why the multicast port number is not 1900?

"Charles Tu" <[email protected]> Thu, 15 Jan 2004 16:22:56 +0800

Newsgroups	gmane.linux.upnp-sdk.general
Message-ID	<03df01c3db40$cac69e30$e201a8c0@charlespc>

Dear all,
I got the UPNP SDK installed fine, and got the IGD - Linux Internet Gateway Device running fine.
My XP boxes see the device and specify that it is a IGD - Linux Internet Gateway Device.
But after installed XP Service Pack 1a, the icon of IGD - Linux Internet Gateway Device in My Network Places disappeared.

Then I use Sniffer to check the packets, I discovered the packet of multicast did not use port 1900.
Anyone can tell me how to correct it?

Give me a hand please, and sorry for my poor English.
 
best regards,
Charles