What is Teredo Service

Can anyone please explain me about the teredo service in networking world. i want to know what is the teredo service all about ? Is it a useful service ? Please provide all the necessary information about the same...thank you.

Teredo is an IPv6 transition technology that provides address assignment and host-to-host automatic tunneling for unicast IPv6 traffic when IPv6/IPv4 hosts are located behind one or multiple IPv4 network address translators (NATs). To traverse IPv4 NATs, IPv6 packets are sent as IPv4-based User Datagram Protocol (UDP) messages.

For more information on Teredo including Teredo addresses and packet structures—and detailed explanations of how communication is initiated between Teredo clients, Teredo host-specific relays, and IPv6-only hosts using the IPv4 Internet, the IPv6 Internet, Teredo servers, and Teredo relays - click here

Teredo is a tunneling protocol which is designed to grant IPv6 connectivity to nodes that are located behind IPv6-unaware NAT devices. It serves a way of encapsulating IPv6 packets within IPv4 UDP datagrams that can be routed through NAT devices and on the IPv4 internet.

Functions -

• diagnoses UDP over IPv4 (UDPv4) connectivity and discovers the kind of NAT present (using a simplified replacement to the STUN protocol);
• assigns a globally-routable unique IPv6 address to each host using it;
• encapsulates IPv6 packets inside UDPv4 datagrams for transmission over an IPv4 network (this includes NAT traversal);
• routes traffic between Teredo hosts and native (or otherwise non-Teredo) IPv6 hosts.

I have a home router with the wireless option turned off, Netgear box. I use it strictly for two reasons. one is to hide behind something so I am not so vulnerable to everyone and to have a plug in place for my laptop directly into the Internet and hid that too. I am running XP Prof on the desktop and Win 7 on the laptop. I have tcp/ip and Microsoft ip6 running on both mostly just having the desktop plugged in. Why did Teredo show up? It says that the connection is Internet. the other connection is the network card. so I see two little double commuters flashing away in the system tray. Please explain what the tunneling is. Is that some secret, don't see, way of communicating with my computer? Why do I need all this stuff? I do not like ip6 because I can not read the addresses. Where can I get the nonMicrosoft ip4 and ip6 protocols to run on my XP to be more up to date?