[Serusers] Asterisk and SER Together - Cenario and Doubt

Hi Everyone, I want to configure the following cenario: SIP Server (SER): as a proxy server and Registrar Asterisk : for the PSTN Gateway/Vocemail/Forward/Conference Server. I've already configured SER to auth my internal users via mysql which is installed at SER server machine, the database is working fine so as users authentication. I've managed to make 2 sip cpe (SIP UACs) authenticate at my Ser server and talk to each other locally with no delay or noise. My goal is to auth an user at SER, making logic route that sees if this certain user is dialing an international call to a certain number, if that is true, forward the request to Asterisk and Asterisk does the auth using username and password of an account registered at another VoIP server (Go2Call) outside my network (this account is another one from the go2call and not one of my Ser Server). I already know that ser don't act like an UAC in this case, but I know asterisk does forwarding the request with username and password. For a more detailed view see the graph below. ---------- | Go2Call | > Outside VoIP for International Calls ---------- | | | ------------ ----- = Asterisk = > UAC (too)/Forward /PSTN/Voicemail ------------ | | ------- = SER = > Sip Proxy / Registrar / Mysql DB ------- | | ---------------- = VoIP Clients = ==> My VoIP Clients / Sip Phones ---------------- First I would like to know if it is possible, 'cause it is my first time with VoIP Technology and Software, and Second I would like to know if is there somebody that have already configured this cenario to change some ideas. I would also like to know if it's possible to do billing of my clients using cdr module from Asterisk, once my sql is working with SER to authenticate them. Linux is no problem. What i'm asking is for help and a change of ideas and confs, not for paid solutions. If someone can help me it would be really realy aprecciated. Sorry for my terrible Brazilian English. Best Regards. Felipe Martins -- Felipe Martins Linux System Administrator Tep Solution Provider Mundivox Communications Rua Lauro Muller, 116/Sala 505 RJ - Brasil - 22290-906 Tel.: 55 21 3820-8839 Fax.: 55 21 3820-8844