Hi,
I have been working with Cisco VoIP since 2001 and Asterisk and freepbx ,trixbox, elastix since 2007.
I have been developing software using VB since 1996 ( VB3 ) and on linux platform using PHP since 2007,
I have not developed for Oracle Siebel 8.1 before , but have a very good experience on developing software on both windows and Linux platforms,
I have developed applications for Cisco Callmanager to interact with windows and believe this will be quite similar ,
I have read a little about Siebel Communications Server and I believe I can complete the project in time.
I'm not bidding on the project just because of price , but because I'm having knowledge of both worlds (i.e. Windows development and Asterisk).
That being said I would like to have a little chat about your project to better understand the needs of the project
regards,