Abstract: Call admission control (“CAC”) servers in a pool are fully connected to one another. Session data received at one of the CAC servers in a pool is synchronized to each of the other CAC servers in the pool by way of the connections. Each CAC server in a first pool may also establish a connection with exactly one CAC server in a second pool. Status updates and commit data is synchronized from a CAC server in the first pool to a CAC server in the second pool. The commit data may then be synchronized to each of the CAC servers in the second pool.

Abstract: A client in a media session periodically transmits a “keepalive” message that indicates that a new amount of bandwidth is requested for the in-progress media session. A bandwidth policy service receives the keepalive message and determines whether the new amount of bandwidth can be allocated to the in-progress media session. If the service determines that the new amount of bandwidth can be allocated to the session, the service transmits a response to the keepalive message that indicates that the new amount of bandwidth has been allocated to the media session. The client receives the response and adjusts the bandwidth utilized by the in-progress session to the new amount of bandwidth.

Abstract: Call admission control (“CAC”) servers in a pool are fully connected to one another. Session data received at one of the CAC servers in a pool is synchronized to each of the other CAC servers in the pool by way of the connections. Each CAC server in a first pool may also establish a connection with exactly one CAC server in a second pool. Status updates and commit data is synchronized from a CAC server in the first pool to a CAC server in the second pool. The commit data may then be synchronized to each of the CAC servers in the second pool.

Abstract: A session bandwidth limit is specified that defines the maximum amount of bandwidth that can be allocated to a single audio or video session on a network link. Prior to establishing an audio or video session on the network link, the session bandwidth limit is consulted to determine if a requested amount of bandwidth for the session can be allocated. The session may be established if the requested amount of bandwidth does not exceed the session bandwidth limit.

Abstract: A client in a media session periodically transmits a “keepalive” message that indicates that a new amount of bandwidth is requested for the in-progress media session. A bandwidth policy service receives the keepalive message and determines whether the new amount of bandwidth can be allocated to the in-progress media session. If the service determines that the new amount of bandwidth can be allocated to the session, the service transmits a response to the keepalive message that indicates that the new amount of bandwidth has been allocated to the media session. The client receives the response and adjusts the bandwidth utilized by the in-progress session to the new amount of bandwidth.