FXS or FXO

FreePBX Hardware
1

Hi to everyone,

I’m new in IP PBX and still learning, I want to share the scenario and wanting to know which port will be use, FXS or FXO.

Scenario:

  1. I have at home a PLDT home fibr ONU which provide fiber internet and VOIP.
  2. SIP account cannot be extracted from the PLDT ONU, we just the RJ-11 to the telephone which comes together with it and it gets a dial tone (Plug n Play).
  3. I want to use the VOIP from the PLDT ONU and share it to FreePBX.
  4. I was advice to use Grandstream Hybrid ATA with FXS and FXO Ports (HT813). Still not purchased.
  5. I have already setup FreePBX in VMware Workstation.

Question:

  1. From PLDT ONU RJ-11 cable, where should it be connected in Grandstream HT813, will it be FXS port or FXO port?

Hoping someone can give me a detailed explanation.

Regards to the community!

2

Hello @kae1078 - The RJ11 from the provider mentioned in #2 is the same thing as an analog line from a traditional telco. This is why the phone works when you connect it and you get dial tone.

Now if you want to connect this to an ATA then it would be plugged into the FXO port. The FXO is the equivalent to a normal analog phone. So you would run an Rj11 from the provider to the ATA, and then it would be a SIP connection back to FreePBX VM. This would typically be an IP Auth trunk, so there would be no user/pass, just both devices trusting each others IP.

Keep in mind you will not get the DID called from the analog line. So this needs to be programmed into the ATA, so it matches an inbound router. Or you can simply use the ANY inbound route, and dump all calls into a single inbound route.

Note: FXS provides voltage/dial tone, this is where you would connect a fax or normal analog phone to. That is why this is not what is needed here.

3

The ONU has a built in FXS ATA. (Foreign Exchange Station). As stated above, you need an FXO interface, to complement this.

Note that it is quite likely that the built in ATA is only intended for use with phones directly operated by humans, and may lack any way of informing you that an outgoing call has been answered, or that the remote end has ended a call, in a way that your ATA can reliably detect.

4

"…built in ATA in the ONU is only…

Just trying to make it a bit more clear to the OP, david.

5

Good morning guy, thanks for taking time to answer my question, I think its about time to purchase the GrandStream HT813 and start the journey.

Again thanks for the replies.

6

You mentioned something about DID, will it be a typical configuration for a setup that I wanted?

7

Yes, in the ATA you should program the DID for each FXO port you will use. This way you can have unique inbound routes to handle inbound calls to those ports.

You can also just create a any inbound route on freepbx by leaving the DID field set to a null value. Then this will mean any call from the ATA will be handled by that route. For a simple setup this may be the easiest as well.