UPnP Architecture?

Universal Plug and Play

The UPnP architecture offers pervasive peer-to-peer network connectivity of PC’s of all form factors, intelligent appliances, and wireless devices. The UPnP architecture is a distributed, open networking architecture that leverages TCP/IP and the web to enable seamless proximity networking in addition to control and data transfer among networked devices in the home, office, and everywhere in between. Universal Plug and Play is a set of networking protocol that permits networked devices, such as personal computers, printers, internet gateways, Wi-Fi access and mobile devices to seamlessly discover each other’s presence on the network and establish functional network services for data sharing, communications, and entertainment.

What are the benefits of UPnP technology?

·         Media and device independence. UPnP technology can run on any network technology including Wi-Fi, coax, phone line, power line, Ethernet and 1394.

·         Platform independence. Vendors can use any operating system and any programming language to build UPnP products.

·         Internet-based technologies. UPnP technology is built upon IP, TCP, UDP, HTTP, and XML, among others.

·         UI Control. UPnP architecture enables vendor control over device user interface and interaction using the browser.

·         Programmatic control. UPnP architecture enables conventional application programmatic control.

·         Common base protocols. Vendors agree on base protocol sets on a per-device basis.

·         Extendable. Each UPnP product can have value-added services layered on top of the basic device architecture by the individual manufacturers.

What is Port Forwarding?

A router is like a post office. When you send a letter to someone, it first arrives at the post office and then it is sent to the recipient. Port forwarding means telling the post office (router) where the letter (data) should be sent. This way the router knows that it has to send the incoming Tunngle traffic right to your pc (and not to another one in the same network).PCs within a LAN are each assigned a LAN IP address by the router and can exchange data with each other. However, PCs within a LAN do not have direct access outside the network. Likewise, PCs outside the LAN cannot access them either. In other words, computers that are set up as web or FTP servers in a LAN cannot fulfill outside requests via the router directly.Tunngle works without the need of a port forward on most systems. As long as you can connect to a reasonable amount of players in a network you shouldn't worry. If, on the contrary, you see all other players in the network nick list marked with a red X, you might have to do this.

Advantages

Even if Tunngle is working fine without a port forward there are some advantages in setting up a port forward. If you forward the port you max out the possibility to establish connections with others. This means that you will be able to connect to peers that cannot receive inbound connections. If your friend hasn't access to his router, setting a forward on your side can help him connect to you.

Supported Methods

There are several alternative ways to forward incoming traffic to your PC:

Manual Port Forward: This involves accessing your router web configuration panel and setting a port forward rule for your PC IP address.

Automatic UPnP Port Forward: If your router supports UPnP, this allows Tunngle to automatically setup the rule without the need for you to access your router web configuration panel.

Port Trigger: If your router supports it, this involves accessing your router web configuration panel and setting a Port Trigger rule for Tunngle. This method doesn't require the knowledge of your PC IP address.

Automatic UPnP Port Forward

Tunngle provides a simple way to configure your Port Forward automatically. If you are not familiar with how routers work or if you like it simple, your best option is to go to Tunngle->System->Options and check UPnP. Tunngle will then attempt to configure your port forward automatically on the next restart. If you get the UPnP error it means that your current system configuration does not support UPnP as a Port forwarding method. In this case go back to 

Tunngle->System->Options and unchecked UPnP.

In case you are not able to log in remember that you can start Tunngle in Off-line Mode.

Please note that Tunngle UPnP depends on the following Windows Services:

SSDP Discovery

UPnP Device Host

You can use the community trouble-shooter to fix this. Check that your Firewall allows svchost.exe to make outbound connections. Also if you use UPnP on a certain port please verify that there is not already a port forward rule for the same port in your router.

Manual Port Forward

Required data

Configuring the Port Forward means telling to your router that the UDP data (the letter in our example) that arrives on the External Port 11155 should be forwarded to your PC on the same Internal Port. 
Imagine that you have more than one mailbox each painted in a different color. In our post office analogy:

Protocol: You can figure the protocol as the letter type

Destination IP: You can figure the Destination IP as your street address

External Port: You can figure the external port as the letter envelope color

Internal Port: You can figure the internal port as the color of the mailbox you want the letter to be delivered to you could set a rule that a green business letter would go straight into your green mailbox, while a red business letter could go into your red mailbox.