A scalable multicast session announcement system is a key component of a group communication framework over the Internet. It enables the announcement of session parameters (like the {source address; group address} pair) to a potentially large number of users, according to each site administrator's policy. This system should accommodate any flavor of group communication system, like the Any-Source Multicast (ASM) and Source-Specific Multicast (SSM) schemes. In this paper we first highlight the limitations of the current Session Announcement Protocol (SAP) and study several other information distribution protocols. This critical analysis leads us to formulate the requirements of an ideal multicast session announcement system. We then introduce a new session announcement system called "Channel Reflector". It appears as a hierarchical directory system and offers an effective policy and scope control technique. We finally mention some design aspects, like the protocol messages and configuration structures the Channel Reflector uses.

The current telecommunication network is structured in two layers: The intelligent layer that includes Intelligent Network (IN) nodes and Operation, Administration and Maintenance (OAM) nodes, and the transport layer that includes Network Elements (NEs). The transport layer carries user Information (Iu) from end-users as well as control and OAM Information (Ic&o) from IN/OAM nodes. The quick deployment of new IN services and OAM capabilities that will need (a) flexibility and easy management, and (b) an effective handling method for searching the huge amount of data among distributed databases, will be two requirements to be satisfied. Integrating various types of Ic&o into a unique Ic&o transport network and using ATM technique as a transport technique satisfies partly the requirement (a). To completely meet both requirements, this paper proposes the following solutions:(a) Intelligent layer connections and transport layer connections should be managed independently: The necessary mapping between the Logical Destination Address (LDA) that represents the logical address of the physical entity where data are routed, combined with the Quality Of Service (QOS) type, and the ATM connection IDentifier (ID), that is to say the Virtual Channel Identifier/ Virtual Path Identifier (VCI/VPI), is provided by specific nodes (the Ic&o network Management Nodes (Ic&o MNs)) belonging to an intermediate layer, i.e., the Ic&o network management layer.(b) The widely distributed aspect of the databases also needs a very effective data handling method. This paper proposes to implement a Distributed Directory System (DDS) into both intelligent nodes and Ic&o MNs.In order to apply the DDS function to 2 functional levels, the following items are studied: First, the possible mapping of DDS functions into the intelligent node functions is proposed. Second, this paper gives an interaction scenario between intelligent nodes and Ic&o MNs, to translate the LDA/QOS type into VPI/VCI. Finally, the analysis of the mapping of LDA/QOS type into VCI/VPI at the ATM level shows that the Ic&o network based on VP backbone offers the best compromise between flexibility, complexity and cost.