[AG-TECH] vic fact

S.Booth spb at epcc.ed.ac.uk
Tue Nov 18 03:35:18 CST 2003

On Mon, 17 Nov 2003, Robert Olson wrote:

> >
> >Can somebody verify that the network admin was right?  If I got the wrong
> >information, please help correcting it.
> What is happening is that rat uses the same port number for the source port 
> and destination port, but vic uses a randomly-assigned port number for its 
> source port.
> I've poked a little about changing this behavior in vic, but the 
> straightfoward fixes I've tried haven't changed it; looks like it'll be 
> more important as time goes on to get this taken care of - after SC perhaps 
> I'll try to take another stab at it.

I went through somehing similar with quickbridge. 
You can work around the problem by both connecting to a quickbridge as the
recent versions use the same port for sending/receiving unicast packets. 

One thing to watch out for with firewall configurations like this is that
they are assuming a
request/response so if they pass a udp packet in the outward direction
they will accept incoming packets from the destination host/port for a
short window afterwards. With RTP data this will only work while all
parties are transmitting. If one party stops transmitting then a short
time afterwards the firewall will start blocking the icoming data
port. The control port will remain open so you will continue to see the
participants in the status window.

|epcc| Dr Stephen P Booth             Project Manager           |epcc|
|epcc| s.booth at epcc.ed.ac.uk          Phone 0131 650 5746       |epcc|

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