Before making changes, print out what you have in case you make a mistake
Required values on the TN
CLS: CFXA - To allow calls to be forwarded externally:
Digital sets need KEY CFW. Analog sets need FTR CFW. The user activates CFW from their phone.
NCOS/TGAR: User must be capable of placing the call to where they wish to be Call Forwarded.
Customer Data Block RDR_DATA OPT: Should include CFF (not CFO)
If you do not know what trunks or route your call is going over, you're in over your head already. Seek assistance from of a qualified technician (read as "someone else you can blame") before you attempt any changes. You may wish to use some of these terms and phrases.
Link to this page: http://www.ghtrout.net/rdr/cfxa.html