Two major US-based airlines were in the process of combining their IT infrastructure following a well-publicized merger.  They called on PSS to help them migrate from four different legacy IVR platforms to a single IP-based next-generation VoiceXML platform that could be standardized across all their operations in multiple locations.  The customer selected a Holly IP-IVR, which natively supports a SIP-based VoIP telephony interface. They planned to use existing Cisco gateways and middle-tier routers to perform the necessary conversion from a Rockwell TDM-based telephony switch to VoIP/SIP for the Holly IP-IVR.