VIVA offers IP based Converged Communications Solutions. You may contact VIVA for SIP Trunking, IP PBX & PSTN integration, MS OCS & IP PBX integration, Managed VoIP and ''''Secure'''' VoIP.
It is a method of communication based on text messaging between two fax machines, the first one calling to other one to send a fax, the recipient receives a text on A4 paper and after that communication process ends.