I have been using a SPA232d for POTS to freepbx with no problems. The spa unit is now very noisy and unreliable so I have purchased a Grandstream HT813 to use only the fxo connection. I have setup a chanpjsip trunk which is shown as registered by freepbx and available. Calls do not connect in or out.
I have changed the dial tones and other tones to what I found as UK values but I am stumped by current problem.
Does anyone have any experience of this device with freepbx especially if any UK user can assist.