NAT router for basic routing and network edge protection in smaller deployments. Lifeline support hard-relays the FXS port to an FXO port in the event of a power outage, ensuring a connected analogue phone can still make and receive PSTN calls even when power or internet connectivity is disrupted. This is a particularly practical feature for South African deployments where load shedding and connectivity interruptions are real-world concerns.

• Built-in high-performance NAT router for network edge protection
• PSTN lifeline — FXS port hard-relays to FXO port during power outage for emergency call continuity
• Failover SIP server automatically switches to a secondary server if the primary loses connection
• Up to 1000 Mbps in bridge mode; up to 100 Mbps in NAT mode

Fax, Codec & Telephony Feature Support

T.38 fax support enables reliable Fax-over-IP transmission, while broad codec compatibility ensures voice quality across varied VoIP infrastructure. 3-way voice conferencing is supported per port, and a full set of standard telephony features makes the HT841 a capable drop-in gateway for virtually any SIP-based environment.

• T.38 Fax-over-IP with automatic G.711 pass-through fallback
• G.711, G.723.1, G.729, G.726-32, iLBC, and Opus codec support
• 3-way voice conferencing per port
• Caller ID, call waiting, call transfer, call forward, and do not disturb
• Flexible dial plans for call routing control

Security & Easy Management

Strong AES encryption with a unique security certificate per unit protects all calls and account credentials. Automated and secure provisioning via TR-069 makes mass deployment straightforward, and the HT841 is fully compatible with GDMS — Grandstream’s free cloud management platform — for centralised configuration, firmware management, and monitoring alongside other Grandstream devices.

• AES encryption with per-unit unique security certificate
• TLS and SRTP for secure call transmission
• TR-069, HTTP/HTTPS, and TFTP provisioning options
• GDMS compatible for free centralised cloud management
• Simple web UI for standalone configuration

Proudly sold by the Ringwood Digital Store.

The HT841/881 FXO gateway series is the ideal solution for businesses of all sizes looking to create an easy-to-deploy VoIP network, seamlessly connecting multiple locations and devices within an office to any hosted or on-premise IP PBX network. The HT881 is the 8-port model in the series, making it well suited to small and medium businesses with multiple active PSTN or Telkom lines that need to remain operational alongside a modern VoIP platform.

Key Highlights

• 8× RJ11 FXO ports and 1× RJ11 FXS port
• Supports 3 SIP profiles across the FXS and FXO ports
• 2× 10/100/1000 Mbps RJ45 ports — one with 802.3af PoE-PD support
• Powered via PoE, optional PoE injector, or optional 12V power supply (sold separately)
• Designed and tested for full interoperability with leading IP PBXs, soft-switches, and SIP-based environments

NAT Router & Lifeline Support

The HT881 includes a high-performance NAT router, providing basic routing and network edge protection without the need for a separate device in smaller deployments. Critically for environments where telephony uptime is essential, lifeline support hard-relays the FXS port to an FXO port in case of a power outage — meaning a connected analogue phone can still make and receive PSTN calls even when power or internet is disrupted. This is a particularly practical feature for South African deployments where load shedding and connectivity interruptions are real-world concerns.

• Built-in high-performance NAT router for edge protection
• PSTN lifeline support — enables calls via the FXS port over PSTN in the event of power or internet outage
• Failover SIP server automatically switches to a secondary server if the primary loses connection
• Up to 1000 Mbps in bridge mode; up to 100 Mbps in NAT mode

Fax, Codec & Telephony Feature Support

T.38 fax support enables reliable Fax-over-IP transmission, while a broad codec selection ensures voice quality and compatibility across different VoIP infrastructure configurations. 3-way voice conferencing is supported per port, adding a useful collaboration capability for small teams using connected analogue handsets.

• T.38 Fax-over-IP for reliable fax transmission over VoIP
• G.711, G.723, G.726, G.729, iLBC and additional codec support
• 3-way voice conferencing per port
• Caller ID, call waiting, call transfer, call forward, and do not disturb
• Flexible dial plans for call routing control

Security & Easy Management

Strong AES encryption with a unique security certificate per unit protects all calls and account credentials. Automated and secure provisioning via TR-069 makes mass deployment straightforward, and the HT881 is compatible with GDMS — Grandstream’s free cloud management platform — for centralised configuration, firmware management, and monitoring alongside other Grandstream devices.

• AES encryption with per-unit unique security certificate
• TLS and SRTP for secure call transmission
• TR-069, HTTP/HTTPS, and TFTP provisioning options
• GDMS compatible for free centralised cloud management
• Simple web UI for standalone configuration

Proudly sold by the Ringwood Digital Store.

The GXW4108 FXO gateway enables businesses of all sizes to create an easy-to-deploy VoIP solution, seamlessly connecting multiple locations and all devices within an office to any hosted or on-premise IP PBX network. For South African businesses still reliant on Telkom PSTN or analogue lines, the GXW4108 is the practical adapter that makes migration to VoIP possible without a full infrastructure overhaul.

Key Highlights

• 8× RJ11 FXO ports for connecting analogue PSTN telephone lines
• Dual 10/100 Mbps RJ45 network ports
• Designed and tested for full interoperability with leading IP PBXs, soft-switches, and SIP-based environments
• Compatible with Grandstream UCM series, FreePBX, Asterisk, and third-party IP PBX platforms

Broad Codec & Fax Support

Voice compression support covers G.711, G.723, G.726 (40/32/24/16kbps), G.729A/B/E, G.728, and iLBC, ensuring compatibility across a wide range of VoIP infrastructure. T.38 compliant Group 3 Fax Relay supports fax transmission up to 14.4kbps, with automatic fallback to G.711 for fax pass-through — meaning existing fax machines connected through PSTN lines continue to work reliably.

• G.711, G.723, G.726, G.729A/B/E, G.728, and iLBC voice codec support
• T.38 compliant fax-over-IP up to 14.4kbps with G.711 fax pass-through fallback
• SIP video support via H.264 codec
• G.168 compliant echo cancellation and dynamic jitter buffer

Reliability & PSTN Failover

PSTN failover on power failure ensures that even when the gateway loses power, PSTN calls can still pass through to analogue phones — a critical feature for businesses where continuous telephony availability is non-negotiable. This lifeline capability provides an added safety net in environments with unreliable power, making it especially relevant for South African deployments where load shedding is a real-world consideration.

• PSTN failover / lifeline on power failure
• G.168 compliant echo cancellation and dynamic jitter buffer for clear voice quality
• Modem detection and auto-switch
• Flexible dial plans for call routing control

Security & Easy Management

Advanced security protection with SRTP encryption protects call content in transit. Provisioning options include TFTP and HTTP for automated mass deployment, and the GXW4108 is compatible with GDMS — Grandstream’s free cloud management platform — for centralised configuration, monitoring, and firmware management alongside other Grandstream devices.

• SRTP encryption for secure voice transmission
• TFTP and HTTP provisioning for automated deployment
• GDMS compatible for free centralised cloud management
• Supports a wide range of caller ID formats
• Web UI and auto-discovery for straightforward initial setup

Proudly sold by the Ringwood Digital Store.