Hi CF,
Hope all is well :)
The Voicemail Pilot Number is the DID number that callers use to reach Unity and the Hunt Pilot Number (usually the same as Voicemail Pilot number) is where the association is done with all the voice mail ports that were added to the Line Group. This is how Cisco CallManager routes the call to the next available voice mail port.
The Voicemail Pilot really comes into play alot more when Callmanager is integrated with multiple Voicemail systems and you want calls to certain numbers to route specified systems. Also in this scenario the Voicemail Pilot in conjunction with the voicemail profile determine which system to route the user to when the Message button on the IP Phone is pushed.
A voice-messaging profile can represent either a specified voice-messaging profile or a default voice-messaging profile. (Choose default voice-messaging profiles by choosing None in the Voice Messaging Profile drop-down list box in the Directory Number Configuration window.)
A voice-messaging pilot in the voice-messaging profile identifies the voice-messaging system to which redirected calls go. The combination of a directory number and voice-messaging mask defines the voice-messaging mail box.
CallManager 4.0(x) Voice Mail Port Creation with Unity Voice Mail (NON-FAILOVER)
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a0080232450.shtml#wiz5
Hope this helps!
Rob
