[VPN] MSN Messenger Video Conference
DePriest, Jason R.
jrdepriest at ftb.com
Mon Mar 31 17:25:42 EST 2003
If it is using the same underlying technology as Netmeeting (which I imagine
it is), here are some instructions I received from a vendor about two years
ago and getting it working.
Here are the directions:
Setting Up NetMeetings Through a Firewall
When you use NetMeeting to establish a connection over the Internet,
NetMeeting uses several IP ports to communicate with other meeting
participants. If you use a firewall to connect to the Internet, the
must be configured so that the ports used by NetMeeting are not blocked.
NetMeeting uses the following Internet Protocol (IP) ports:
389 Internet Locator Server [Transmission Control Protocol (TCP)]
522 User Location Server (TCP)
1503 T.120 (TCP)
1720 H.323 call setup (TCP)
1731 Audio call control (TCP)
Dynamic H.323 call control (TCP)
Dynamic H.323 streaming [Realtime Transport Protocol (RTP) over User
Datagram Protocol (UDP)]
To establish outbound NetMeeting connections through a firewall, the
firewall must be configured to do the following:
* Pass through primary TCP connections on ports 522, 389, 1503, 1720
* Pass through secondary UDP connections on dynamically assigned
NOTE: Some firewalls are capable of passing through TCP connections on
specific ports, but are not capable of passing through secondary UDP
connections on dynamically assigned ports. When you establish NetMeeting
connections through these firewalls, you are unable to use the audio
features of NetMeeting.
In addition, some firewalls are capable of passing through TCP connections
on specific ports and secondary UDP connections on dynamically assigned
ports, but are not capable of virtualizing an arbitrary number of internal
IP addresses, or are not capable of doing so dynamically. With these
firewalls, you are able to establish NetMeeting connections from computers
inside the firewall to computers outside the firewall and you are able to
use the audio features of NetMeeting, but you are unable to establish
connections from computers outside the firewall to computers inside the
The H.323 call setup protocol (over port 1720) dynamically negotiates a
port for use by the H.323 call control protocol. Also, both the audio call
control protocol (over port 1731) and the H.323 call setup protocol (over
port 1720) dynamically negotiate User Datagram Protocol (UDP) ports for
by the H.323 streaming protocol, called the real time protocol (RTP). In
NetMeeting, two ports are determined on each side of the firewall for
and video streaming. These dynamically negotiated ports are selected
arbitrarily from all ports that can be assigned dynamically.
NetMeeting directory services require either port 389 or port 522,
on the type of server you are using. Internet Locator Servers (ILSs),
support the lightweight directory access protocol (LDAP) for NetMeeting
or later, require port 389. User Location Servers (ULSs), developed for
NetMeeting 1.0, require port 522.
> -----Original Message-----
> From: Seth Robinson [mailto:seth.robinson at maine.edu]
> Sent: Monday, March 31, 2003 2:48 PM
> To: vpn at lists.shmoo.com
> Subject: [VPN] MSN Messenger Video Conference
> Hey Everyone!
> I am trying to set up video conferencing between two of our offices
> through MSN Exchange Client. When I initialize a video conversation
> with someone else, it always works, but when they try to
> initialize it,
> it doesn't. The computers do not connect. This happens with any
> feature of MSN that requires the two computer to connect.
> We are using Sonicwall Hardware. We have a pro-200 where I am, and a
> SOHO 2 and 3 at the other branches. We have a box to box VPN up.
> What I'm wondering is if I need to do something to the config to make
> all the ports that MSN uses work both ways. I know that for video
> conferencing the h.323 protocol is used, but I'm wondering if there is
> something special we need to set up to make that work both
> ways over the
> Seth R.
> VPN mailing list
> VPN at lists.shmoo.com
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