Calls between two Voxalot transactions

[MikeT]

I'm having problems making calls between two Voxalot accounts. Both ATAs are registered to Voxalot (checked on account details page), I have no problems making test calls to *600 and *500. However, when I'm trying to call one account from the other, either by dialing its 6-digit number or dialing *010 followed by 6-digit number, the call goes straight to VoiceMail (if enabled), or I get a message saying the call can't be connected (VM disabled).

I believe the problem is on Voxalot side, could you take a look?

Account numbers available upon request.

Sincerely,

Mike

Update: It might have something to do with the codecs. The ATA I'm trying to call is SPA3102 and it has preferred codec set to G.729a, Use only preferred -> Yes.