The timer on recording your greeting for your ext mailbox is set to 30 sec. I see that you can SSH into and do some programming to extend the greeting length. Needing to be able to set the timer in the Ext programming by just entering how long you want the Ext user to be able to record there greeting. This is a common request from users on just about every install. To me this is a very easy fix just put a timer field in the ext box under Voicemail. not wanting to SSH just to extend greeting length.
Voice Mail greeting timer