Hi Ravi -
Are these customers using voicemail system today, such as Octel or Nortel? If so, how many ports are in use for this system and what is the port utilization (meaning during peak usage how many ports are in use)? This number will give you a good feel for the number you should start with. The next question would be will these customers be using unified messaging and have the ability to play voice messages from Outlook to PC speakers. The reason behind this question is that, over time, users typically will switch from using the phone interface, where a port is required on the Unity system, to playing voicemail back to PC speakers, where it is streamed from the Exchange server, and does not require a Unity port. The minimum number of ports for a new Unity server license is 32 and in this configuration you can use MSDE 2000 as the database. 32 ports and above, or Unity with failover, uses SQL 2000 for the database. Here is a great resource that references the Unity supported hardware platforms and the number of ports for each - http://www.cisco.com/en/US/customer/products/sw/voicesw/ps2237/products_data_sheet0900aecd802132ef.html
Regards,
Ginger
