Grandstream HT80x V2 Setup Guide for Power-T.38 SIP Trunks (HT801 V2

Connect your Grandstream HT80x V2 series ATA (HT801 V2 | HT802 V2) to our fax-optimized Power-T.38 SIP trunking service for reliable faxing over SIP.

Grandstream’s Analog Telephone Adapters (ATAs) offers a ton of features at an affordable price point. They are trusted and deployed by some of the world's largest service providers. This article will address the configuration of the 2-port HT802 V2, but the configuration will be the same with the 1-port version of this device.

The HT801 V2 is a 1-port FXS, with 10/100 Mbps ethernet and no router. It supports one SIP account.

The HT802 V2 is a 2-port FXS, with 10/100 Mbps ethernet and no router. It supports up to two SIP accounts.

⚠️ Before You Buy an HT802 V2 ⚠️

We recommend upgrading to the HT81X V2 series (HT 812 V2 | HT814 V2 | HT818 V2) whenever you need to connect more than one analog fax device to a Grandstream ATA. The HT802 V2 does support two analog fax devices, but it only supports one fax machine per SIP trunk. This means if you’re directly connecting to T38Fax and want to use both fax ports on your ATA, you will have to provision (and pay for) two Power-T.38 trunks instead of one. The HT812 V2 can service both fax ports with a single Power-T.38 trunk, and can route incoming calls to a specific FXS port based on the called number (incoming DID). Thus, we consider it the more versatile option.

Prerequisites

This article assumes:

You have signed up for a free trial of our Power-T.38 SIP trunking service
You have access to our customer self-care portal with an assigned role that allows you to add and delete SIP trunks
You have used the T38Fax self-care portal to create a registration-authenticated SIP trunk not used by another device. We will connect the ATA to this trunk in this guide
You have connected your ATA to your network and can login via the web interface
You have an analog fax device connected to an FXS port on the ATA

Firmware

Update to the latest firmware for your HandyTone before connecting to our service. T38Fax recommends you use firmware version 1.0.5.4 or later.

You can download the current production release from the Grandstream Firmware page. This page includes firmware downloads for all of Grandstream’s products. You will have to find your ATA model’s firmware download link on this page. You can Ctrl+F for “HT801 V2” or “HT802 V2” to find it. Please be careful to only download V2 firmware for this new generation of Grandstream ATAs. The stable release firmware download link is in the second column. Once this file has downloaded, unzipping it will extract a .bin file. You will upload the .bin file to the ATA.

In the ATA’s web interface, navigate and expand "Maintenance" on the left hand side and click on the "Upgrade" option. On the Upgrade page, click the Upload button under "Upgrade via Manually Upload" and select the file downloaded from Grandstream's website; the device will start the upgrade process and will then restart. Once the restart is complete, you will login again.

Web Configuration

On the left sidebar, expand Port Settings and select FXS PORT1. Each following subsection refers to a different tab in the top menu bar. The blue highlighted tab “General Settings” will automatically be selected by default.

On an HT802 V2, you can repeat these steps for FXS PORT2 to connect the second port to a second trunk. Do not connect FXS PORT2 to the same trunk as FXS PORT1.

General Settings

Configure the following information in General Settings:

Primary SIP Server: sip.t38fax.com:5080 ⓘ
SIP User ID: SIP Username ⓘ
Authenticate Password: SIP Password (will be blanked out when saved) ⓘ

Scroll down under the Network Settings and select Keep-Alive in the NAT Traversal drop down.

Once you have entered in all the required information click on the “Save and Apply” button at the bottom.

SIP Settings

Click on SIP Settings and configure the following options in the SIP Basic Settings section:

Register Expiration: 5
Enable SIP OPTIONS/NOTIFY Keep Alive: OPTIONS
Local SIP Port: 5080 ⓘ–If you have more than one device at a site, each device at a site should have a unique port, such as 5081, 5082, etc.

In the same section, scroll down and make the following changes, then click on Save and Apply:

Use Privacy Header: No
Use P-Preferred-Identity Header: No
Use P-Access-Network-Info Header: ❌ (uncheck)
Use P-Emergency-Info Header: ❌ (uncheck)

This will remove about 200 bytes of unused headers from your SIP message. If SIP messages become too large, they must be fragmented across multiple packets. Some firewalls will block packet fragments by default.

Codec Settings

Make the following changes to the Vocoder Settings in the Codec Settings section, then click on Save and Apply:

Change all drop downs to only use PCMU

Scroll down in Vocoder settings and change the following options:

Fax Mode: T.38
T.38 Max Bit Rate: 14400bps
Jitter Buffer Type: Fixed
Jitter Buffer Length: High

Analog Signal Line Configuration

In the Analog Signal Line Configuration section make the following change, then click on Save and Apply:

Disable Line Echo Canceller (LEC): ✅(check)

Call Settings

Scroll down to the General section and uncheck the box for the following options, then click on Save and Apply:

Enable-Call-Waiting: ❌ (uncheck)
Enable-Call-Waiting-Caller-ID: ❌ (uncheck)
Enable-Call-Waiting-Tone: ❌ (uncheck)

Call-Waiting, if enabled, will cause the ATA not to return an immediate busy signal if there’s already a call in progress; it will instead allow the incoming call to ring while playing an occasional audio alert to the end user. This will interfere with the in-progress fax call.

Advanced Settings

In the Security Settings section make the following changes and then click Save and Apply:

Allow Incoming Packets from SIP Proxy Only: ✅(check)

This security feature ensures your ATA only accepts inbound calls from T38Fax.

Call Features Settings

In the Call Features Settings tab, make the following change and then click Save and Apply:

Enable Local Call Features: No

Call features allow end users to configure the ATA using feature codes through the fax machine or a handset. They try this, for instance, if they want to set up a call forward without contacting support. This will not work, however, and end users may not know how to revert the change. We recommend disabling this feature to prevent this scenario. If you need to forward your number to another destination, we recommend doing so through the T38Fax Self-Care Portal.

Fax Device Configuration

Finally, configure your analog fax device to work properly with the ATA and your Power-T.38 SIP Trunk. Review our Recommended Fax Machine Settings for details.

Test, Test, and Test Again

Early and extensive testing will ensure a successful deployment and high rates of user adoption and satisfaction over the long term. We encourage you, therefore, to establish a baseline of successful faxing by testing everything you may have configured above, fixing any errors you find, and escalating any problems you can’t solve yourself to our support team.

Not quite sure how to test? Don’t worry, we’ve got your back. We outline our recommended process in this testing support article.

Support and Additional Resources

Customers looking for technical support can open a case via our customer self-care portal, or by using the “Submit a request” button at the bottom of most knowledge base articles.

We talk a bit about our fax-optimized SIP trunks and explain why T38Fax is the best choice for companies who rely on fax transmissions to conduct business in these articles:

Related to

Grandstream HT80x V2 Setup Guide for Power-T.38 SIP Trunks (HT801 V2 | HT802 V2)