ESTA E1.33 PDF

Document Scope

This standard specifies how RDM is implemented on IP networks and how gateways between IP and DMX512-A media operate. The following protocols are specified to achieve this: RPT, EPT, Broker Protocol, and LLRP.

RPT is used to carry RDM messages over IP networks, including propagation to and from connected DMX512-A networks. RPT provides for RDM Controller functionality that resides on IP networks. RPT specifies how to use RDM messaging to configure and monitor IP and DMX512-A equipment that supports it. Using DMX512-A based Controllers to configure and monitor IP based RDM functionality or to tunnel RDM through IP networks from one DMX512-A network to another, while not explicitly disallowed, is outside the scope of this standard.

LLRP is used to configure IP settings so that E1.33 equipment achieves connectivity.

The Broker Protocol provides reliability and scalability to RPT communication. It defines its own set of messages to make connections and facilitate discovery.

EPT provides a minimal wrapper for sending non-RDM data between Components through a Broker. The format of the data carried by EPT is not defined in this standard.

The protocols in this standard are intended to be used in networks up to the scale of large private networks. They are not intended to be used across the public Internet.

This standard places no restriction on the IP addresses used within a system.

Low-Level Recovery Protocol (LLRP)

LLRP is a multicast protocol that provides basic IP configuration. It has its own limited discovery mechanism, which does not require a valid IP configuration. LLRP is intended as a light-weight protocol, and as such it is not designed for scalability or for discovery and normal operation on a large network.

LLRP can be used for the initial system configuration of Components. It provides a low-level mechanism for discovering and configuring parameters of network hosts. Such parameters include IP and basic RDMnet configuration settings.

LLRP Targets expose these parameters for configuration and respond to discovery requests from LLRP Managers. Once an LLRP Manager has discovered one or more LLRP Targets, it can use LLRP to send RDM commands to the LLRP Targets to retrieve or change those parameters.

LLRP does not provide a complete RDM-over-IP solution. It is not scalable or routable. It is not to be used for RDM messages beyond the minimum message set required to facilitate configuring a Component for connection and operation within an E1.33 network.

Broker Protocol

The Broker Protocol enables the scalability and multi-controller functionality of RDMnet. It uses a central server called a Broker to handle discovery, maintain the state of the system and facilitate message routing. The Broker routes messages between a set of other Components, which are referred to as Clients. The Broker Protocol contains a small set of messages that facilitate Client connection and discovery of other Clients.

RDM Packet Transport (RPT)

RPT transports RDM messages over IP and supports a multi-controller environment. RPT equipment relies on initial configuration by LLRP, or by alternative means, to operate correctly. The RPT protocol is designed to scale communication to tens of thousands of Components via use of the Broker Protocol. The ultimate limit to the size of a system is determined by the infrastructure and not by the protocol itself.

Clients implementing RPT conform to one of two roles: Controllers, which originate RDM GET_COMMAND or SET_COMMAND requests on an IP network, and Devices, which respond to RDM GET_COMMAND or SET_COMMAND requests and may represent one or more RDM responders. Controllers and Devices use RPT to provide an addressing and encapsulation layer for RDM commands and responses. RPT requires a Broker to deliver messages between Controllers and Devices.

In a complex networking environment, there is not a one-to-one correspondence between network hosts and the processes which are sending or receiving data. It is possible for a single computer to run multiple, independent RPT applications.

Extensible Packet Transport (EPT)

EPT allows non-RDM data to be transmitted using a Broker. It uses a simple message format which addresses Components solely by their CID, and allows manufacturer-defined data to be transmitted between Components free from the message format and behavioral restrictions of RDM.