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Designing an Optimized Industrial Network for HD IP Surveillance

Present trends in the video surveillance industry indicate an increasing number of analog CCTV systems migrating to HD IP surveillance networks. Analysts (IMS Research) also report that by 2015, more than 70% of all network cameras shipped will be capable of delivering megapixel resolutions. In recognition of this shift in the security industry, the U.S. Department of Homeland Security (USDHS) recently released a handbook documenting the guidelines for best practices in design, selection, and deployment of video surveillance systems (VSS), as well as identifying the minimum requirements for infrastructure devices and components. The USDHS also recommended that HD surveillance be used whenever possible, stating that the HD format offers high color fidelity and is the only megapixel subset with resolution and frame rate standardization.

As video surveillance applications expand in size and require higher resolutions, it becomes imperative that video traffic management and network resource allocations are at optimal levels to avoid network congestion. Network scalability for future expansion requirements is also an important factor to consider when planning HD IP surveillance deployment.

Identifying the type of video surveillance that is required can help to determine the amount of bandwidth and storage that will be needed for the surveillance network. The USDHS also cites three service classifications of video applications; real-time observation (live monitoring), forensic review (event recording), and recognition (intelligent video analysis). Each of these classifications will have different network resource demands that will directly impact bandwidth and storage requirements. It is possible for a video surveillance system to require more than one service classification type, which will require additional network resources.

Bandwidth and Storage Calculation

Whether upgrading an existing network or installing a new infrastructure for IP surveillance, key information regarding the needs of the video surveillance system – such as the number of cameras, video resolution, FPS rate, scene complexity, and compression type – must first be gathered before bandwidth and storage requirements can be determined.

Bandwidth – There are many tools available to calculate bandwidth requirements for IP surveillance. However these numbers are purely estimates and should only be used for reference. Bandwidth requirements can be greatly reduced with distributed storage and intelligent video analytics (IVA). While a 100-Megabit network will generally be enough for a network of 10 to 15 cameras (each using roughly 3 Mbps of bandwidth), a surveillance network with more than 15 cameras will likely require a Gigabit backbone for video transmission.

Storage – Storage requirements can vary greatly depending on factors such as resolution, number of cameras, frame rate, compressions type, and days of storage. A distributed recording platform to store video files locally is generally recommended to reduce network traffic, especially for upgrading an existing network that may not necessarily have the bandwidth required to store video files on a central server.

Moxa offers a convenient tool for estimating bandwidth and storage requirements for video surveillance networks: http://www.moxa.com/event/Net/2012/IP_CCTV_Calculator/index.htm#table2

Reducing Network Bandwidth Consumption and Storage Requirements

Distributed Recording and IVA – Storing video footage on local SD cards or network-attached storage devices (NAS), known as distributed recording, can drastically reduce bandwidth consumption across the video surveillance network. Intelligent video analytics (IVA) allow software to notify security personnel and trigger event-based video streaming and recording to reduce storage requirements. For surveillance applications that do not require continuous visual monitoring, distributed recording and IVA allows security operators to access video footage for review after an event has occurred, consuming network bandwidth only when necessary.

Video Compression – Using an efficient compression format can significantly reduce bandwidth and storage requirements. The most efficient compression standard in use today is H.264, which uses an advanced intra prediction scheme to achieve average bit rate reductions of up to 50% (compared to MJPEG) and 80% (compared to MPEG-4).

Multicast – IP Multicasting protocols allow a camera to stream only one copy of every datagram to the specified address for a multicast group, where copies of every datagram are forwarded to each subscribed member of that multicast group. IGMP snooping are used by layer 2 switches to prevent network flooding from multicast traffic by monitoring IGMP messages. Multicast and IGMP snooping can dramatically reduce bandwidth requirements; their benefits include:

  • Minimized load on the source (for example, the camera) since it will only need to produce one copy of the video data.
  • Efficient use of network bandwidth and scales well as the number of multicast group members increases.

High Performance Industrial Network to Ensure Uninterrupted IP Surveillance

Availability - Network availability directly affects the bottom line, and needs to be a primary requirement in any network design. For non-stop operation and minimize system downtime, we recommend using millisecond-level network redundancy for both wired and wireless Ethernet devices.

Infrastructure - A layered edge-to-core architecture (edge, distribution, and core) will enhance network flexibility, scalability, and manageability, which allow operators to easily plan for storage, bandwidth, and redundancy requirements to quickly deploy future surveillance network expansions.

Security - Cyber security is a requirement for any network infrastructure. In addition to using secure routers to provide firewall/VPN to deny unauthorized access, 802.1x or port-based authentication can be applied to IP surveillance applications with high security requirements.

Efficiency - To increase network efficiency, the following network features are recommended:

VLAN - VLANs provide a network segmentation system that is far more flexible than traditional networks. VLANs can provide the following benefits:

  • VLANs ease the relocation of devices on networks: Hosts on a VLAN do not need to be on the same physical network and can even be located in different remote locations. VLANs allow network administrators to logically group network nodes based on functionality and/or service type.
  • VLANs help control traffic: With traditional networks, congestion can be caused by broadcast traffic that is directed to all network devices, regardless of whether or not they need it. VLANs increase the efficiency of your network because each VLAN can be set up to contain only those devices that need to communicate with each other.

QoS - QoS allows data prioritization so that time-sensitive and system-critical data can be transferred smoothly and with minimal delay over a network. The benefits of using QoS are:

  • QoS assigns priorities to different categories of traffic. For example, set higher priorities for time-critical or business-critical applications.
  • QoS provides predictable throughput for multimedia applications, such as voice over IP, and minimize traffic delay and jitter.

Recommendations for IP Surveillance Networks

The USDHS video handbook contains recommendations, requirements, and best practices for digital video surveillance systems (VSS). Moxa’s comprehensive line of IP surveillance network solutions includes products that meet or exceed the following USDHS recommendations for design, selection, and deployment of digital VSS.

Video surveillance network recommendations
High recoverability for power and network connections (redundancy)
IEEE 802.3af/at compliance for PoE applications
Cyber security (802.1x port-based authentication)
Wide operating temperature range
QoS for packet/port prioritization
VLAN for isolation and added security
Additional considerations for edge devices (cameras and NVRs)
ONVIF for interoperability
IP66 for ingress protection
SDK for IVA embedded applications
H.264 and MPEG-4 compression
Imager viewing options for day/night, color, and black/white
Wide focal length range for maximum magnification (zoom)
HDTV conformance
Internal memory recording (SD storage)

Moxa’s Industrial Ethernet Solutions for HD IP Surveillance

To optimize network efficiency, Moxa's industrial Ethernet solutions can be deployed using either a centralized or decentralized network platform to achieve maximum performance and flexibility.

High-bandwidth Industrial Ethernet Portfolio

To meet dynamic HD video streaming requirements, Moxa's edge-to-core solutions enable fast, flexible, and strategic deployments of industrial Ethernet infrastructures to accommodate a wide range of video surveillance and security applications.


Next Generation of HD IP Surveillance

Moxa's IP surveillance solutions deliver HD (720p/1080p) image quality with low latency and bandwidth optimization for industrial video surveillance applications in extreme outdoor environments. Designed for a wide range of harsh weather conditions, Moxa's new generation of extreme-weather IP cameras can perform reliably from -40 to 75°C without the need for a fan or heater, and offer many advanced options, such IR illuminator, WDR (wide dynamic range), and De-mist, to enhance image quality for applications in areas with low visibility.


Professional Industrial Networking Service (PiNS)

Now network designers can harness Moxa’s industry-leading expertise through Moxa’s professional industrial networking services (PiNS). Moxa knows how to tailor network products for the specific needs of each network by using the standards, protocols, and resilient technology built into Moxa’s products and solutions. PiNS covers every stage of network deployment, from network design and planning, to optimization and configuration review, all the way to technical support service and product training. Along the way, PiNS customers receive specific knowledge transfer from Moxa and product training tailored for network managers, operation staff and maintenance engineers.

Migration from isolated analog CCTV systems to IP-based HD surveillance does not require a complete video network overhaul. In fact, an IP upgrade can be done in multiple stages to accommodate various budgets as operators wait for the existing analog components to end their life cycles. The combined benefits of remote manageability, superior image quality, network scalability, intelligent functionality, and seamless interoperability with other security systems, give IP video surveillance many advantages over traditional isolated analog systems.

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