These settings are pretty much standard on all systems and seldom need to be changed. If they do need changing, it should be done in a reverse order, ie: first the adjunct, then the PBX, then the Central Office then the Toll Office. To further clarity, if you are hooking up a non-Avaya Auto-Attendant to a Merlin, it is the responsibility of the Auto-Attendant manufacturer to ensure compliance with the Merlin. If you are connecting a non-standard PBX to the Central Office, it is the PBX manufacturers resposibility to ensure compatability with the CO, etc.
Therefore, you should contact your equipment manufacturer, advise them you are connecting to a Avaya Merlin PBX and ask them how to adjust their settings in order to conform.
franke