Learning Hub / Tutorials / ATA Configs / Grandstream HT801 to Hosted 3CXFAQs

Tutorials: Grandstream HT801 to Hosted 3CX

Step : Overview

This method no longer works with the newer 3CX systems (V18+). An SBC is required for faxing to work properly.

In this guide we will show you how to connect your Grandstream ATA to a cloud/hosted instance of 3CX. This method will use G.711 as your faxing method which is supported on Voxtelesys SIP.

Note: for fax machines over SIP it is recommended to lower the BAUD rate on the fax machine. Try BAUD rate at 9600 bps or even lower at 7200 bps.

Step : Log in to ATA Device

Go under Grandstream Device Configuration and log in. If you do not know the IP address of the ATA, you can plug in an analog phone and dial ***02 and it will play back the IP address.

Step : Select FXS Port

Under Grandstream Device Configuration, select "FXS Port"

Step : Fill in Data

Primary SIP Server: Your 3CX IP address. It must be a static IP address.
SIP User ID: 3CX Extension number.
Authentication ID: 3CX ID.
Authentication Password: 3CX Password.

3CX ID and Password can be found under the extension > Phone Provisioning

Enter in Grandstream ATA/GUI:

Step : Fill in Data (continued)

Codecs:

Preferred Vocoder (in listed order):

choice 1: PCMU
choice 2: PCMA
choice 3: G729

Enable Feature Settings:

Fax Mode ("T.38" selected): The options are T.38 and Pass-Through.
Re-INVITE After Fax Tone Detected ("Enabled" selected): The options are Enabled and Disabled.