The next step in UPnP networking is event notification, or "eventing". The effects of the action, if any, are modeled by changes in the variables that describe the run-time state of the service. Like function calls, in response to the control message, the service returns any action-specific values. Control messages are also expressed in XML using the SOAP|Simple Object Access Protocol (SOAP). To do this, a control point sends a suitable control message to the control URL for the service (provided in the device description). After a control point has retrieved a description of the device, the control point can send actions to a device's service. The next step in UPnP networking is control. For each service, the description includes a list of the commands, or actions, to which the service responds, and parameters, or arguments, for each action the description for a service also includes a list of variables these variables model the state of the service at run time, and are described in terms of their data type, range, and event characteristics. The description also includes a list of any embedded devices or services, as well as URLs for control, eventing, and presentation.
#WHAT IS UPNP SERIAL#
The UPnP description for a device is expressed in XML and includes vendor-specific, manufacturer information like the model name and number, serial number, manufacturer name, URLs to vendor-specific web sites, etc. For the control point to learn more about the device and its capabilities, or to interact with the device, the control point must retrieve the device's description from the URL provided by the device in the discovery message. After a control point has discovered a device, the control point still knows very little about the device. The next step in UPnP networking is description. The UPnP discovery protocol is based on the Simple Service Discovery Protocol (SSDP). The fundamental exchange in both cases is a discovery message containing a few, essential specifics about the device or one of its services, for example, its type, identifier, and a pointer to more detailed information. Similarly, when a control point is added to the network, the UPnP discovery protocol allows that control point to search for devices of interest on the network. When a device is added to the network, the UPnP discovery protocol allows that device to advertise its services to control points on the network. Given an IP address, the step 1 in UPnP networking is Discovery. If during the DHCP transaction, the device obtains a domain name, for example, through a DNS server or via DNS forwarding, the device should use that name in subsequent network operations otherwise, the device should use its IP address. If no DHCP server is available, that is, the network is unmanaged, the device must assign itself an address. Each device must have a Dynamic Host Configuration Protocol (DHCP) client and search for a DHCP server when the device is first connected to the network. The foundation for UPnP networking is IP addressing. Extensibility Each UPnP product can have device-specific services layered on top of the basic architecture. Programmatic control UPnP architecture also enables conventional application programmatic control. UPnP enables vendor control over device UI and interaction using the browser as well as conventional application programmatic control. UPnP does not specify or constrain the design of an API for applications running on control points OS vendors may create APIs that suit their customer's needs. Operating system and programming language independence Any operating system and any programming language can be used to build UPnP products. User interface (UI) Control UPnP architecture enables vendor control over device user interface and interaction using the web browser.
#WHAT IS UPNP DRIVER#
No special device driver support is necessary common protocols are used instead. Media and device independence UPnP technology can run on many media that support IP including Ethernet, FireWire, IR (IrDA), power lines (Power line communication|PLC) and RF (Bluetooth, Wi-Fi). Devices can leave the network automatically without leaving any unwanted state (computer science)|state information behind. Dynamic Host Configuration Protocol|DHCP and Domain Name System|DNS servers are optional and are only used if they are available on the network. A UPnP compatible device from any vendor can dynamically join a network, obtain an IP address, announce its name, convey its capabilities upon request, and learn about the presence and capabilities of other devices. The UPnP architecture supports zero-configuration Computer network|networking. It is a distributed, open architecture based on established standards such as internet protocol suite|TCP/IP, User Datagram Protocol|UDP, HTTP and XML. The UPnP architecture allows peer-to-peer networking of Personal Computer|PCs, networked appliances, and wireless devices.
0 kommentar(er)
