cowlibob
14 Sep 2005, 07:55
Here follows an excerpt from an explanation of UPnP and worms 4: Mayhem. Enjoy.
Introduction
Universal Plug ’n’ Play (Henceforth UPnP) is a networking technology / protocol championed by Microsoft.
It consists of two elements – devices to be controlled (Device Host API) and devices seeking to control others (Control Point API).
Support for Device Host API was introduced in Windows XP (WinXP) and numerous hardware routers / access points.
Support for Control Point API was introduced in Windows Millennium Edition (WinME), WinXP, WinXP Pro.
Its aim is to allow devices to be found and controlled across a network.
Our aim is to ease configuration woes for end users.
The Worms 4 Mayhem / NAT Problem
Unlike many other popular network games (e.g. Battlefield 2), Worms 4 Mayhem requires end users to act as game servers.
This means that any pair of players wanting to play need to communicate with each other. Battlefield servers are often dedicated and run by people with networking knowledge. This means that Battlefield clients need not usually worry about networking issues.
Worms’s peer-to-peer topology means the problems are shifted to regular players.
Firewalls and Routers both impede connections, but in different ways.
• Firewalls may block incoming / outgoing network traffic.
• Routers / Bridges / NATs need to redirect traffic.
Our experience with Worms 3D and early Worms 4 Mayhem trials has shown that users can generally configure firewalls to allow game traffic.
However, where a hardware router, wireless access point, or Windows Internet Connection Sharing is used; configuration becomes an issue.
The Solution
Part of the UPnP framework allows a remote router to be configured to forward ports.
Worms 4 Mayhem will contact any relevant device and configure it to pass any incoming TCP traffic received on port 5911 to the local machine.
This allows remote worms clients to connect to the local Worms client, assuming no firewalls block said traffic.
Limitations
Firewalls and NATs present two different problems. This UPnP work addresses NAT port forwarding only.
A device (Router, Access Point, or Windows XP Internet Connection Sharing) must support UPnP and have it enabled.
Windows 98 does not support UPnP.
Port forwarding can only direct traffic to one computer for each port. Hence, as we are using only 5911, port forwarding can be configured for only one machine behind any given NAT device.
Testing has shown that at least once particular device purports to be UPnP compatible and enabled does not respond to the port forwarding commands; A Thompson SpeedTouch 510 v4 ADSL modem / router.
Introduction
Universal Plug ’n’ Play (Henceforth UPnP) is a networking technology / protocol championed by Microsoft.
It consists of two elements – devices to be controlled (Device Host API) and devices seeking to control others (Control Point API).
Support for Device Host API was introduced in Windows XP (WinXP) and numerous hardware routers / access points.
Support for Control Point API was introduced in Windows Millennium Edition (WinME), WinXP, WinXP Pro.
Its aim is to allow devices to be found and controlled across a network.
Our aim is to ease configuration woes for end users.
The Worms 4 Mayhem / NAT Problem
Unlike many other popular network games (e.g. Battlefield 2), Worms 4 Mayhem requires end users to act as game servers.
This means that any pair of players wanting to play need to communicate with each other. Battlefield servers are often dedicated and run by people with networking knowledge. This means that Battlefield clients need not usually worry about networking issues.
Worms’s peer-to-peer topology means the problems are shifted to regular players.
Firewalls and Routers both impede connections, but in different ways.
• Firewalls may block incoming / outgoing network traffic.
• Routers / Bridges / NATs need to redirect traffic.
Our experience with Worms 3D and early Worms 4 Mayhem trials has shown that users can generally configure firewalls to allow game traffic.
However, where a hardware router, wireless access point, or Windows Internet Connection Sharing is used; configuration becomes an issue.
The Solution
Part of the UPnP framework allows a remote router to be configured to forward ports.
Worms 4 Mayhem will contact any relevant device and configure it to pass any incoming TCP traffic received on port 5911 to the local machine.
This allows remote worms clients to connect to the local Worms client, assuming no firewalls block said traffic.
Limitations
Firewalls and NATs present two different problems. This UPnP work addresses NAT port forwarding only.
A device (Router, Access Point, or Windows XP Internet Connection Sharing) must support UPnP and have it enabled.
Windows 98 does not support UPnP.
Port forwarding can only direct traffic to one computer for each port. Hence, as we are using only 5911, port forwarding can be configured for only one machine behind any given NAT device.
Testing has shown that at least once particular device purports to be UPnP compatible and enabled does not respond to the port forwarding commands; A Thompson SpeedTouch 510 v4 ADSL modem / router.