Microsoft KB Archive/277655

= XCCC: Cannot Establish an Audio-Video Conference Session =

Article ID: 277655

Article Last Modified on 10/28/2006

-

APPLIES TO


 * Microsoft Exchange 2000 Conferencing Server

-



This article was previously published under Q277655



SYMPTOMS
When you are a conferencing participant and attempt to connect to an audio-video only conference, you may receive the following error message:

An audio video connection to the Exchange Conferencing Server could not be automatically established. Either client, server, or network capabilities could not be negotiated or the conference capacity may have been reached.



CAUSE
This issue can occur if the conferencing administrator has set the conference resource's video Conference Technology Provider (CTP) to fallback to H.323. If the the conference is video only and you connect using the H.323 connectivity method, you receive the error message described in the &quot;Symptoms&quot; section.

This error message occurs because the H.323 bridge must have a data CTP associated with the conference resource to achieve H.323 fallback. If a CTP is not associated with the conference resource, the client is unable to connect.



RESOLUTION
To resolve this issue, associate a data CTP with the conference to enable H.323 fallback.



WORKAROUND
To work around this issue, upgrade conferencing participants to Windows 2000, which provides Internet Protocol (IP) Multicasting connectivity and capabilities.



STATUS
This behavior is by design.

Additional query words: XCCC xcln exch2kp2w

Keywords: kberrmsg kbprb KB277655

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.