April 23, 2008 9:59 PM BST
In my opinion, defining VAS depends on 2 different angles; telecom angle or IT & Telecom angle.
In reality, and thinking on the business customer, IT&Telecom will define together VAS. Let me give you an example: imagine a mid-size business, that decides to take all the Computer Servers to a Hosting ISP, install a terminal server and migrate all PC's to thin-clients. At the same time, decides to get rid of the PBX and install (in hosting schema) an IP-PBX with a hosted mediagateway for PSTN. Then decide to purchase IP Phones. At the same time, they mobilize the employees email accounts with a hosted Blackberry Enterprise Server.
The company decides now that just one DSL access is too risky, and hire an aditional DSL access, or fiber access if available.