Aastra 57i cannot make outbound calls through localTrixbox server

Could be line trouble. Have your carrier check.

probably means that you either have a missed call or message on your machine try deleting the call history and deleting all old messages. that might turn it off

set it to the value of the open SIP port of your phone system (5060?).

All incoming calls get a busy signal

This Depends on your providers system . If yo go and retrieve your messages and hit 4 3 2 2 this will get you to nowhere you can record a message for incoming calls. If you want to change you message for when some calls you and you are on the phone you would do the same as above but hit 4 3 2 1. That is where you change your "on the phone message" never put a date in that one. Just record " hi I am on the phone at the moment please lease a message at the tone" Hope this helps

try out hitting * and # when restart phone for hard reset, or 4 and 6 for factory reset.

Try 22222

Forwarding is through the plan provider and part of the voice mail system.

Telephony configuration might necessary...

go HERE1 & HERE2