My configuration:
WinXP Pro
Linksys WRT54G with UPnp enable
MSN Messenger 6.2
Messenger detect the router is UPnP : Tools/Options/Connection Tab/Advanced
connection information message is "You are connected to the internet through
a UPnP port restricted NAT"
...But no sound!!!
Try this (it worked for me)
1) Verify SSDP Discovery Service is Running
2) Verify Universal Plug and Play Service is Running
3) Internet Gateway Device and Control Client is enabled.
How to install it :
Go to ADD/REMOVE PROGRAMS in Control Panel
Choose ADD/REMOVE WINDOWS COMPONENTS
Click on NETWORKING SERVICES and then choose DETAILS
Make sure 'Internet Gateway Device Discovery and Control Client' is
checked
Make sure 'Universal Plug and Play' is also checked.
Hit OK/APPLY to make sure everything is enabled. Reboot.
4) In CONTROL PANEL/NETWORK CONNECTIONS, right click on "Internet
Connection" and select the Properties command. In the General Tab, click on
Settings to view current UPnp opened ports. Add the following ports :
Voice In, your computer IP (192.168.x.x), port 6901, UDP
Voice Out, your computer IP (192.168.x.x), port 6901, TCP