MSN Messenger does IM, file transfer and video but no audio over DSL

[luisr]

I recently got DSL at home and since then I have been unable to use the audio feature of MSN Messenger 6.0 in Windows XP Home. I can do video (at least I can see the other person - I don't have a camera), messaging, transfer files both ways, but audio doesn't work.

I know it is related to the DSL connection because if I connect right there via dial-up to the ISP then it is possible to use audio in MSN Messenger. Once the dial-up connection is closed and the DSL connection becomes the active connection again, I cannot connect for audio again.

Asking in a forum where locals who seem to know enough of the local DSL service hang out, told me to ask the ISP to open ports 1863 and 6981. My DSL modem (ZyXEL Prestige 623-41) includes a NAT router and fiirewall but the ISP does not provide us the password required to access the modem configuration. You call their help desk and they will connect to your modem and open the ports remotely. I called my ISP and they opened (or so told me the technician) these two ports. Later I tried again the audio thing and didn't work.

Before I get suggestions about universal plug-and-play, as far as I know this is not required with MSN Messenger version 6.0. I disabled UPnP some time ago (following suggestions found in www.grc.com) and even with that disabled, I am able to use audio via dial-up. It is just via DSL that I can't.

Any suggestions regarding other ports that might be needed? How can I tell if ports 1863 and 6981 are open or at least not blocked by the router?

The Windows XP firewall is enabled in its default configuration. Again, this does not seem to be the problem since I can do audio via dial-up and the firewall is enabled in both the dial-up and the LAN connection I use for DSL.

Help!!

[glc]

Can you exchange the Zyxel for a standard bridge modem and use the WinXP built-in PPPoE client to connect?

[luisr]

I don't know if my ISP uses PPPoE. I never have to enter a user name or password to connect to the Internet. I do know the modem authenticates itself to the network with its serial number and a ISP-configured password but this occurs between the modem and the central office, the computer does nothing there as the modem connects even with the computer turned off. My user name and password for e-mail or dial-up access (to the same ISP) is different from those and not used at all during DSL authentication.

To exchange the modem I would have to purchase one and configure it for my ISP (something that I don't know how to do).