Getting A PSTN Dialtone On An ATA [SOLVED]

I see this old thread with no answer:

How To Get A PSTN Dialtone

I have something similar, a couple of Grandstream ATAs. I previously had them misconfigured with extensions pointing at the trunks. Although this was wrong, it did allow me to get a dialtone on each of the FXO ports and then dial directly out.

Right now I just have the trunks and and an outbound route using both the trunks. This is working in the proper, approved “from the PBX” dialtone method. Calls are routed between the two trunks as per the outbound route rules.

But I can also directly dial the number of the first trunk and get a PSTN dial tone on that trunk. Yay! But I’d also like to dial the number of the second trunk and also get a dial tone there.

I see notes about setting up another outbound route using only the second trunk somehow but can’t quite figure it out. Perhaps using a virtual extension and caller id to connect them or something. I tried using a dial pattern but that wasn’t working either.

Any ideas how to get directly to that second trunk?


I created a new outbound route that has only the trunk I am trying to reach in the trunk sequence. I created a dial pattern that would uniquely select this route. In this case a prefix of 99 and a match pattern of “X.” I moved this route to the top of the route tree.

So if anyone prefixes their number with 99, it will be routed out this trunk and FXO port.

To get a dial tone, I’ve created a shortcut on my phones of 99 plus the number of the trunk. Viola! PSTN dial tone.