If your desk Avaya phone can make outgoing calls just fine, but all incoming calls go directly to your voicemail, try this:

Press the Phone button located to the right of the OK button on your desk Avaya phone.  Locate the Send All Calls key (usually bottom left) and see if it is pressed or activated.  If so, press the button once to remove.

Your calls should come to your phone now.

If this did not resolve the issue, click the Submit New Ticket link above to have a Technician assist.