ZyXEL nbg-5715 Guia Do Utilizador

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NBG5715 User’s Guide
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Universal Plug-and-Play (UPnP)
21.1  Overview 
This chapter introduces the UPnP feature in the web configurator.
Universal Plug and Play (UPnP) is a distributed, open networking standard that uses TCP/IP for 
simple peer-to-peer network connectivity between devices. A UPnP device can dynamically join a 
network, obtain an IP address, convey its capabilities and learn about other devices on the network. 
In turn, a device can leave a network smoothly and automatically when it is no longer in use.
21.2  What You Need to Know
UPnP hardware is identified as an icon in the Network Connections folder (Windows XP). Each UPnP 
compatible device installed on your network will appear as a separate icon. Selecting the icon of a 
UPnP device will allow you to access the information and properties of that device. 
21.2.1  NAT Traversal
UPnP NAT traversal automates the process of allowing an application to operate through NAT. UPnP 
network devices can automatically configure network addressing, announce their presence in the 
network to other UPnP devices and enable exchange of simple product and service descriptions. 
NAT traversal allows the following:
• Dynamic port mapping
• Learning public IP addresses
• Assigning lease times to mappings
Windows Messenger is an example of an application that supports NAT traversal and UPnP. 
See the NAT chapter for more information on NAT.
21.2.2  Cautions with UPnP
The automated nature of NAT traversal applications in establishing their own services and opening 
firewall ports may present network security issues. Network information and configuration may also 
be obtained and modified by users in some network environments. 
When a UPnP device joins a network, it announces its presence with a multicast message. For 
security reasons, the NBG5715 allows multicast messages on the LAN only.