Grandstream pairing/ PTSN line extend

I am pretty new in this domain, so please send my some ideas. I have two PTSN analog phone lines. I wand to extend them, about 2 km via ETH FO line. How to pairing HT 881 ( 2 equipment ) and HT 818 (1 equipment). Any diagram and any advice are welcome. Thank You!

Do you have an Internet connection at both sites? (Broadband speeds or greater.)

Do you have a physical connection over those 2 km, if so you can use as little as one pair of UTP with a ‘ring-down’ like

The 881 has 8 FXO ports; you would only need one of them, unless the PSTN lines are in different locations.

If you don’t have internet (or don’t want to connect these devices to the internet), you should be able to assign static private IP addresses, point the devices at each other and set them to not register. You will need to temporarily connect a PC for configuration; assign a temporary static IP on the same subnet.

Thank you all for the answers! I have connection between this two equipment using static IP. I set SIP server on one of them the other equip (and vice versa). I succeed to call from the PBX side to the subscriber side but I cant perform a dialing from the subscriber side. What I missing in dialing plan?

Without any of your configurations or logs, we will all remain as mystified as you :wink:

As configuration I used official Grandstream manual “Peering-HT8xx-With-HT841_HT881”. In log file my dialing appear normal initiation and closed but no ringing phone.

When I first answered that post, I assumed that you needed to connect the lines to a device with only an analog interface (legacy PBX, key system, alarm system, fax machine, etc.)

To connect remote analog lines to FreePBX, you should use only the HT881, set up to register to a pjsip trunk on FreePBX. This gives you better voice quality, call setup times and reliability (and frees up the 818 for another application or for sale).

Typical trunk settings:

Trunk Name: (same as username on HT)
Secret: (same as SIP password on HT)
Authentication: Both
Registration: Receive
Match Inbound Authentication: Auth Username
Rewrite Contact: Yes