Nat Traversal; Cautions With Upnp; Upnp And Zyxel - ZyXEL Communications P-320W v3 User Manual

Chapter 16 Universal Plug-and-Play (UPnP)

16.3.2 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.

16.3.3 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 P-320W v3 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.

16.3.4 UPnP and ZyXEL

ZyXEL has achieved UPnP certification from the Universal Plug and Play Forum
UPnP™ Implementers Corp. (UIC). ZyXEL's UPnP implementation supports
Internet Gateway Device (IGD) 1.0.
See the following sections for examples of installing and using UPnP.
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