Crestron DigitalMedia NVX Series Guide

DigitalMedia™ NVX Series System
Design Guide
Crestron Electronics, Inc.

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Design Guide – DOC. 7977CContents •i
Contents
Introduction 1
How NVX Works 1
NVX Design 2
NVX Endpoint Design .................................................................................................... 2
SFP-1G Modules .................................................................................................... 4
XIO Director ............................................................................................................ 5
Endpoint Bandwidth Design and Management ....................................................... 5
Endpoint Design Considerations ............................................................................. 6
NVX System Design....................................................................................................... 8
NVX System Design Overview................................................................................. 8
Network Topologies .............................................................................................. 10
Network Multicast Functionality............................................................................. 13
Network Security................................................................................................... 14
Network Design Considerations ............................................................................ 14
NVX System Installation 16
NVX Endpoint Installation............................................................................................. 16
NVX Network Installation.............................................................................................. 19
Crestron Service Provider Handoff............................................................................... 20
Case Studies 21
Case Study #1: Community College 4K AV Distribution via Network ........................... 21
Case Study #2: 4K Residential AV Distribution Network .............................................. 23
Case Study #3: 4K AV Distribution over Fiber.............................................................. 25
Glossary 27

Design Guide – DOC. 7977C DigitalMedia NVX Series System •1
DigitalMedia NVX Series System
Introduction
This document is provided as an aid to the design and installation of networked video and
audio distribution systems using the Crestron®DM-NVX series line of products.
NVX is the world’s first digital video distribution system capable of switching thousands of
4K video sources and displays at 60 frames per second with full 4:4:4 color sampling, High
Dynamic Range (HDR), and low latency over long distances using flexible commodity
Gigabit Ethernet fiber and copper network infrastructure.
With additional features for security, web-based configuration, local end-point video source
switching, video wall, remote USB peripheral control, and analog audio source switching
and playout, NVX is ideal for any application where scalability and flexibility with lower
deployment cost per endpoint is required.
For additional details on functionality and configuration, refer to the DM-NVX Series
Supplemental Guide (Doc. 7839) at www.crestron.com/manuals.
How NVX Works
Video distribution technology has evolved considerably since the emergence of analog video
switching and amplification. Digital video carried over interfaces such as HDMI®technology
has enabled high-quality experiences for average consumers. Despite this, inherent
limitations from the perspective of scale, coverage distance, installation flexibility, and
features persist because of the extreme high bandwidth imposed by uncompressed video
interfaces such as HDMI and HDBaseT®technology, particularly at 4K resolutions. Yet the
emergence of high-speed commodity network hardware and low-cost computing power
has revolutionized long-distance, high-quality streaming video distribution on both private
networks and the public Internet.
The cornerstone of NVX’s ability to leverage Gigabit Ethernet infrastructure is the JPEG
2000 compression format. Unlike traditional JPEG or MPEG that breaks images down into
blocks to remove visually redundant information, JPEG 2000 uses a method called
wavelet-based compression. This type of compression, in conjunction with the high bit rates
afforded by Gigabit Ethernet, recreates images with visually imperceptible losses in quality,
even when compared to an uncompressed version of the original.
NVX can easily switch and move many video sources using Gigabit Ethernet infrastructure,
resulting in considerable cost savings versus moving uncompressed lossless 4K 60 frames
per second 4:4:4 video. More significantly, this bandwidth savings allows NVX to scale up
the number of video sources and displays to much higher levels than is possible with
uncompressed sources, with no additional latency (due to the close integration with the
scaler during the decoding process).

2•DigitalMedia NVX Series System Design Guide – DOC. 7977C
NVX sends and receives video and audio by encapsulating it in an MPEG-2 Transport
Stream (TS), then sending that transport stream using Real-time Transport Protocol (RTP)
and Real-time Streaming Protocol (RTSP) over multicast Universal Datagram Protocol
(UDP). This allows NVX to distribute video from one source to thousands of receivers on the
network without resorting to inefficient unicast point-to-point links that would make
high-quality, multipoint video distribution impossible.
Every NVX endpoint is dynamically configurable as either an output transmitter (encoder) or
a receiver (decoder), using stand-alone endpoints as well as add-in cards in an NVX card
chassis for denser aggregation of inputs and outputs.
NVX Design
Designing a network for NVX requires a concerted effort in gathering information and
planning to implement correctly. This design guide assists the system designer in
understanding the implications of NVX functionality on endpoints and the network.
Throughout this process, ensure that the interaction between designer, installer,
programmer, and end user is considered in all design decisions.
NVX Endpoint Design
The basic building block of an NVX system is the encoder and decoder endpoint. There are
two primary types of endpoints available to the designer: stand-alone endpoints and
chassis-based cards. Each endpoint is capable of operating as an encoder or as a decoder
at a given time; specifically, one input or one output of an NVX endpoint is available as a
TS/RTP/RTSP/UDP stream to and from one or more NVX endpoints.
Networking infrastructure is essential to NVX functionality, as all endpoints must connect to
a purpose-designed nonblocking, multicast-enabled switched network in order to function
correctly. The selection of appropriate network infrastructure components is essential to
successful NVX implementations that can be reconfigured and maintained upon
deployment.
NVX Endpoint Hardware Overview and Features
There are four models of DM®NVX hardware as follows:
•The DM-NVX-350 and the DM-NVX-351 are stand-alone endpoints with IR and
serial control, discrete device console connections via RJ45 and USB, and manual
setup and reset buttons.
•The DM-NVX-350C and the DM-NVX-351C are card-based endpoints without IR
and serial control that are used in conjunction with the DMF-CI-8 8-card chassis for
sources in close proximity to a rack or for high endpoint density applications.
The DM-NVX-351 and DM-NVX-351C are also capable of downmixing a multichannel audio
source carried over HDMI.

Design Guide – DOC. 7977C DigitalMedia NVX Series System •3
DM-NVX-350 and DM-NVX-351 Front Panel
DM-NVX-350 and DM-NVX-351 Rear Panel
DM-NVX-350C and DM-NVX-351C Front View
All endpoints, stand-alone or card-based, have the following physical connectivity:
•Two switchable local HDMI inputs for 4K 60fps 4:4:4 HDR video and multichannel
audio
•One local HDMI output for 4K 60 fps 4:4:4 HDR video and multichannel audio
•One analog stereo balanced line-level input and output audio port, capable of local
insertion of audio, replacement of HDMI source audio, or playout of audio
•Two RJ45 Gigabit Ethernet ports capable of 330 ft (100 m) distances over shielded
Cat 5e/6/6a cable
•One SFP Gigabit Ethernet port for optional optical connection using Crestron
SFP-1G transceiver modules
•One USB 2.0 host port for connecting a USB host, such as a PC
•One USB 2.0 device port for connecting keyboards, mice, and other peripherals
DM-NVX Hardware Model Differences
Product Form Factor Audio
Downmix
Card Chassis
Required
IR Out Serial Out
DM-NVX-350 Stand-alone No No Yes Yes
DM-NVX-350C Card No Yes No No
DM-NVX-351 Stand-alone Yes No Yes Yes
DM-NVX-351C Card Yes Yes No No

4•DigitalMedia NVX Series System Design Guide – DOC. 7977C
Other key features available on all NVX hardware models include the following:
•Integrated Security: Every NVX endpoint integrates security features, including
802.1x using TLS or MS-CHAP v2 authentication, Active Directory®service support
for endpoint management, audio and video stream encryption, secure Crestron IP
device control, and secure device console access.
•CEC Control: Consumer Electronic Control messages can be passed between
endpoints, allowing for easy control of source and display devices that support
CEC.
•USB Routing: USB 2.0 may be routed from one NVX endpoint to another,
independently of video and audio routing. One device must be configured as a USB
host while the other device must be configured as a USB device port.
•3D Surround Audio Support: Endpoints can pass through audio for 3D speaker
configurations, as well as traditional 5.1 and 7.1 multichannel surround audio, with
lossless audio support; a DM-NVX-351 or DM-NVX-351C is required for generating
a stereo downmix if required.
•Secondary Audio: Encoders can generate a secondary audio stream that may be
routed independently of the primary AV stream. The secondary audio stream is
stereo LPCM only. If primary audio is multichannel content, a DM-NVX-351 or
DM-NVX-351C is required to downmix for the secondary audio stream.
•LAN Port Switch: A built-in three-port LAN switch is connected to the two RJ45
and one SFP module cage, enabling daisy chaining of endpoints and control of
third-party devices in addition to primary NVX video stream I/O.
•Power-over-LAN: An RJ45 LAN port is provided with built-in Power-over-LAN
power injection to provide power directly to an end device without an external
power supply, and compatible with the DM-PSU-ULTRA-MIDSPAN.
•Video Wall: Up to 64 displays can be daisy chained across endpoints to provide
multi-display video wall capability, with each endpoint providing fully customizable
bezel compensation and zoom on any part of the source video.
For additional details on functionality and configuration, refer to the DM-NVX Series
Supplemental Guide (Doc. 7839), the DM-NVX-350/DM-NVX-351 DO Guide (7799), and the
DM-NVX-350C/DM-NVX-351C DO Guide (7975).
SFP-1G Modules
The SFP-1G family of modules are specifically designed for NVX to be able to enable
additional gigabit network connectivity options for endpoints. While not technically required
for endpoint functionality, SFP-1G modules enable fiber connectivity at much greater
distances than traditional copper.
The available Crestron-certified SFP-1G modules include the following:
•SFP-1G-SX: 850 nm multimode fiber connections up to 1640 ft (550 m) over LC-
terminated OM3 or OM4 fiber
•SFP-1G-LX: 1310 nm single-mode fiber connections up to 6.2 mi (10 km) using
LC-terminated G.652 fiber
•SFP-1G-BX-U: 1310 nm/1490 nm single-mode fiber uplink connections up to 6.2
mi (10 km) using LC-terminated G.652 fiber
•SFP-1G-BX-D: 1310 nm/1490 nm single-mode fiber downlink connections up to
6.2mi (10 km) using LC-terminated G.652 fiber

Design Guide – DOC. 7977C DigitalMedia NVX Series System •5
SFP-1G Modules
For each endpoint, the connectivity options and distance requirements will determine the
appropriate module to install.
XIO Director
Older pre-NVX digital video switch products did not make use of external network
equipment in the video switching path, opting instead to handle such switching in a
centralized card-based chassis and switch matrix. Due to the complexities of network video
management, and to bridge the gap between traditional AV designers and more
network-oriented AV designers and IT staff, XIO Director provides a comprehensive NVX
configuration and signal routing tool.
Crestron XIO Director's web-based interface emulates a traditional hardware-based
interface that allows users to automatically discover, configure, and route signals in an NVX
network. XIO Director also offers domain grouping of individual subsystems, custom
endpoint naming and search, XML-based device map file import and export for rapid
configuration of multiple endpoints, along with logging, diagnostics, and SNMP messaging
support for easy administration of NVX networks.
For additional information on XIO Director, please contact a Crestron sales representative.
Endpoint Bandwidth Design and Management
A single DM NVX network link can carry the following data streams:
•Primary Audio/Video stream: This is the video and audio from an HDMI input
(or inserted via the audio line in the port) that is encoded and sent to the network
for decoding by a remote endpoint.
•Secondary audio stream: Every encoder may generate a secondary audio stream
that may be sent independently of the primary AV stream.
•USB device and host traffic: This is USB data from the NVX device or host port.
•Other Ethernet traffic: This traffic includes control data as well as data from NVX
network ports connected to third-party devices such as displays or cameras, as
well as network protocol traffic such as DHCP, DNS, or RADIUS for 802.1x.
The default settings should be sufficient for most installations. They may, be adjusted to
accommodate unique situations. Since USB 2.0 can support up to 480 Mbps of traffic, this
exceeds the default bandwidth reservations in the forward direction and may need to be
adjusted for high-bandwidth devices. Devices such as keyboards and mice can consume
anywhere between 0.1 Mbit/s sustained and 12 Mbit/s peak, whereas mass storage and
web cameras can sustain up to 100 Mbit/s or more and peak at the USB 2.0 limit of 480
Mbit/s. It is recommended to contact the manufacturer of the USB device to confirm both
the sustained and peak bandwidth of the device to be connected.

6•DigitalMedia NVX Series System Design Guide – DOC. 7977C
Ethernet bandwidth ratings are bidirectional, so full USB 2.0 bandwidth is supported in the
reverse direction. Consider an NVX installation in which video from a PC is encoded and
sent to a decoder at a display, and in which a high-bandwidth USB camera at the display is
sending USB video back to the PC. While the sum of all traffic in this case may exceed a
gigabit, the traffic in each direction is less than one gigabit and no bandwidth issues will
exist.
Bidirectional Bandwidth under 1 Gbps Example
Conversely, an encoder that attempts to send 900 Mbps video and 480 Mbps USB 2.0
traffic will exceed the maximum network link bandwidth of 1 Gbps and fail.
Failed Link with Required Bandwidth Greater than 1 Gbps Example
For additional information on bandwidth management and configuration settings, refer to
the DM-NVX Series Supplemental Guide (Doc. 7839).
Endpoint Design Considerations
With the basic tools for NVX endpoints available, the designer must carefully consider a
number of factors for each endpoint to implement an optimal configuration for the
installation. The design considerations include the following:
•If rack-mount sources are required or a high density of endpoints are in proximity to
each other in distance, use DM-NVX-350C or DM-NVX-351C card versions of the
endpoints instead of the DM-NVX-350 or DM-NVX-351 stand-alone endpoints.
•If simultaneous stereo downmix alongside multichannel audio output is required,
use DM-NVX-351 or DM-NVX-351C instead of the DM-NVX-350 and DM-NVX-
350C.

Design Guide – DOC. 7977C DigitalMedia NVX Series System •7
•Follow the guidelines for cable types as specified in TIA/EIA-568 for choosing and
certifying cables in an NVX installation.
The following table provides guidelines on some of the primary network connectivity
options that may be used at the endpoint based on total distance.
Primary Network Connectivity Guidelines
Distance /
Connection
<100m <550m <10km
RJ45 Cat5e
Cat6
Cat6a
Cat 7
- -
SFP-1G-SX OM3 MMF
OM4 MMF
OM3 MMF
OM4 MMF
-
SFP-1G-LX G.652 SMF G.652 SMF G.652 SMF
SFP-1G-BX-U G.652 SMF G.652 SMF G.652 SMF
SFP-1G-BX-D G.652 SMF G.652 SMF G.652 SMF
•The DM-NVX-350 and DM-NVX-351 provide IR and serial control ports to control
in-room devices as a courtesy feature. Adding a Crestron control processor (such
as a PRO3 or AV3) is a necessity in a design, however, if IR and serial ports are
used anywhere in the design, or if relay I/O or Cresnet®device control is required.
•While both USB host and USB device ports are available on all NVX endpoints, only
one of these ports is capable of use at a time. The USB port can instead be routed
to a different endpoint than the video and be opposite in direction to the video
traffic to maximize the use of the 1 Gbps link in both directions.
•Although typically USB ports are used for low-bandwidth devices such as
keyboards and mice, high-bandwidth devices such as cameras and storage can
have an impact on overall video bandwidth. For additional information on how to
manage high-bandwidth USB devices and the direction of bandwidth consumption,
refer to “Endpoint Bandwidth Design and Management” on page 5.
•If additional HDMI inputs are required for local switching at the endpoint within
typical HDMI cable distances of 15 ft (5m), consider using other Crestron solutions
in conjunction with the endpoint, such as the Crestron DM and DMPS families of
products.
•If an endpoint will be dynamically reconfigurable as both an encoder and a decoder,
it is critical to ensure that any external analog balanced audio connection is fixed in
configuration and is not used for both input and output. Dependence on external
device control via serial or IR ports on the endpoint should similarly be considered.
•In many NVX installations, a programmer must configure specific control surfaces
and additional switch options at endpoints, such as Crestron touch screens and
local HDMI switches, so be sure to consider such options from the beginning for
first-time success.

8•DigitalMedia NVX Series System Design Guide – DOC. 7977C
NVX System Design
All NVX systems require an appropriately designed and provisioned Ethernet network to
function correctly. Even smaller network implementations can require an experienced
network designer depending on the overall project scope. Proactively gathering
requirements and documentation, coordinating with customer IT staff, and completing
network design prior to site work will result in efficiently designed and deployed NVX
installations.
NVX System Design Overview
Design NVX networks to isolate network traffic on network segments specifically architected
for NVX. This may be accomplished either physically using separate infrastructure or virtually
using Virtual Local Area Network (VLANs) or Multi-Protocol Label Switching (MPLS). The
primary role of NVX network segments is to carry NVX multicast streams as well as NVX
control and ancillary traffic.
A secondary design decision must also be made as to where other Crestron network
devices will be located relative to network infrastructure, and particularly whether such
devices will coexist on the same segment as the NVX or another segment that has traversal
capabilities (but not multicast enabled) to the NVX segment.
Other non-NVX networked AV devices may be placed on the NVX network segment so long
as their bandwidth requirements are understood relative to the NVX endpoint bandwidth
requirements.
An NVX device can have up to three addresses.
•The first address is for control of the device as well as access to the web
configuration interface and console.
•Two additional addresses are also required for multicast corresponding to the
primary multicast stream of audio and video, and to the secondary multicast stream
for secondary audio.
Both multicast addresses must be set manually during endpoint configuration. It is
therefore important to assign even-numbered IP addresses for the primary IP
multicast stream since the secondary audio multicast stream address will be
assigned a value of one higher than the primary IP multicast stream address by the
endpoint.
The NVX network segment needs to receive network services, including DNS, DHCP, Active
Directory, and RADIUS. Coordinate with IT staff to provide access to these services and to
create the proper traversal rules to the NVX network segment.

Design Guide – DOC. 7977C DigitalMedia NVX Series System •9
Network Segmentation along Logical Boundaries
One ofthe key advantages tonetwork video distribution is that any encoder may be routed
to anydecoder. For traditional circuit-switched systems such as HDBaseT, routes are
limited bythe size ofthe matrix switch. Aproperly designed andconfigured network can
support thousands ofendpoints with the ability to route any source to any destination.
The concept of a nonblocking architecture isthe core design tenet that enables this
flexibility. Anonblocking system hasenough data bandwidth on all links to support all
connected endpoints without any routing bottlenecks. Blocking must be considered at both
the switch level andthe network design level. NVX network switches must have enough
switch fabric bandwidth to support full nonblocking bidirectional gigabit bandwidth on all
ports simultaneously. While this is a common feature in most enterprise-grade gigabit
network switches, it should not be assumed that a switch is nonblocking norconfigured as
such.
Most NVX installations require multiple network switches, due to either system size or
physical layout. In these cases, NVX devices connect toGigabit Ethernet ports, but
switches are connected together with higher-bandwidth ports known as uplinks. It is
strongly recommended that the bidirectional uplink bandwidth be sufficient to handle traffic
from all connected NVX devices. For network design purposes, assume that each NVX link
consumes the full gigabit of link bandwidth.
Consider the example of astandard 48-port Gigabit Ethernet switch with 40 Gb (orfour
10 Gb) uplinks that are readily available on the market. Since each NVX endpoint consumes
one gigabit of bandwidth, this switch can support up to forty NVX devices in anonblocking
fashion. Ifmore devices are connected, the uplink becomes a bottleneck, introducing the
potential for difficult-to-diagnose blocking problems.

10 •DigitalMedia NVX Series System Design Guide – DOC. 7977C
Network Topologies
Devices such as NVX endpoints, control processors, touch screens, servers, personal
computing devices and the like are connected directly to network switches. In a typical large
network with multiple layers of switch hierarchy, these devices will be situated at the
network’s edge. The network edge switches are often (subsequently) connected via uplinks
to other switches and routers to aggregate traffic from the network edge and form the
network’s core. The relationships between network switches and their interconnection to
each other define the network’s topology.
The NVX network designer must have a thorough understanding of network architecture
and topology for a successful NVX deployment. The choice of topology, reuse of existing
infrastructure and equipment, the number and specific needs of endpoints, and the level of
redundancy will be the main drivers of network deployment cost and maintenance within the
facility.
Regardless of topology, the following general rules apply for sizing network switches in
terms of switch fabric nonblocking bandwidth:
•The network core must support a nonblocking bandwidth and port speed equal to
one gigabit multiplied by the lesser of either the total number of anticipated encoder
endpoints or the total number of anticipated decoder endpoints, plus the number of
discrete USB extenders.
•The network edge must support a nonblocking bandwidth and uplink speed equal
to one gigabit multiplied by the greater of either the total number of anticipated
encoder endpoints or the total number of anticipated decoder endpoints, plus the
number of discrete USB extenders.
Star
The default recommended network topology is a star, which has a hub-and-spoke
appearance that connects to the NVX endpoint and other devices through a single switch.
The star topology using a fully nonblocking switch allows any combination of one or more
endpoints to connect to any other combination of endpoints. It also more easily allows the
network to grow beyond a single switch if the uplink in the switch supports the maximum
specified bandwidth.
For small NVX systems that employ only one network switch, use a nonblocking switch so
that there is no opportunity for a bottleneck. Star topologies can accommodate very large
NVX installations by using large modular switch frames.
Star Network Using a Nonblocking Switch

Design Guide – DOC. 7977C DigitalMedia NVX Series System •11
Tree
A tree network is a combination of more than one star network such that many stars exist
on a core-switching infrastructure.
The tree network allows a failure in one part of the attached star networks without widely
affecting the other star networks in turn. The core network denoted by the larger network
switch can be configured for the purposes of redundancy and scalability as the network
designer sees fit. This normally means the use of more than one switch per the network
designer’s requirements.
Tree Topology Using Nonblocking Switches on a Core Network
Daisy Chain
While not a topology per se, daisy chaining is a deployment methodology that NVX
endpoints support which is appropriate only for specific deployment applications such as
video walls or jury boxes where all displays receive the same video source as the first NVX in
the chain.
For video wall applications and any application where displays will be viewed near to each
other and which share the same source, up to sixteen endpoints can be daisy chained
together. Larger video walls should be divided on individual daisy chains no longer than
sixteen endpoints.
For applications such as information, signage where more than one display will be readily
viewable concurrently and not dependent on viewing of another display in the daisy chain,
up to sixty-four endpoints can be daisy chained together.

12 •DigitalMedia NVX Series System Design Guide – DOC. 7977C
Daisy Chain Network Configuration for 3x3 Video Wall
Daisy Chain Network Configuration for Twelve-Person Jury Box
Due to limited bandwidth for audio and video, using USB host or device functionality on a
daisy chained endpoint is not recommended. For maximum flexibility and the ability to
reconfigure video walls with multiple sources, connect NVX endpoints directly to switches
rather than use a daisy chain.
Other Topologies and Network Functionality
There are other valid deployment topologies for NVX, such as ring and mesh. These
deployments require project-specific discovery, engagement of the customer’s IT staff, and
advanced configuration of network switch beyond the scope of this guide.
For projects using advanced topologies for deployments, a networking professional with
vendor-specific knowledge of the network hardware being deployed must be involved as
early as possible in the network design process.

Design Guide – DOC. 7977C DigitalMedia NVX Series System •13
Network Multicast Functionality
NVX networks rely on multicast functionality exclusively to send and receive video, even in
the simplest case of a single encoder endpoint and single decoder endpoint. Internet Group
Management Protocol (IGMP) multicast in the Ethernet context replaces a fixed switching
architecture in AV distribution. The challenge is to ensure that such traffic is capable of any
permutation of one encoder to many decoders, and vice-versa without adversely affecting
or being affected by other network devices.
Segregation of NVX traffic by using a VLAN or MPLS is generally the first step in enabling
multicast. A VLAN or MPLS ensures that NVX traffic stays on the NVX network and does not
route out to other network segments to interfere with their operation, nor allow traffic from
other network segments to interfere with NVX operation. Within that segment, however, all
ports can still be flooded by IGMP traffic regardless of if that traffic was intended to be sent
or received by a network device at any given point in time. This will result in interference with
the network operation and can even be a means of implementing a denial-of-service attack
on a network if done maliciously.
To ensure that only traffic between intended multicast senders and multicast receivers
appears at a given port, a switch feature called IGMP snooping must be enabled. Snooping
refers to the ability of the switch to limit multicast traffic only to ports between intended
senders and receivers. The NVX supports both versions of IGMP snooping, IGMPv2 and
IGMPv3.
In order for the switch to understand where route limiting will be specifically implemented in
the network for multicast traffic, a network switch that assesses and maps the network for
multicast nodes in the NVX network called an IGMP querier must be enabled. Normally, a
single switch is selected by address to act as the IGMP querier, but the switch with the
lowest numerical IP address on the network will typically be the default when multiple
switches are configured as queriers. The default leave time for the querier (typically around
125s) is normally sufficient for an NVX network unless there are other specific requirements
that a network designer must account for.
Further assisting the discovery and optimization of multicast network traffic routing is a
feature called Protocol Independent Multicast (PIM). There are different modes of PIM such
as Sparse Mode (PIM-SM), Dense Mode (PIM-DM) and Source-Specific (PIM-SSM), but
NVX networks should be configured to use PIM-SM. PIM-SM assists in finding the shortest
trees per path from any given multicast source to multicast receivers on a network and is
more scalable than PIM-DM or PIM-SSM. PIM-SM also prevents edge-switch link saturation
as well as network loops in the routing of multicast traffic.
Enabling network QoS is also useful in prioritizing NVX traffic over other ancillary traffic such
as control traffic. Although there are multiple mechanisms that enable QoS, the most
essential part of this is to enable the highest priority possible on IGMP multicast traffic. For
example, enabling 802.1q VLAN tagging support in the switch, and then enabling and
assigning an 802.1p priority (for example, 5, 6, or 7) to NVX addresses, ports or IGMP
protocol traffic, will prioritize NVX traffic over other traffic at both the source and destination.
Other traffic such as HTTP for web services, or SSH for console access, would be assigned
lower priority numbers (for example, 0 to 4) based on their respective addresses, ports, or
protocols. Other protocols exist for QoS (depending on the switch vendor) but are
configured in a similar way to the 802.1p and 802.1q example. It is critical to ensure that all
traffic types are affirmatively accounted for in QoS setup to ensure successful QoS
operation.

14 •DigitalMedia NVX Series System Design Guide – DOC. 7977C
Network Security
Security is an important consideration in all networks, including those built for NVX. Some of
the security concerns network designers should be aware of includes the following:
•Unauthorized individuals attempting to eavesdrop on video, audio, or network traffic
•Individuals without proper authorization attempting to change specific settings,
such as stream bandwidth, within endpoints and placing additional devices on the
network
•Individuals attempting to commit acts of sabotage, such as bringing down a video
network
From a design perspective, security requires the support of particular capabilities within all
devices on the network. NVX employs the following security features:
•802.1x is used to ensure that devices on the network have been explicitly
sanctioned by the network administration team, which protects against
unauthorized devices being added to the network and gaining access to sensitive
content.
•Active Directory services for endpoint administration can be used to ensure that
administrative privileges for NVX devices could be centrally managed, granted, and
revoked when necessary.
•NVX endpoints use the industry-standard AES block cipher with robust PKI for
stream encryption to protect content from unauthorized access as it traverses the
network.
•SSL-based Secure Cresnet-over-IP (CIP) for NVX control ensures that control
processors and NVX devices communicate with the intended party device and that
commands and status cannot be monitored by any unauthorized device on the
network.
•SSH-based command-line console access for device configuration and status
protects the device console from access by unauthorized users.
Crestron’s link encryption, Secure Crestron-over-IP, and SSH command line console
access are both inherently available and automatically configured within devices and
support software. The designer should therefore focus on 802.1x and Active Directory
services within the design.
For additional information on deploying security with Crestron products, refer to the
DM-NVX Series Supplemental Guide (Doc. 7839), the IP Considerations Guidelines for the
IT Professional Design Guide (Doc. 4579), and the Crestron Secure Deployment Guide
Online Help (OLH 5571).
Network Design Considerations
With the understanding of the main network implications of the NVX design, carefully
consider and apply the following network design best practices:
•Use nonblocking Layer 3 switches with port-based QoS, such as 802.1p with
802.1q at all stages of the design. Employ sufficient switch bandwidth and port
speeds, as less expensive switches cause loss of capability in the network.
•Choose switches with sufficient bandwidth at each segment, from edge to core, to
accommodate a nonblocking architecture for NVX endpoints and any additional
needs.

Design Guide – DOC. 7977C DigitalMedia NVX Series System •15
•Choose an appropriate network topology. Consider all requirements for the
network, including basic functionality and redundancy, and whether video walls or
repetitive display signage are necessary. When planning on a topology for the
network, ensure that existing network IT staff and experienced network architects
are involved in these decisions.
•Enable an IGMP querier on at least one switch in the NVX network. The IGMP
querier ensures that all switches know which multicast transmitters and receivers
are connected to which switches in the network. Enabling IGMP querier on multiple
switches causes the switch with the lowest value of IP source address to take
precedence and act as the querier.
•Consult the network switch manufacturer’s documentation to ensure the uplinks
are properly configured to support multicast traffic.
•Use switches that support 802.1x for endpoint authentication by implementing
802.1x endpoint authentication through TLS or MS-CHAP v2. Only authorized
endpoints can communicate with the network, preventing any potential denial of
service or unauthorized traffic snooping and network analysis for weaknesses.
•Ensure VLANs or MPLS are implemented correctly. Leveraging existing switch
infrastructure with VLANs or MPLS can cause conflicts with existing and future
network provisioning needs. It also requires substantial network implementation and
management experience to operate over the long term. If a dedicated network for
NVX is not going to be used, VLANs must be implemented correctly with their own
IP subnet, and MPLS networks must be configured correctly.
•Account for even-numbered NVX primary stream multicast address assignments
since both primary and secondary multicast streams are possible. The assignment
of multicast IP addresses for primary streams should be even numbered to allow
the secondary stream to be assigned to the odd numbered IP address one higher
than the primary stream’s IP address. For multicast IP address assignment, refer to
the guidelines in IETF RFC 3171.
•Use Active Directory for administration security. The use of Active Directory with
NVX endpoint logins allows for easy, seamless, and better-controlled access from a
central directory authority with fewer risks.
•Use a DHCP server with link-layer filtering. NVX has the option to configure IP
addresses of endpoints with both fixed IP addresses and by DHCP. However, using
a DHCP server with short lease times, MAC address filtering, and sufficient address
space for future needs makes network management easier.
•Enable IGMPv2 (NVX default) or IGMPv3 multicast snooping on all switches in the
NVX network. This is a requirement for all designs to enable multicast delivery to
multiple endpoints. Switches without IGMP snooping enabled that receive a
multicast stream will transmit that stream to all ports simultaneously, immediately
saturating all network links.
•Use RSTP on the network to ensure that network loops are discoverable and
prevent deployment issues. Network management should account for RSTP
discovery downtime upon network changes.
•Use and plan for XIO Director for endpoint management. XIO Director requires an
additional network appliance whose inclusion in a design will require additional
consideration to enable management of the entire NVX network from the XIO
Director server.

16 •DigitalMedia NVX Series System Design Guide – DOC. 7977C
•Use daisy chaining to connect video wall endpoints or repeated displays. In the
case of video walls or endpoints that receive the same source from a single
transmitter to feed multiple identical displays or in a video wall using a single
source, it is simpler and less expensive to daisy chain the network from device to
device.
•Route and configure nondedicated DHCP, RADIUS, Active Directory, or other
servers with NVX outside of the NVX network to have access to the NVX network
appropriately to provide these services.
•Disable IGMP proxy on Crestron control processors with routers. Crestron control
processors with routers, such as the CP3N, Pro3, AV3, and the DMPS3 line,
should have IGMP proxy functionality disabled when connected to the NVX network
to ensure NVX multicast traffic does not interfere with the control processor.
•Account for high-bandwidth external USB as an endpoint for bandwidth. If
high-bandwidth USB devices are to be used, ensure that the bandwidth is
accounted for as an entirely separate 1 Gbps link since USB 2.0 bandwidth can
consume 480 Mbps of the 1 Gbps link.
•Leverage professionals with experience in high-performance network design, since
most Pro AV designers are not typically expert network designers (and vice-versa).
This can be of critical importance to the success of the network design from a both
cost and schedule perspective.
•Ensure that multicast IP addresses do not share the multicast MAC addresses.
Sharing of MAC addresses can cause network collisions and prevent the normal
operation of the NVX network.
NVX System Installation
With a well-thought-out design of the NVX system in hand, the installer bridges the design
and specification with real-world implementation. The challenges involved in NVX installation
can be substantial yet manageable with sufficient forethought of some of the most common
hazards that can prevent an optimal end user experience. As with the design phase, the
installation phase should ensure that the interaction between designer, installer,
programmer, and end user is considered in all installation decisions.
NVX Endpoint Installation
Each NVX endpoint will have unique installation requirements that depend on the following:
•If the network connectivity of the endpoint will be copper or fiber
•If the endpoint is card-based or stand-alone
•If the endpoint should be configured to encode or decode a stream, or will be
switched dynamically between modes
•If there are additional local HDMI inputs to configure
•If source autoswitching or external switching control will be used
•If there are additional audio sources that require encoding
•If a USB device or host functionality is required
•If the endpoint is part of a video wall or goes to multiple identical displays