According to our in-house AD guru:
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The recordedname will end up being the size of the wave file x 1.3.
All other Unity attributes for the user object are roughly 500-600 bytes. This means, if the average recorded name length is 2 seconds and G.711 is used, the Unity subscriber attributes including recorded name will be about +/- 21 KB. For G.729a, it will be about +/- 2.9 KB or little larger. To get the total size of a given user object in AD, it is necessary for the customer to know what the average size of their user is now, and then they can reasonably add the formula above to determine the added increase for each Unity subscriber.
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Jeff Lindborg
Unity Technical Lead/Answer Monkey
Cisco Systems
lindborg@cisco.com
http://www.AnswerMonkey.net (new page for Unity support tools and scripts)