scope:

The present document describes the architecture and protocols that are required for playing announcements in Voiceover- IP (VoIP) IPCablecom networks. Announcements are typically needed for calls that do not complete. Additionally, they may be used to provide enhanced information services to the caller. Different carrier service feature sets require different announcement sets and announcement formats.

Announcements can be as basic as fixed-content announcements (e.g. all circuits busy) or as complex as those provided by intelligent Interactive Voice Response (IVR) systems. The IPCablecom service model requires that all announcements be provisioned and signalled in a standard manner for all supported call features and use case scenarios.

The present document defines a set of signalling protocols that are used to provide announcement services within a cable network. For one of these protocols - the IPCablecom Network Call Signalling (NCS) protocol [i.3] - the present document defines two new event packages:

• a Base Audio Package;

• an Advanced Audio Package.

NOTE: There may be cases where audio server implementations are based on protocols other than that specified in the present document. If other protocols are implemented, those implementations will adhere to IPCablecom-specified architectural and functional requirements, such as security and Quality of Service (QoS), and the required features/capabilities to support interoperability. A variety of such protocols exists, including protocols such as INAP, ITU-T Recommendation H.248 [i.9] and others.

Announcement Servers, also known as Audio Servers are network components that manage and play informational tones and messages in response to events that occur in the network. Most announcements are media streams that originate from servers in the network. Some simple tones and short announcements can also reside at the MTA and in the MG.