Firewalls and CU-Seeme

Mark Tsombakos (
Fri, 23 Sep 1994 09:05:15 -0400

> I would add a question # 5 to the original list, here. Due to my company's "double
> firewall" connection to the Net, I've only been able to test CU-SeeMe thus far using
> SLIP into my personal account with a local ISP (Internet Service
Provider). Does
> CU-SeeMe use any particular IP port that I might be able to have my network admin
> person let pass through our routers so that I could try this stuff over a higher
> bandwidth network connection? I'm assuming that the reason I can't get it to work
> is that whatever resources CU-SeeMe requires is/are clamped down at some point
> within our firewall setup.

I'll throw in my $.02. I'm also behind a firewall, but asked the
net-gods if they could open up port 7648 so I could use this
application. They did, after a fashion, but it still didn't work.
Why? Even after asking you kind folks which port CUSeeMe uses, I only
saw the number, 7648. I didn't mention to the network folks that it's
_UDP_ port 7648. (Ok, ok, so I'm learning!) They only opened the
TCP port. "We don't normally allow access from UDP ports. We will
raise the question of allowing this service at the next Internet
Security Meeting."


The moral: Listen to what people tell you, understand what they're
saying, and _be specific_!

(Thanks for all the replies, by the way)


>From!cu-seeme-l Fri Sep 23 09:14:29 1994
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Reply-To: mitcheec@ctrvax.Vanderbilt.Edu (Elliott Mitchell)
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From: mitcheec@ctrvax.Vanderbilt.Edu (Elliott Mitchell)
To: Multiple recipients of list <>
Subject: a novel problem?
Date: Fri, 23 Sep 1994 09:58:38 -0400

I just downloaded and began to use CU version PPC0.70b10 (the newest and
greatest yet) and an odd thing happened, which I will describe. I
connected to the Secondary Reflector at Cornell and three windows opened,
the owner of one of which asked to use audio with me.

After I turned off my internal CD player ("School Boy Crush" by the Average
White Band from Rhino Record's "In Yo' Face! The History of Funk, Volume 4
{which is actually better than coffee to get me started in the morning}) I
was able to make an excellent audio connection to the user in Germany. I
clicked on his microphone icon to establish a more private connection (also
being kinder to the internet I think).

After our discussion, he logged out of the reflector and I saw that the
microphone icons on the remaining windows were all Xed out, there appeared
to be no way I could talk to them. I quit CU and then immediately
re-started and this time the same two windows were available for audio,
although I don't usually talk to the New York skyline :{)


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| Elliott Mitchell   Vanderbilt University   Nashville, Tenn.
| I had my bases covered but the game turned out to be football...