ISO/IEC 16512-2:2016 specifies the relayed multicast protocol part 2 (RMCP-2), an application‑layer protocol that constructs a multicast tree for data delivery from one sender to multiple receivers over an IP-based network, where IP multicast is not fully deployed. RMCP-2 defines relayed multicast data transport capabilities over IP‑based networks for simplex group applications.

This Recommendation | International Standard specifies the following:

a) descriptions of the entities, control and data delivery models of RMCP-2;

b) description of the functions and procedures of multicast agents (MAs) to construct a one-to-many relayed data path and to relay data for simplex communication;

c) description of the security features of the basic RMCP-2; and

d) definitions of messages and parameters of the basic RMCP-2 and secure RMCP-2.

Annex A defines a membership authentication procedure for use with the secure RMCP-2. Annex B provides a method for sharing information among session managers (SMs) when multiple SMs are used. Annexes C‑G provide informative material related to RMCP-2. Annex H contains an informative bibliography.