Android voip dialer with build in encryption/tunnel

Required to make a android sip dialer with build in tunneling and encryption on a Linux based platform. the platform must be able to handle 1000 concurrent calls 2 way calling out going and incomming the dialer must be integrated to wok with asterisk and a2billing system option for new account registration save userid and password option to reset forgotten password refill credit via paypal should be custom built and able to add additional features later. should show customers current balance, call history etc... highly secured against bruit force and other attacks highly stable and reliable below specs: # VoIP calls with auto QoS using the SIP protocol standards (both incoming and outgoing calls) # Android OS: [login to view URL] - and above # Connection: GPRS, EDGE, WiFi, 3G, 4G (all above 15 kbits) # Built-in tunneling and encryption (for both the signaling and the media) # Codec: G.711 (PCMU and PCMA), GSM, Speex, iLBC, G.729 G.723 # Automatic fine-tuning (including codec selection) depending on your peer capabilities, network speed and CPU power # AEC (acoustic echo canceller), Denoise filter, AGC (automatic gain control), PLC (packet loss concealment), Silence suppression # System phone-book # Call history # Balance and rating display, call timer, status logs, detailed logs # Multi-tasking support -listening for incoming calls in the background # Speakerphone, Mute and Hold # DTMF (RFC2833 or INFO method) # NAT/Firewall support, stable SIP and RTP ports, auto QoS, light STUN protocol and auto configuration # DNS SRV record lookups # Logging support for trouble shooting