Biggest caveat that I see with customer as user functionlity pertains, is the ability to get the voicemail in your inbox on mobile phone users with Unity. Unfortunatley Connection requires IMAP connection, which is explained above in the other respo...
Another good Q and A on Mobility Manager and Mobile Connect for SNR: http://www.cisco.com/en/US/prod/collateral/voicesw/ps6788/vcallcon/ps6567/prod_qas0900aecd8055d50d.html
For Microsoft OCS (Enterprise Voice) there is no additional licensing to be purchased. Enterprise voice is the most common method of integration into the OCS enviroment. With that verison it also supports direct SIP trunking without a gateway (ex.Dia...
I have a customer (university) using IPcelerate to ring into the on campus operator. However this doesnt elude from the fact that it will still cost $$. I know they have changed licensing structure's to "package" up all the features, so it isnt as a...