The following FAQ provides a clear and structured overview of the Grandstream HT801/HT802/HT812/HT814/HT818 ATA series. It covers essential topics including installation, SIP configuration, device management, networking behavior, security, and troubleshooting. Each question is designed to help users quickly understand and operate the HT8xx family with confidence and accuracy.
Product Overview & Hardware Basics
The HT801 is a single-port FXS ATA, while the HT802 provides two FXS ports. The HT812 and HT814 offer dual Gigabit LAN/WAN ports and 2 or 4 FXS ports, this allow them to function as small VoIP routers with integrated NAT and DHCP server capabilities. The HT818 is the largest model, and offers 8 FXS ports and a full Gigabit WAN/LAN router, making it suitable for multi-phone office deployments requiring centralized analog-to-VoIP migration. All devices provide the same SIP feature set, security options, provisioning methods, and core telephony capabilities. Every model supports two SIP profiles, except the HT801 and HT802, which support one and two FXS-port configurations respectively.
All models use LED indicators for quick diagnostics:
- Power LED – Solid when powered, flashing during boot.
- WAN/LAN LEDs – ON when link is active; blinking indicates network activity.
- Phone LEDs (per FXS port):
- OFF: Not registered
- Solid Blue: Registered and idle
- Slow Blink: Voicemail waiting
- Fast Blink: Off-hook or active call
The HT818 includes LEDs for Phone1–Phone8, providing easy visibility for multi-port use.
Each FXS port connects to any standard analog touch-tone phone, fax machine, or PBX analog extension using an RJ11 cable. The HT818 has eight FXS ports, HT814 has four, HT812 has two, HT802 has two, and HT801 has one. Each port can be independently assigned its own SIP User ID and authentication credentials, this allows the registration of multiple accounts or extensions on a single device.
Analog device load is measured in REN (Ringer Equivalence Number). Maximum REN and wiring distance vary:
- HT801: Up to 5 REN, 1 km on 24 AWG cable
- HT802: 2 REN, 1 km
- HT812: 3 REN, 1 km
- HT814: 2 REN, 1 km
- HT818: 2 REN, 1 km for each FXS port
These limits determine how many analog phones can be daisy-chained and how far they can be extended from the ATA.
HT801/HT802: 5V DC, 1A
HT812: 12V, 0.5A
HT814: 12V, 1A
HT818: 12V, 1.5A
Always use the original power adapter, as incorrect voltage may cause boot loops, audio distortion, or irreversible hardware damage.
Yes, all models upport global Caller ID standards such as Bellcore Type I & II, ETSI, BT, NTT, and DTMF-based CID. This ensures compatibility with most analog handsets regardless of region and guarantees proper CID delivery during SIP-to-analog translation.
All models fully support T.38 Fax Relay (Group 3 up to 14.4 kbps) and can automatically switch to G.711 pass-through when needed. This dual-mode handling improves reliability depending on network quality and provider capabilities.
Security is consistent across models and includes:
- TLS, SIPS, HTTPS for signaling security
- SRTP for encrypted media
- AES-encrypted configuration files
- SSH access, secure admin login
- Failover SIP server for service continuity
- Per-unit certificates (notably HT812/HT814/HT818)
These protections safeguard SIP credentials, configuration downloads, and active calls.
GR-909 diagnostics allow the ATA to test analog line conditions internally, including:
- Foreign voltage detection
- REN overload
- Long/short circuit checks
- Wiring issues
The HT801/802, HT812/814, and HT818 all support GR-909 tests, providing valuable troubleshooting without test equipment.
All models include a rear reset button. Pressing it for 7 seconds restores factory settings, removing SIP accounts, passwords, provisioning data, network configurations, and any custom settings. The HT8xx V1 devices also include three reset modes when performed via Web UI (Full Reset, ISP Data, VoIP Data). Resetting should be done only when necessary, as recovery requires full reconfiguration.
Installation & Initial Setup
Each ATA model includes the unit itself, a correctly rated power adapter, an Ethernet cable, and a quick installation guide. For HT801/HT802, the package contains the ATA, a 5V–1A PSU, and an Ethernet cable. For HT812/HT814 and HT818, the contents include the ATA, a 12V PSU, and an Ethernet cable needed to connect phones and network devices. All manuals instruct users to check the package contents before installation and to contact the system administrator if anything is missing.
To set up either model, connect an analog phone to the FXS port using an RJ11 cable. Connect the Internet port to a router or modem using an Ethernet RJ45 cable. Finally, power on the device using the included PSU (5V–1A). When the Power, Ethernet, and Phone LEDs turn solid, the ATA is operational and ready to register. Both models obtain their IP address from the DHCP server by default.
These models are installed similarly to HT801/802 but include dual Gigabit WAN/LAN ports. Connect phones to the FXS ports, connect WAN to your router/switch, optionally connect the LAN port to a PC or secondary device, and power on the ATA. Their built-in NAT router allows devices on the LAN port to share internet connectivity. LEDs for Power, WAN, and Phone ports must turn solid to indicate the device is in idle state.
When connected using the WAN port, the HT81x works as a DHCP client.
Steps:
- Connect analog phones to Phone 1–8 ports.
- Connect WAN to your router/switch/modem.
- Power the device using the 12V–1.5A PSU.
Once ready, the Power, WAN, and Phone LEDs become solid. This method is ideal when another device (router/firewall) already manages the network.
When using the LAN port, the HT81x provides DHCP addresses to connected devices.
Steps:
Power on the device and ensure NAT Router mode is enabled under Basic Settings → Device Mode.
In this mode, devices receive IP addresses in the default 192.168.2.x range assigned by the HT81x.
Connect phones to FXS ports.
Connect a PC or switch to the ATA’s LAN port.
Across all models, LEDs provide clear operational status:
- Power LED → Solid when powered; blinking during boot.
- WAN/Ethernet LED → Solid when connected; flashing during activity.
- Phone LEDs →
- OFF = Unregistered
- Solid = Registered
- Fast Blink = Off-hook/Busy
- Slow Blink = Voicemail waiting
HT818 includes additional LEDs for each of its 8 FXS ports, plus separate WAN and LAN LEDs.
All HT8xx models share the same IVR method:
- Pick up the handset.
- Dial *** (three stars).
- When prompted, press 02.
The device will announce the current IP address.
This works whether the device is using DHCP, Static IP, or PPPoE mode, just make sure the analog phone is connected to the ATA with an RJ11 cable.
For HT812/814/818, WAN web access is disabled by default when using a public IP. To enable it:
- Access IVR → ***
- Press 12
- Press 9 to enable WAN Web Access
- Reboot the unit
After rebooting, type the ATA’s IP address in a browser to access the Web UI.
When using the LAN port:
- Connect your PC to the ATA LAN port.
- Your computer will receive an IP address from the ATA (default range 192.168.2.x).
- Access http://192.168.2.1
in your browser.
Log in using administrator credentials.
This method is especially useful when WAN access is blocked or disabled.
All HT8xx models support three user levels:
- Admin → username: admin, password: admin (must be changed at first login)
- User → username: user, password: 123
- Viewer → username: viewer, password: viewer
User and Viewer levels are disabled by default and need to be enabled via Advanced Settings.
Using the IVR (***):
- Dial 01 → Press 9 to toggle between DHCP, Static IP, and PPPoE.
- For Static IP, configure IP, Subnet, Gateway, and DNS using codes 02–05.
- PPPoE credentials must be configured through the Web GUI.
A reboot is required after making network-related changes.
All HT8xx devices use a similar SIP configuration flow:
- Log in to Web UI.
- Go to Profile (HT812/814/818) or FXS Port pages (HT801/802).
- Enter:
- SIP Server
- Outbound Proxy (optional)
- Failover SIP Server (optional)
- Configure each FXS port with:
- SIP User ID
- Authenticate ID
- Authenticate Password
- Display Name
- Set Account Active = Yes and Enable Port = Yes.
Registration status appears under Status → Port Status → Registration.
IVR, Web Interface & Device Management
The IVR (Interactive Voice Response) menu allows administrators to perform key configuration actions without accessing the web interface. By dialing *** on any phone connected to an FXS port, the ATA reads out network information, allows changing IP modes (DHCP, Static, PPPoE), configuring firmware/config server addresses, checking MAC address, enabling WAN access, initiating firmware upgrades, triggering direct IP calls, and performing factory reset operations. The IVR is available across all HT8xx devices and provides a fallback when web access is not available.
Pick up the handset of any phone connected to an FXS port and dial ***. When you hear “Enter a menu option,” press 02 to have the IP address announced. If the device is in Static IP mode, you can use the IVR to set the address manually by entering a 12-digit numeric string (e.g., 192168000026).
Network configuration via IVR includes:
- 01 → Switch between DHCP / Static / PPPoE
- 02–05 → Configure Static IP, Subnet, Gateway, DNS
- 10 → Announce MAC address
- 12 → Enable/Disable WAN Web Access
These options allow full basic network configuration even without GUI access.
There are three login roles across the HT801/802/812/814/818 series:
- Admin → username: admin, password: admin (full access)
- User → username: user, password: 123 (Status & Basic Settings)
- Viewer → username: viewer, password: viewer (read-only mode)
User and Viewer roles are disabled by default and can be enabled under Advanced Settings. On first login, the admin password must be changed and must contain uppercase, lowercase, and numeric characters.
On HT812/HT814/HT818, WAN Web Access is disabled for security when using a public IP. To enable it:
- Dial *** on a connected phone.
- Press 12.
- Press 9 to toggle WAN access to “enabled”.
- Reboot the device.
After reboot, entering the device’s WAN IP in a browser will allow login.
When changing settings from the web interface:
- Update saves changes without applying them.
- Apply saves and applies the changes immediately.
Some modifications, especially network mode, SIP profile parameters, provisioning changes, and FXS port parameters, require a reboot for full effect.
Accessible from the Web UI under Basic Settings → Web Port, you can set any port between 1 and 65535. After clicking Apply, the ATA will serve its Web GUI via the new port. On HT818, this setting is also available and follows the same behavior.
There are three reset methods across HT801/802/812/814/818:
- Hardware button → Press reset hole for ~7 seconds (HT818 requires unplugging Ethernet first).
- IVR reset → Dial *** → 99 → enter encoded MAC address.
- Web UI reset → Available under Basic settings.
A factory reset deletes all account, network, and provisioning data, returning the ATA to default state.
The IVR requires entering the MAC using a T9-style mapping:
- Digits 0–9 are entered normally.
- A = 22, B = 222, C = 2222
- D = 33, E = 333, F = 3333
Example: 000b8200e395 becomes 0002228200333395.
This encoded number must be entered after selecting menu option 99.
All HT8xx models support:
- HTTP/HTTPS, TFTP, FTP/FTPS
- SSH, Telnet, SNMP, TR-069
- Syslog for remote logging
HT812/814/818 include per-unit security certificates and support provisioning and firmware management through cloud platforms such as GDMS, as well as local or remote provisioning servers.
Yes. The entire HT8xx family, including HT801/802, HT812/814, and HT818, can be provisioned, monitored, and managed through Grandstream Device Management System (GDMS). GDMS allows centralized upgrades, configuration file delivery, monitoring, and troubleshooting for fleets of ATAs across multiple sites. This is especially useful for service providers or enterprises deploying many HT8xx units.
SIP Configuration, Call Features & Telephony Behavior
All HT8xx devices allow:
- Primary + Failover SIP Server
- Automatic failover when the main server is unreachable
- Automatic re-registration when the primary server becomes available
- Preference control (“Prefer Primary SIP Server”)
This ensures continuity during SIP server outages or ISP routing issues.
Direct IP calling allows you to call another VoIP device without a SIP server.
Two methods:
- IVR Method → Dial *** → 47 → enter IP address (using * instead of dots).
- Star Method → Dial *47 + target IP.
Example:
To call 192.168.0.160 → dial *47 192*168*0*160.
Used mainly for testing or internal LAN communication.
All HT8xx models use the same process:
- Log in to the Web GUI.
- Go to Profile (for HT812/814/818) or FXS Port (1–8) (HT801/802/818).
- Set Account Active = Yes.
- Enter Primary SIP Server, Outbound Proxy, and optional Failover SIP Server.
- Under FXS Port settings, enter:
- SIP User ID
- Authenticate ID
- Authenticate Password
- Display Name
- Click Apply and reboot if required.
Registration status appears under Status → Port Status → Registration.
All HT8xx ATAs support SIP over:
- UDP,
- TCP, and
- TLS (secure SIP transport).
Media encryption is supported via SRTP, and the devices also support IMS/3GPP environments. This ensures compatibility with modern VoIP platforms requiring secure SIP signaling and encrypted RTP streams.
Across all models, supported codecs include:
- G.711 μ-law / A-law
- G.722 (HD audio)
- G.723.1
- G.729 A/B
- G.726-32
- iLBC
- Opus
They also include advanced features like dynamic jitter buffer, PLC, VAD/CNG, and robust echo cancellation.
For the HT801/HT802, you can set the codec priority within each FXS port’s configuration page. For the HT812/HT814/HT818, codec order is configured under each SIP profile. Simply drag or select codecs to arrange them in your preferred sequence (e.g., G.722 → PCMU → G.729).
You can also temporarily change the preferred vocoder through the IVR menu by selecting option 07, then cycling through the available codecs using the 9 key.
The HT8xx series supports:
- In-audio DTMF
- RFC2833 (RTP Event)
- SIP INFO
Most SIP servers prefer RFC2833, and it should be used unless the provider explicitly requires in-band or SIP INFO. Users can configure a priority list under each FXS port.
Supported features include:
- Call waiting
- Blind and attended call transfer
- 3-way conferencing
- Call hold / resume
- Caller ID block/unblock
- Inter-port calling (HT802/HT818)
- Do Not Disturb (DND)
- Paging
- Call forwarding (unconditional, busy, delayed)
These features mirror traditional analog PBX functions and are controlled either through star codes or Web UI parameters.
Some key examples:
- *69 → Call return
- *72 / *73 → Enable/disable unconditional call forward
- *50 / *51 → Disable/Enable call waiting
- *67 / *82 → Block/unblock caller ID per call
- *30 / *31 → Block/unblock caller permanently
- *87 → Blind transfer
- *90 / *91 → Busy call forward on/off
- *92 / *93 → Delayed call forward on/off
These codes work on all HT8xx devices unless overridden by the service provider.
Yes — all models support Bellcore 3-way conference:
- Put the first call on hold using FLASH.
- Dial the second number.
- When answered, press FLASH + 3 again to merge the calls into a 3-way confernce.
HT8xx devices can also drop or transfer calls during conference depending on configuration.
You can call another port on the same ATA without SIP registration using:
- Dial ***7X
Where X is the port number.
Example: On HT802, calling the phone on port 1 → ***71.
This is useful during testing or when using the ATA as a standalone analog-to-analog communication unit.
The HT8xx devices support:
- T.38 Fax Relay (G3 up to 14.4 kbps)
- Automatic fallback to G.711 pass-through
Fax success depends on network stability, provider support, and proper jitter buffer settings. The HT801/802/812/814/818 all include T.38 configuration under each FXS port.
Firmware Upgrade, Provisioning & Security
All HT8xx ATAs (HT801/802/812/814/818) support firmware upgrades using:
- TFTP
- HTTP / HTTPS (default)
- FTP / FTPS
Users can specify the Firmware Server Path as either an IP address or a fully qualified domain name. Upgrades can occur automatically on boot, on schedule, or when triggered manually through the Web UI, IVR, or SIP NOTIFY resync commands.
To upgrade via the Web interface:
- Log into the ATA Web GUI.
- Navigate to Advanced Settings → Firmware Upgrade and Provisioning.
- Enter the URL/FQDN or IP of the firmware server.
- Select the desired upgrade protocol (TFTP/FTP/FTPS/HTTP/HTTPS).
- Set Always Check for New Firmware if automatic checks are needed.
- Click Apply, then Reboot.
Once the device restarts, it will download and apply the firmware file automatically.
Yes. Users can download firmware from Grandstream’s website, unzip the file, and upload it directly through the Web UI:
- Go to Advanced Settings → Firmware Upgrade.
- Select Upload Firmware.
- Browse to the file (e.g., HT802fw.bin).
- Upload and wait for the device to reboot.
This method is convenient when no provisioning or remote server is used.
Yes. All HT80x and HT81x devices support event:resync SIP NOTIFY.
A provisioning server can send a NOTIFY containing:
Event: resyncWhen received, the ATA checks its provisioning server and downloads new firmware/config files if updates exist. This allows remote, automated upgrades without user intervention.
Supported provisioning methods include:
- TFTP, HTTP, HTTPS, FTP, FTPS
- TR-069 auto-provisioning
- XML configuration files (encrypted or unencrypted)
- AES-encrypted config files
- Zero Configuration with Grandstream UCM
- Cloud management via GDMS
These tools allow mass deployment across enterprise or service provider environments.
When booting or resyncing, the device requests:
- cfg<MAC>.xml
- cfg<MAC> (binary)
If neither exists, it attempts: - cfg<Model>.xml
- cfg.xml
If DHCP Option 67 (bootfile) is provided, the custom filename is downloaded first before falling back to cfg<MAC>.xml.
Example MAC: 000b820102ab → cfg000b820102ab.xml
The ATA can restrict which files it downloads by comparing the server file names to defined prefixes and postfixes.
If the option Check New Firmware Only When Pre/Suffix Changes is enabled, the device will only download new firmware when the file prefix/postfix differs from the previous version.
This allows providers to keep multiple file versions in one directory.
Using the “Automatic Upgrade” settings, the device can perform periodic checks:
- Every X minutes
- Daily at a specified hour
- Weekly on a specified day
This schedule can be staggered across devices by using different intervals so that provisioning servers are not overloaded during mass downloads.
All HT8xx devices support:
- TR-069 for full remote provisioning
- HTTPS Web GUI
- SSH and Telnet
- SNMP
- Syslog (local or remote)
- GDMS cloud platform
TR-069, in particular, allows automated mass deployment with monitoring and remote reboot/update capabilities.
Security mechanisms include:
- TLS/SIPS for encrypted SIP signaling
- SRTP for encrypted RTP media
- HTTPS for secure Web UI access
- SSH for encrypted command-line access
- AES-encrypted configuration files
- Per-device certificates on HT812/ HT814 / HT818
These combined layers secure provisioning, web access, SIP credentials, call media, and system logs.
If the device cannot retrieve firmware:
- It retries according to its upgrade schedule.
- It remains on the current firmware with no service interruption.
- If a failover Config Server Path is configured, it attempts the secondary server.
Upgrades occur only when a valid firmware image is detected.
Yes. With HTTPS, FTPS, and TLS-enabled SIP/Provisioning, the ATAs can be securely deployed on public or untrusted networks. The HT812/814/818 further enhance this with strong AES configuration encryption and individual device certificates, this helps prevent unauthorized provisioning or configuration tampering.
Networking, Dial Plan & Troubleshooting
All HT8xx devices support up to 1 km of 24 AWG wiring on each FXS port.
REN (Ringer Equivalence Number) indicates how many analog phones can ring simultaneously:
- HT801 → 5 REN
- HT802 → 2 REN
- HT812 → 3 REN
- HT814 → 2 REN
- HT818 → 2 REN
Higher REN means more analog devices can be attached without loading the port.
All HT8xx models support a wide range of networking protocols required for VoIP and provisioning, including TCP/IP/UDP, RTP/RTCP, HTTP/HTTPS, DNS, DHCP, NTP, TFTP, SSH, Telnet, STUN, SNMP, and TR-069. Layer-2/Layer-3 QoS is also supported via 802.1Q VLAN, 802.1p priority, DiffServ, and ToS tagging. These protocols ensure compatibility with enterprise-class VoIP systems and secure provisioning environments.
If the ATA is installed behind NAT:
- Configure a STUN Server in Advanced Settings.
- Set Use Random SIP/RTP Ports to Yes (recommended when multiple devices share the same network).
- Under each FXS port, set NAT Traversal = Yes.
If the ATA uses a public IP, STUN should be disabled and random port usage should be set to No.
Dial plans define what patterns of digits are valid and when calls should be sent to the SIP server. They ensure correct number matching, prevent misdials, and create custom calling rules. Dial plans are fully customizable under FXS ports. Users can define digit lengths, prefixes, number blocking, and more. HT8xx devices also support the use of # as a send key, reducing wait time after dialing.
By default, the ATA uses a 4-second “No Key Entry Timeout” when the user finishes dialing. If the option Use # as Dial Key is enabled, pressing # immediately sends the dialed digits to the SIP server without waiting. This improves user experience and eliminates delays when placing calls.
GR-909 testing diagnoses analog line conditions without external tools. The ATA evaluates:
- Foreign voltage
- Tip/Ring short or open
- REN overload
- Impedance and wiring faults
This is especially useful when troubleshooting wiring issues, faulty phones, or environmental line problems before blaming SIP configuration.
Troubleshooting steps include:
- Verify network mode (DHCP/Static) and check IP using IVR option 02.
- Ensure DNS server settings are correct (Static mode requires manual DNS entry).
- Confirm SIP User ID, Authenticate ID, and Password.
- Check if the SIP server address is reachable.
- If behind NAT, enable STUN or adjust NAT traversal options.
- Ensure the FXS port is set to Account Active = Yes and Enable Port = Yes.
Registration status appears under Status → Port Status.
WAN Web Access is disabled by default when the ATA detects a public IP. To enable it:
- Dial *** → 12 → press 9
- Reboot the ATA
After enabling, WAN access works normally unless blocked by external firewalls.
Check the following:
- Verify the FXS port LED is solid (registered).
- If unregistered, the ATA still provides default dial tone, unless Play Busy Tone When Unregistered is enabled.
- Confirm Outgoing Call Without Registration is set appropriately (NO means calls cannot be made until registered).
- Verify SIP account credentials.
Troubleshooting checklist:
- Check codec compatibility between ATA and SIP provider.
- Verify DTMF mode matches SIP server requirements.
- Confirm dial plan is not blocking the number.
- Ensure network is stable and QoS is configured.
- Use IVR → 47 to test Direct IP Calling for local connectivity tests.
- Check whether the SIP server is reachable from the ATA’s network.
Common causes include NAT and codec issues. Solutions:
- Enable STUN and NAT Traversal if behind a router.
- Set Use Random SIP/RTP Ports to YES.
- Ensure firewall rules allow RTP streams.
- Avoid using symmetric RTP unless required by the service provider.
- Confirm matching codecs between ATA and SIP receiver.
Reboot when:
- Network settings are changed
- SIP server or routing behavior needs refreshing
- Firmware upgrade is applied
Factory Reset when:
- Login credentials are lost
- Provisioning requires a fresh device state
- Severe misconfiguration prevents normal operation
Factory reset restores all settings to default and deletes SIP accounts, passwords, network settings, and provisioning details.