Not sure what is happening on this one. UC520 latest sw pack has decided that the onboard FXS ports will no longer dial out. Dialing inturnal extensions is fine both ways. DID's incoming to those FXS ports also work. Dialing access code 9 for the PRI simply no go. I have rebooted the UC520 I have even changed the FXS seetings from Fax to Common area and back again seeing if that would clear up any bugs in the config, but still no luck.
So simply put FXS ports on UC520 will no longer allow outbound calls.