Re: Are there other protocolls then UDP?

Alain Caillet (acaillet@dow.on.doe.CA)
Thu, 9 Feb 1995 14:03:39 -0500


Patrick Steiger <steiger@ubilab.ubs.ch> said:

>I work in a Swiss bank. I installed CU-SeeMe and it works fine -
>internally. For safety reasons we have a firewall suppressing all UDP
>trafic from and to the outside. My network administrator told me, that the
>only possibility to get connected to an external reflector would be using
>another protocol? Is there any chance?

Patrick, I have a similar problem but not with CU-SeeMe.
First UDP:

UDP protocol is connectionless and therefore fast. But it is
used by NSF (Network File System) internally by network.
So since it does not need to establish a client server
connection, it presents a security problem and is usually
block by firewall in the outside/inside direction.

I now have a question. our firewall does not block
CU-SeeMe packets but block Talk packet. Does anyone
has an explanation? Which are the Talk port (originator
responder)
Are CU packets different to fool some firewall or firewall
configured to block all port below a certain number?

An answer, even technical, would me immensely appreciated.

Thanks in advance, Alain

Alain Caillet, Sr Meteorologist <acaillet@dow.on.doe.ca>
<http://www.dow.on.doe.ca/climate/climate.shtml>
<> A.E.S. Downsview <><> The validity of a science ...
<> Ontario CANADA <><> ... is its ability to predict