| Applies to | Time needed | Version |
|---|---|---|
| Grandstream HT802 v2 (firmware 1.0.5.7 or newer) | About 15 minutes | v1, March 2026 |
Overview
This article shows you how to connect a Grandstream HandyTone HT802 v2 to your RingOffice phone service, so that a regular analog phone or fax machine can make and receive calls. Setup is done through the device’s web page.
The HT802 v2 is a small analog telephone adapter (ATA). It plugs into your internet router with a network cable and provides two standard phone jacks. Each jack can be connected to its own RingOffice line or extension.
The device is powered through a USB Micro-B port (5 V, 1 A), so most phone chargers will work if the original adapter is lost. It supports caller ID, call waiting, three-way calling, call transfer and fax over IP.
Before you begin
Have these items ready before you start. Your SIP account details are in the welcome email RingOffice sent you. If you cannot find them, contact RingOffice Support before continuing.
- A Grandstream HT802 v2 with its power adapter and a network cable.
- Firmware version 1.0.5.7 or newer. You can check the version on the device’s Status page.
- A working internet connection with a free network port on your router.
- An analog phone or fax machine plugged into Phone Port 1.
- Your RingOffice SIP account details (see the table below).
| Detail from RingOffice | Where it goes in the device |
|---|---|
| SIP server address | Primary SIP Server and Outbound Proxy |
| SIP username (extension or account number) | SIP User ID and Authenticate ID |
| SIP password | Authenticate Password |
| Phone number assigned to this line | For reference only |
Step 1: Connect the device and find its IP address
The device gets its address from your router automatically. You can hear that address through the connected phone.
- Plug a network cable from the HT802’s Ethernet port into your router.
- Plug a phone into Phone Port 1, then connect the power adapter.
- Wait about two minutes until the power and network lights stay solid.
- Lift the handset and dial
***(star star star). A voice menu will start. - Dial
02. The device will read its IP address aloud, for example 192.168.1.50. Write it down.
Step 2: Log in to the web page
Use a computer connected to the same network as the HT802.
- Open a web browser and type the IP address you wrote down, for example
http://192.168.1.50. - Enter the username
admin. - Enter the password printed on the label on the bottom of the device. If you or your IT provider changed it, use that password instead.
If the device asks you to set a new password, choose a strong one and keep it somewhere safe.
Step 3: Enter your RingOffice account
These settings connect Phone Port 1 to your RingOffice line. Leave any field not listed here at its default value.
3a. General Settings
Go to FXS Port 1 > General Settings and fill in the fields below, then click Save.
| Setting | Value |
|---|---|
| Account Active | Yes (checked) |
| Primary SIP Server | SIP server address from RingOffice |
| Prefer Primary SIP Server | Yes |
| Outbound Proxy | Same SIP server address |
| SIP User ID | Your RingOffice SIP username |
| Authenticate ID | Same as SIP User ID |
| Authenticate Password | Your RingOffice SIP password |
| Name | Optional label, for example Front Desk |
| DNS Mode | A Record |
| NAT Traversal | Keep-Alive |
3b. SIP Settings
Go to FXS Port 1 > SIP Settings, set the following, then click Save.
| Setting | Value | Why |
|---|---|---|
| SIP Registration | Yes | Keeps the line signed in to RingOffice |
| Register Expiration | 5 minutes | Re-registers often so incoming calls are not missed behind a router |
| Enable SIP OPTIONS Keep Alive | Yes | Keeps the router connection open between calls |
| Local SIP Port | 5060 | Use 5062 for Port 2, and a different port on any second adapter |
| Check SIP User ID for incoming INVITE | Yes | Rejects calls not addressed to this line |
| Allow incoming SIP messages from SIP proxy only | Yes | Blocks unwanted “ghost” calls from the internet |
3c. Codec Settings
Go to FXS Port 1 > Codec Settings and set the voice codec order to PCMU (G.711 μ-law) first, then G.722, then PCMA. Click Save and Apply.
Step 4: Fax machine settings
Skip this step if the port is used for a regular phone. Fax machines are sensitive to interruptions, so these settings turn off features that can break a fax mid-transmission.
4a. Call Features
Under FXS Port 1 > Call Features:
| Setting | Value |
|---|---|
| Enable Local Call Features | No |
| Enable Call Waiting | No (unchecked) |
| Enable Call Waiting Caller ID | No (unchecked) |
| Enable Call Waiting Tone | No (unchecked) |
4b. Codec Settings
Under FXS Port 1 > Codec Settings:
| Setting | Value |
|---|---|
| Fax Mode | T.38, unless RingOffice Support advises Pass-Through |
| T.38 Max Bit Rate | 14400 bps |
| Jitter Buffer Type | Fixed |
| Jitter Buffer Length | High |
Under FXS Port 1 > Advanced Settings, make sure Enable Line Echo Canceller (LEC) is checked. Click Save and Apply.
Step 5: Test your line
Restart the device so all settings take effect, then confirm the line works in both directions.
- In the web page, click Reboot (top right) and wait about two minutes.
- Log back in and open the Status page. Next to Port 1, Registration should show Registered.
- Lift the phone and listen for a dial tone.
- Call your mobile phone. Check that both sides can hear each other clearly.
- Call your RingOffice number from your mobile. Check that the phone rings and that caller ID appears.
- If a fax is connected, send a one-page test fax to a known working fax number.
Troubleshooting
Most problems come from a typing error in the account details or from the router. Check the matching row below before contacting support.
| What you see | Likely cause | What to try |
|---|---|---|
| No dial tone | Port not registered, or phone cord in the wrong jack | Check the Status page shows Registered. Confirm the phone is in Phone Port 1. |
| Status shows Not Registered | Wrong server, username or password | Re-enter the details from Step 3 exactly as RingOffice provided them. Passwords are case-sensitive. |
| Outgoing calls work, but incoming calls do not ring | Router closing the connection | Confirm NAT Traversal is Keep-Alive and Register Expiration is 5 minutes. |
| One-way audio or no audio | Router SIP ALG interfering with calls | Turn off SIP ALG in your router settings, then restart the router and the HT802. |
| Choppy or robotic voice | Internet connection busy or unstable | Test while no large downloads or video streams are running. Use a wired connection to the router. |
| Fax fails or stops partway | Fax settings not applied | Repeat Step 4. Ask RingOffice Support whether T.38 or Pass-Through suits your line. |
| Forgot the device password | Password changed and lost | Hold the pinhole reset button on the back for 10 seconds to restore factory settings, then start again from Step 1. |
Getting help
If your line still does not work after these steps, submit a ticket to RingOffice Support and include:
- Your company name and the phone number of the affected line.
- The device model (HT802 v2) and its firmware version from the Status page.
- What happens when you try to call, and the time of a recent failed call.
- A screenshot of the Status page.
For more detail on the device itself, see Grandstream’s HT802 v2 Quick Installation Guide and Administration Guide. Firmware is available from the Grandstream firmware site.
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