Getting started with UPNP
UPNP is a standard,as specified in UPnP Device Architecture 1.0, version 1.0.1, that facilitates pervasive peer-to-peer network connectivity intelligent appliances,wireless devices and PCs of all form factors.It brings easy-to-use,flexible, standards-based connectivity to ad-hoc or unmanaged networks whether in the home,in a small busines,public spaces, or attached to the internet. UPnP technology provides a distributed,open networking architecture that leverages TCP/IP and the Web technologies to enable seamless proximity networking in addition to control and data transfer among networked devices.
Advertisement Expiry Time is the duration of the Advertisement.The default is 1800 secs and is configurable.Generally,device vendors should choose a value that corresponds to expected device usage, short durations for devices that are expected to be a part of the network for short periods of time, and significantly longer durations for devices that are expected to be long-term members of the network.
TTL To limit network congestionm the time-to-live (TTL) of each IP packet for each multicast message should default to 4 and should be configurable.When the TTL is greater than 1, it is possible for multicast messages to traverse multiple routers.
SSDP Packet Repeat Count The number of times an SSDP packets needs to be sent.If a root device has d embedded devices and s embedded services but only k distinct service types,this works out to 3+2d +k requests.In effect, (SSDP Packet Repeat Count)*( 3+2d +k) packets would be sent.