Sky Networks "Skyphone" app leverages the the latest technology to offer, SIP based voice, video and text messaging services on iOS (iphone, ipad). Based on 3GPP IMS (IP Multimedia Subsystem standards , SkyPhone is designed as an OEM product that can be customized to fit service providers exact needs. It is perfect for service providers that offer wholesale, international and prepaid VoIP services to enterprise and retail customers. The incorporated SIP stack follows RFC 3261 and 3GPP TS 24.229 Rel-9 specifications, this will allow you to connect to any compliant SIP registrar. It also partially implements GSMA Rich Communication Suite release 3 and The One Voice profile V1.0.0 (LTE/4G, also known as GSMA VoLTE) specifications. The phone is setup to be centrally provisioned using encrypted https and our standard installation includes the provisioning server. It also features a visual voicemail with preintegrated implementations for Freeswitch based voicemail systems. The phone includes support for the STUN (RFC 3489/RFC 5389), ICE (RFC 5245) and TURN (RFC 5766) specifications allowing it to be used with the Sky Dance STUN/ICE/TURN Media server independently of a session border controller for far end NAT traversal or in conjunction with a SBC depending on scale and needs.