[Serusers] DNS SRV Record and VRRP/Keepalived

Hi all, I've a very difficult problem to solve...I have 2 SER process running over 2 separate machine...one is the primary and the other is the secondary Sip Proxy Server....my PSTN gateway support RFC 2782 (RFC 3263) very well and I like this approach to locate the SIP Proxy Servers, but my SIP terminal adapter doesn't support this protocol neither have the chance to set up the secondary (backup) proxy server...my workaround is to resolve the FQDN of the 2 SPSs in the DNS A Record with the virtual IP and to populate the DNS SRV records with the real ip (for the pstn gws) ....and here start the problem....in the ser.cfg I've set this: listen=Virtual_IP listen=Real_IP_NIC (listen=0.0.0.0 seems to not work) advertised_address=??? (which, the Virtual_IP from the inbound to outbound or the real ip address for calls outbound to inbound??) ...and there is many side effect...request proxied from my Sip Proxy server with Via Header Field Virtual_ip and Record_route with real_ip.....request coming from real-ip Proxy blocked from some firewall cause the pinhole is open but from request coming from virtual-ip and not from real_ip and so on..... Is there a way to handle this scenario?? Thanx to all, Verbal