This article explains how to use the Protel LTS administration web interface (or extension user web interface) to program forwarding behavior for an extension user.  Users can set forwarding behavior themselves, by using feature codes that they dial right from their phone.  See HERE for a printable guide to using feature codes. Feature code forwarding, however, does not return a forwarded call that goes unanswered to the PBX voicemail.  You would use the PBX extension forwarding options described below if you want to create a forwarding behavior that returns an unanswered call to the extension user's PBX voicemail, or if you need to create a permanently forwarded extension on the PBX that does not have an IP phone registered to it and always forwards out to a particular external phone number - an answering service, another branch office, or a support number, for example.

Listed below are instructions for setting PBX-based forwarding behavior for an extension using the Modify Existing Extension/Forwarding interface:

The default setting for all extensions is "No Forwarding"

To set a Forward on No Answer (delayed forward), check the Forward box to reveal the additional data fields

The "Times to Ring" field is referring to the phone that the call is being forwarded to - not the desk phone of the extension. If the forwarded call is not answered in the defined number of rings, the call returns to the user's PBX voicemail.  The number of times that the desk phone will ring before the forward kicks in is not set on this page.  This is set on the SIP & Dialing tab:

The "Forward to" field should be a 10-digit telephone number. Check the "Announce Caller Name" option if you want the system to have the caller record their name.  The system will then announce the caller name when the forwarded call is answered, and give the option of accepting or rejecting the call.

To set a Follow-Me Forward, check the "Follow" box to reveal the additional data fields.  

This works just like the "Forward" option described above, except that you can chain up to 3 successive external numbers for the PBX to attempt.  If there is no answer after the 3rd number, the call returns to the user's PBX voicemail.