ZyXEL Communications PMG5318-B20A, User Manual

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Chapter 12 Remote Management
PMG5318-B20A User’s Guide
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12.7 UPnP
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.
12.7.1 What You Need to Know About UPnP
Identifying UPnP Devices
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.
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.
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 GPON Device allows multicast messages on the LAN only.
All UPnP-enabled devices may communicate freely with each other without additional configuration.
Disable UPnP if this is not your intention.