The Grandstream HT813 is a versatile 2-SIP Analog Telephone Adapter (ATA) Gateway that seamlessly bridges traditional analog telephony with modern VoIP networks. Designed for businesses and home users seeking reliable voice communications, this device combines both FXS and FXO ports to connect analog phones and PSTN lines to IP-based systems.
The Grandstream HT813 provides an ideal solution for businesses transitioning to VoIP while maintaining existing analog equipment investments. The FXS port allows you to connect traditional analog phones or fax machines, while the FXO port with lifeline support ensures continuity by maintaining a connection to the PSTN line during power or network outages. This dual functionality makes it particularly valuable for organizations requiring backup communication capabilities or those operating in hybrid telephony environments. Small businesses, remote offices, and home users will appreciate the device's straightforward deployment and robust feature set that rivals traditional phone systems.
When you choose this Grandstream HT813 ATA Gateway, you're making a smart investment in reliable communication technology backed by a company with over 30 years of industry expertise. Every unit passes our extensive refurbishing and upgrade process, ensuring you receive a fully functional device that meets the highest standards of performance and reliability.
We stand behind every product we sell with comprehensive warranty coverage and a satisfaction guarantee. Whether you're upgrading your business phone system or setting up remote office connectivity, you can purchase with confidence knowing you're getting quality equipment at a competitive price.

These products are brand new and have never been used. They arrive in the original manufacturer packaging in pristine, factory-fresh condition.
| Manufacturer | Grandstream |
|---|---|
| Model | HT813 |
| Networking Interfaces | 2x 10/100Mbps ports (RJ45) with integrated NAT router |
| # of Telephone Interfaces | 1x RJ11 FXS port 1x RJ11 FXO PSTN line port with lifeline support |
| Voice Compression | G.711 with Annex I (PLC) and Annex II (VAD/CNG), G.723.1, G.729A/B, G.726-32, iLBC, and Opus |
| Fax Support | T.38 Fax for reliable Fax-over-IP; T.38 compliant Group 3 Fax Relay up to 14.4kpbs and auto-switch to G.711 for Fax Pass-through |
| Telephony Features | Caller ID display or block, call waiting, flash, blind or attended transfer, forward, hold, do not disturb, and 3-way conference |
| Provisioning | HTTP, HTTPS, TFTP, SSH, TR-069, and secure automated provisioning using AES encryption |
| Security | TLS/SIPS/HTTPS for Control, SRTP for Media, and strong AES encryption with a security certificate per unit |
| Dimensions (WxDxH) | 5.14" x 3.56" x 1.14" |
| Mounting | Desktop |
| Included | 1x HT813 Analog Telephone Adapter Unit 1x Universal Power Adapter 1x Ethernet Cable 1x Quick Installation Guide 1x GPL Statement/License |
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