External FXO Device Advice

I have a FreePBX server running in my house, currently with a couple of PCI FXO cards in it and I would like to replace that power hungry computer with a lower power consumption device like a Mac Mini or similar and utilize an external FXO device to bring my phone lines into FreePBX/Asterisk.

While I utilize external SIP providers I do need at least one FXO for my Xfinity voice line.

I don’t know that macOS can be used for the PBX but that’s not a big deal, I can just use the standard distro instead but the big thing is wanting to add an external FXO adapter since the mini doesn’t have PCI slots.

I read the writeup on the Grandstream 410x devices and that looks to be a cheap way to do it but hate losing call waiting as a result, but if this is the only way to go without spending a fortune then maybe that is what I need to consider.

Any advice on what I might use for FXO that doesn’t require an internal card is appreciated.

Thank you!

You have FXO gateways from Grandstream, Sangoma, obi, yeastar, audiocodes and probably a couple more.

Are you looking for just one fxo port or do you need more than one?

Just one is all I really need.

I’ve been reading about the Raspberry Pi version of FreePBX but I don’t know if that is a viable replacement or not, do you lose a lot of features when using Pi over a regular computer?

Commercial Module Support, so it depends on your use case.

Only commercial modules. But if you are not planning on using any of them, then no, you don’t lose much.

Thanks for those replies, they are very helpful! I may seriously consider the Pi instead of a computer for my home PBX (my work PBX is also FreePBX and that’s the one that needs the horsepower and commercial modules).

Would the external FX0 still be the Grandstream? Is there an alternative to the Grandstream that doesn’t sacrifice call waiting?

What do you mean by sacrificing call waiting? You will hear the call waiting signal if a second call comes in.

According to the wiki at https://wiki.freepbx.org/display/FOP/Configuring+a+Grandstream+GXW-410X+Device+to+act+as+an+FXO+Gateway:

Each line can support one telephone call. You will not be able to use call waiting or three way calling from the phone company to have more than one call on a single phone line. However, you can use FreePBX/Asterisk to conference separate lines together to make a conference calls. The phone company can set-up multiple phone lines in a rotation, so that if one is busy, the call will ring in on the next available line.

Have Rasppbx at home with one telephone extension and a Grandstream 702HT adapter and load is VERY low. Just keep RPi updated as no automatic notification (without ‘admin’ commercial module) to let you know. Every Monday, manual check for updates, upgrade if needed. Running fine with no failure, so far. (Over a year now.)

Even better than call waiting is forward on busy. See if the provider has that feature, and if so, forward to a VoIP DID on busy.

More great info, thank you! @bob_dt, which rPi do you use? I’m thinking the 4B with a 32GB flash, but I know the flash has a limited read/write cycle and will eventually fail, do you use an external USB SSD or the flash?

@lgaetz I hadn’t considered that but it’s a great point. Xfinity does offer that.

That would be the challenge on talking to the provider. On the one hand, Xfinity is just another SIP provider (as is Comcast, their parent company) so connecting Asterisk straight to it is going to be up to them. On the other hand, we know that they are selling a service that competes pretty directly with Asterisk-based systems, so I could see them getting in the way.

I couldn’t find anything on the Xfinity website that could help the discussion without being a Comcast customer. Perhaps it’s time to trawl around their website looking for Asterisk support options. You never know - they may think we’re awesome.

In which regards? Do you mean as far as not needing an external FXO and talking directly to the Comcast/Xfinity phone line? I am 99% certain that’s not possible, from their standpoint they are just giving you an RJ11 for your phone line just like other providers, leaving it up to you to figure out what to do from there.

The FXS port that Comcast is providing is already a SIP account. The CPE that Comcast gave you has a built in SIP ATA. This isn’t traditional, copper based POTS.

So you can get an ATA or FXS gateway but just keep in mind that it will be SIP -> Analog (Comast device) then Analog --> Analog --> SIP to hit Asterisk and the reverse of that. It starts to become pretty convoluted which can make troubleshoot issues rather hard.

Edit: If this is Xfinity home service then I wouldn’t expect help from Comcast. PBX systems do not fall under residential/home service devices in most provider/carrier cases.

It is a RPi 3B with the usual 32Gb microcard for OS. (Sorry, there at home so I can’t tell you which Samsung microcard it was but, one of the better ones. I do remember that it had green accent color. Maybe that will help.)

When I made a call and ran htop on terminal on my desk top, used 30% of cpu average across the cores. So, plenty of power available.

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