Understanding how Communication Manager handles announcements helps with questions of load-balancing announcement traffic. Communication Manager supports up to 3,000 announcements across the enterprise. Each of as many as 10 integrated announcement circuit packs, H.248 gateway virtual VAL source, and Avaya Aura® Media Server is limited to 256 announcements.

You can have up to 250 virtual VAL sources per system, and Avaya Aura® Media Server (MS).

Each Virtual VAL source has 64 playback ports (with 20 minutes storage capacity). Initially, each caller that is to hear a non-barge-in announcement on that source is connected to an available port until each port has one caller connected. Initially,64 callers can be hearing an announcement from a single virtual VAL source. The same announcement can be playing from multiple ports, each starting at a different time. Once all ports are busy playing announcements, subsequent callers that are to hear an announcement residing on that circuit pack/source are queued for that source.

Communication Manager queue size over all integrated announcement sources is 4,000 callers (duplex and simplex servers/S8300E or S8300D server). When a port becomes available, all callers (up to 1,000) waiting in the queue for a specific announcement on that source are connected to the available port to hear the announcement play from the beginning on a first-in, first-out basis.

The measurements announcements command can be used to monitor the system and help determine burst conditions, providing efficient load balancing of the traffic.