The Simple Service Discovery Protocol (SSDP) is at the heart of the Universal Portable Protocol Stack
(UPPS). The SSDP protocol is cross-language and cross-platform and is based on HTTP. With the Simple Service Discovery Protocol (SSDP), requests and messages are sent in the form of HTTP requests or HTTP responses via User Datagram Protocol (UDP). After logging into a network, the SSDP service checks the request and sends a replay message with the appropriate label.