It’s very difficult to said what exactly causes and how to solve on.
But regarding to SIP message “484 “Address Incomplete” it could understand as; provider is expecting call with a prefix, therefore should check with provider dial pattern rules to carry out calls and set provider dial patterns on outbound routes.
Otherwise should collect call and event log information.
which shows complete settings (for another device) and a working solution. Do the analogous codec settings: disallow=all allow=alaw
and test. If no luck, perhaps your number format is incorrect. If incoming is working, it’s a good bet that if you send a call in the same format as incoming caller ID, it will work.
If you still have trouble, at the Asterisk command prompt type sip set debug on
make a test call, paste the Asterisk log for the call at pastebin.freepbx.org and post the link here.