XCCC: Audio and Video Conferencing Do Not Work When You Use NAT (302464)


The information in this article applies to:

  • Microsoft Exchange 2000 Conferencing Server
This article was previously published under Q302464

SUMMARY

Exchange 2000 Conferencing Server may not work as expected when Network Address Translation (NAT) is used. Specifically, data conferencing works and is supported in this environment, but audio and video conferencing are not supported.

MORE INFORMATION

Exchange 2000 Conferencing Server provides a platform for real-time online conferencing that allows you to schedule and conduct online conferences with live audio and video, using either Internet Protocol (IP) multicasting or the H.323 protocol standard. Because multicasting is not generally available across the Internet, administrators may configure conferencing resources that support audio and video by enabling H.323 fallback. However, clients that join a conference when NAT is deployed are not able to receive audio and video because of the nature of address translation.

A client behind a NAT server registers its internal (non-routable) IP address in the packet that is used to negotiate the H.323 session with the Conferencing Server. Therefore, the server is unable to communicate properly with the client, and the session is not successful.
Modification Type:MinorLast Reviewed:4/25/2005
Keywords:kbinfo KB302464
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