Bosch PRAESENSA, Руководство по установке

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26 en | General installation procedures and instructions PRAESENSA
2019.11 | V1.00 | Installation manual Bosch Security Systems B.V.
4.6.1 Network topology
PRAESENSA offers great flexibility to position its networked devices across the premises. This
allows for a conventional centralized system topology, with most of the equipment in a central
19”‑rack in a technical room. But it is as easy to position equipment in smaller clusters on
different locations in order to keep loudspeaker lines short, saving on cost and reducing
power losses in the loudspeaker cabling. This is especially beneficial when expensive
fire‑resistant cables must be used. Because all system elements are network connected and
can be powered from a multifunction power supply with local battery backup power, a
decentralized system topology is easier than ever before. Call stations, positioned at operator
locations, are also network connected and even powered over Ethernet.
4.6.2 Network connector ports
The system controller has five external RJ45 network ports and acts as the root switch for the
network, supporting multiple loops.
The multifunction power supply has five external RJ45 network ports and one socket for a
Small Form‑factor Pluggable (SFP) transceiver module for a single mode or multi‑mode optical
fiber connection, to facilitate long distance connections between decentralized clusters of
devices. Two of the RJ45 network ports provide Power over Ethernet (PoE) to power a
connected call station.
Each call station has two RJ45 network connectors, each capable of taking PoE‑power, to
connect to one or two different power supplies, to allow for fail‑safe redundancy. Because of
PoE, connecting call stations in a loop-through fashion is only possible with a PoE power
source in between, e.g. a midspan PoE power adapter.
4.6.3 Audio content and device control
PRAESENSA uses OMNEO network technology. OMNEO is an architectural approach to
connecting devices that need to exchange information such as audio content or device
control. Built upon multiple technologies, including IP and open public standards, OMNEO
supports the technologies of today such as Audinate’s Dante while adopting the standards of
tomorrow, such as AES67 and AES70. OMNEO offers a professional-grade media networking
solution that provides interoperability, unique features for easier installation, better
performance and greater scalability than any other IP offering on the market.
Using standard Ethernet networking, media products that integrate OMNEO can be assembled
into small, medium and large networks that exchange studio-quality synchronized
multichannel audio and share common control systems. OMNEO’s media transport technology
is based on Audinate’s Dante, a high performance standards-based, routable IP‑media
transport system. OMNEO’s system control technology is AES70, also known as Open Control
Architecture (OCA), an open public standard for control and monitoring of professional media
network environments. OMNEO devices are fully compatible with AES67 and AES70, without
losing any functionality.
4.6.4 Network security
The OMNEO network technology includes two types of security:
–
Control security, using encryption and authentication of the TCP (OCA) control data.
– Audio security, using encryption and authentication of the audio streams.
Control security is realized via Transport Layer Security (TLS). This mechanism requires a
TCP‑link and a Pre‑Shared Key (PSK). The PSK has to be present on a device before it is
possible to start a secure connection with that device. OMNEO uses the Diffie‑Hellman key
exchange method to allow two parties that have no prior knowledge of each other to jointly
establish a shared secret key over an insecure channel. This key can then be used to encrypt