An ISUP/SIP gateway is implemented to encapsulate SS7 location requests from a switched telephone network into an Internet protocol SIP message including one or more location objects. The ISUP/SIP gateway is implemented between a mobile switching center (MSC) and a VoIP positioning center (VPC) to provide support of unlicensed mobile access (UMA) voice over Internet Protocol (VoIP) call routing, e.g., for E9-1-1, 4-1-1, 2-1-1, etc. The disclosed location objects that are encapsulated into a SIP message includes calling party number, called party number, CGI, International Mobile Subscriber Identity (IMSI), mobility indicator, and/or access point MAC address. At the SIP/ISUP gateway, SS7 integrated services user part (ISUP) location request messages are encapsulated within SIP. The SIP encapsulated location request message is then routed over the Internet to a destination VoIP positioning center (VPC).