Request for Question Clarification by
duncan2-ga
on
28 Oct 2002 19:00 PST
Hi jumbie,
It's possible that this question wasn't answered because it wasn't
specific enough. Are you talking about Audio conferencing, Video
conferencing or both? Is it point-to-point, or multi-user. Which
protocols are you using? H.323? What audio codecs? etc.
From my experience with H.323/netmeeting conferencing and firewalls,
you have a few options:
1) get a newer firewall that supports 'stateful inspection' of
packets; essentially you can teach the firewall to allow H.323 calls
to go through, dynamically opening and closing ports as necessary.
2) get a trusted host outside the firewall to act as an intermediary
or conferencing server; both parties call the host, and the firewall
is configured to allow h.323 traffic to that host only.
Newer firewalls are much less of a problem, but Network Address
Translation (NAT) is still a serious issue due to the defining
characteristics and specifications of the H.323 protocol. (Basically
if both end-points are NATed, you're going to have little hope of
getting H.323 to work properly).
Part of the problem with H.323 is that it randomly chooses ports
during call initiation, and so no one security rule can allow simple
firewall traversal without a large compromise in network security.
As for history of attempts, not a clue. It would be specific to your
network configuration and equipment.
