Investigating uPNP with python for fun and profit.
SSDP is an interesting uPNP protocol – devices advertise their capabilities on the network and leak valuable information. SSDP is very similar to http, except its run over UDP.
https://tools.ietf.org/html/draft-cai-ssdp-v1-03
SSDP clients discover SSDP services using the reserved local administrative scope multicast address 239.255.255.250 over the SSDP port.