Shot in the dark: Can't dial DP715 extension, but can dial out?




We have an Ipitomy PBX and we mostly use Ipitomy phones. For one extension we had an AASTRA handset but it broke so we replaced it with a Grandstream DP715. It can dial out just fine, but nobody , locally or externally, can call its extension. It goes straight to voice mail.

Is this model not compatible with Ipitomy?

Has anybody ever encountered this issue?

Any feedback would be appreciated.

Thank you and have a pleasant day.