Webcam - video works, audio does not

[Zardoz]

I just got a Logitech Pro 4000 webcam. With it came software for msn
messenger, & it proceeded to download the latest version. (6.1 I think
was the version). He also has the same webcam. He has used his
webcam's video & audio succesfully in the past, using Yahoo's
software. He uses Windows 2000 pro, while I use Windows XP.

He is the only person I have communicated with via webcam. Our video
works as well as can be expected (me dial-up, him cable), however, we
cannot get audio to work. (typing at each other works also) .

Both of us have checked out our audio in msn messenger's tool command
& both of us show audio responding & showing through yellow to red
when tested, so I do not think that is a problem.

The problem is when either one of us sends the other audio, or the
request to communicate through audio, & the other accepts, msn
messenger tries to connect, displaying the message "attempting to
connect", well, it never connects (video is still working at this
time). After many seconds have passed, I see the message in chat
"there is a problem with the computer you are trying to connect to"
(something like that anyways). We've even tried turning video off &
trying audio only, but it still won't connect.

Any feedback would be appreciated.

 

[Chris Jackson]

Are either of you using a router or a firewall? This could be blocking the
audio communication.

 

[Zardoz]

Re: Webcam - video works, audio does not

Are either of you using a router or a firewall? This could be blocking the
audio communication.
--
Chris Jackson
Software Engineer
Microsoft MVP - Windows Client
Windows XP Associate Expert

Well of course, we both are... What sane person would not use a
firewall nowadays?

XP has the firewall built right into the software, & I have it checked
yes. My friend uses Windows 2000 Pro, but I do not know what firewall
he uses. (me - dial up account, him - cable. No networks or anything
like that).

Upon further investigation, I found that he had the same problem with
someone else using Yahoo's Messenger. (picture ok, sound not).

What I need to do is find someone that has the same set-up as me & see
if we work together, so I can determine who's got the problem.

But I would find it interesting that a microsoft product (msn
messenger) would want you to disable the built in firewall of another
microsoft product (Windows XP) to get a webcam to work - all 3 the
latest stuff (both software products & the webcam).

Does anyone out there have a firewall in place & have a webcam working
reight? (voice & picture?) If webcams require a person to disable
firewalls to get them to work, what good are they?

 

[Chris Jackson]

I was in no way suggesting that you shouldn't be using a firewall. Rather,
it depends on what you are using as to how you can approach the problem. In
order to make a connection between the two machines, you have to be able to
connect to one another somehow. If you have a firewall or router up, you
have to allow that traffic to come in. If you are using a NAT device as your
edge device, then you have to know what machine to forward to when you get a
packet targeting a particular port.

So, for audio communication, your speech is digitized, bundled up in
packets, and shot across the wire to your friend, targeting a particular
port number. If that port is closed on the firewall, then it just bounces
right off. The solution to this is not to disable the firewall, but to open
up that one port. The problem is, that port is dynamic, so you can't just
open up a single one, because you never know what one that is going to be.

Next up, say one of the devices you are using is a router that uses NAT.
What this means is that there can be multiple computers behind this router
all using the same public IP address. So, you try to send a packet to a
particular port on your friend's computer, but he has a NAT device, then it
hits the firewall (the only public address) and then has no idea which
computer to send that packet to. As a result, that packet gets dropped.
Again, the solution isn't to forward every port, but just the ports you
need. And, again, the problem is that this is dynamic on Messenger's voice
communication.

So, how do you avoid just leaving a slew of ports open to the whole world?
One solution is UPnP. If you have a firewall or router that supports UPnP,
an application can "talk" to it, and let it know what port it needs to open,
and what machine it needs to forward it to. The XP firewall supports UPnP,
so if you go into the properties of the firewall while you are having a
voice chat, you will see that it has automatically opened up several ports
for you, thanks to UPnP. Many Linksys routers (with recent firmware) also
support UPnP, if that feature is enabled.

In other words, you have a tough problem to solve, and it depends on exactly
what software and devices sit between you two as to how to approach the
solution, if there even is one.

 

[Chris Lemon]

Many Linksys routers (with recent firmware) also support UPnP, if
that feature is enabled.

Is the fact that I now have enabled that feature on my Linksys router the
reason why I now have an "Internet Gateway" section in my Network
Connections, with an "Internet Connection" icon beneath it? If so, is there
a KB article I could read that explains more about this?

 

[Chris Lemon]

Many Linksys routers (with recent firmware) also support UPnP, if
that feature is enabled.

Is the fact that I now have enabled that feature on my Linksys router the
reason why I now have an "Internet Gateway" section in my Network
Connections, with an "Internet Connection" icon beneath it? If so, is there
a KB article I could read that explains more about this?

 

[Zardoz]

I was in no way suggesting that you shouldn't be using a firewall. Rather,
it depends on what you are using as to how you can approach the problem. In
order to make a connection between the two machines, you have to be able to
connect to one another somehow. If you have a firewall or router up, you
have to allow that traffic to come in. If you are using a NAT device as your
edge device, then you have to know what machine to forward to when you get a
packet targeting a particular port.

Thanks for your reply. I found the following post in a different
thread that is only a few posts down from the one we're in. Same
problem mentioned (video ok, no audio). It suggests with my set-up
(Logitech Quickcam Pro 4000) & messenger 6.1 I should be able to
connect fine with my Windows XP built-in firewall engaged.

From (e-mail address removed) Wed Jan 07 19:46:13 2004