I am having trouble routing inbound calls to a SIP ATA for a fax line. Running on Server Edition version 10.1 with 30 SIP trunks. The ATA is registered and I can make outbound calls and call it internally and it rings fine. When I assign an external number to it I get a busy signal. Monitor is showing
I have contacted the carrier and they have confirmed they are using G.711u for faxing and I have that setup on both the ATA and the extension. I have tried None. T.38 and T.38 fallback with the same results. If I point that DID to a physical phone it will ring in fine. Just when I have it pointed to the ATA. The ATA is an Audio Codes MP-112FXS. Any idea what could be going on?

I have contacted the carrier and they have confirmed they are using G.711u for faxing and I have that setup on both the ATA and the extension. I have tried None. T.38 and T.38 fallback with the same results. If I point that DID to a physical phone it will ring in fine. Just when I have it pointed to the ATA. The ATA is an Audio Codes MP-112FXS. Any idea what could be going on?