[Serusers] Help needed with SER imprementations

Hello, I´m new to SER Express and I needed to use SER, on the following imprementations, but do not know which to use. I want to use this imprementations for free in network internet calling, calling card via asterisk (a2billing), and PSTN calls for all the network users. 1. I need to setup SER, to routes all my incoming and outgoing sip calls, (in network users to users) free sip calls 2. Routes all PSTN calls to Asterisk for billing via a2billing and then Asterisk will do the PSTN call terminations of the calls. 3. All the sip user to be authenticated by Asterisk / a2billing for the billing via their user name and password. 4. SER to use asterisk for the users voicemail and other pbx features. Can anyone please help me out? Looking to hearing from you. Regards, Henry -- ================================ "Never Let Go Of A Dream Untill You Can Wakeup And Make It Happens" ================================