Unicast vs. Multicasting Networks in Video Surveillance

Video surveillance is all around. From traffic monitoring to retail management, this technology complements various security measures. These videos can stream via internet protocol (IP) cameras over a network in two ways — unicasting and multicasting.

Each network has its applications and purpose within an organization. Choosing between the two depends on who needs access to the videos, where they access from and how they consume the content. Finally, you must stipulate whether you are streaming over a public or managed network. Understanding the differences between these options and how you can optimize your network to support your video surveillance system will allow you to use the best option to its total capacity.

Understanding the Basics

Unicast and multicast networking in video surveillance have distinct uses. Some organizations use a hybrid of both. Understanding how these systems work can help you design, implement and manage your video surveillance networks. The choice between these two networks depends on your bandwidth requirements, system size and access control to the video streams.

If improperly configured and monitored, multicast can easily become broadcast. For example, in a large conference call where everyone is unmuted, every noise is a distraction to the network. Broadcast is a to-everyone conversation. It’s never efficient but sometimes required.

What Is Unicast Networking?

Unicast transmission directly communicates between the client’s application and the camera. Over-the-top (OTT) media is streamed via unicast networking, similar to Hulu and Netflix. In surveillance, each IP camera streams video to a dedicated destination like a network video recorder (NVR) or monitoring station. Video streams are delivered to specific devices or locations, allowing personalized access and monitoring. This sends data directly to the specified recipient without sharing it with other devices.

In IP multicasting, unicasting uses a combination of both transmission techniques. The sender transmits data to one multicast group, but network routers will use unicast communication to manage the multicast distribution tree. This setup bypasses the need for individual unicast transmissions to particular recipients. Other scenarios where this works best are:

• VoIP calls: You will get good call quality thanks to lower latency.
• File transferring: Unicast networks are reliable for sending files between two points.
• Site-to-site VPN: Unicast networks serve as a secure passage between two destinations.
• Collaborative apps: This communication supports videoconferencing, trading apps and online gaming.
• Client-server connections: Unicast networks support fast web browsing, database access and mobile apps.

What Is Multicast Networking?

The operator connects to a multicast video stream IP address with a multicast transmission. The IP camera sends one copy of the video stream to the destination. This can slow down your local area network (LAN) and disrupt other operational systems. One example is an Internet Protocol Television (IPTV) with one centralized server that can send a single video stream to various endpoints. 

This transmission is more secure than OTT content, operating in a private IP network. IP multicasting is a one-to-many model, sending data to multiple recipients at once. Additional areas where multicast networking excels include:

• IPTV: This network can live-stream media to TV boxes.
• Cloud replication: The stability of this network allows for quick and reliable data synchronizing.
• Corporate communication: Broadcasting video to all employees or live streaming events is more stable when you use a multicast network.
• Software updates: You can update software simultaneously across various devices using a multicast network without putting strain on your bandwidth.

What Is Video Surveillance?

In this scenario, video surveillance involves using cameras and recording systems to monitor activities in certain premises for management or security purposes. Additionally, these systems are used in crowd management to improve operational efficiency and monitor industrial processes. The video surveillance camera market was valued at $35 billion in 2022, showcasing how important this technology is becoming.

Components used in this surveillance often include:

• IP-based cameras
• NVR video recorders
• Monitors
• Storage devices 
• Video management software (VMS)

Be sure to plan for additional storage for your video feeds. Factors like compression and retention periods can impact the amount of storage your system needs.

Remote monitoring allows users to live stream and record video feeds from your surveillance cameras. Users access the feed remotely via internet-connected smartphones, computers or tablets. These feeds are secured with encryption, access control, network segmentation and regular software updates to prevent unauthorized access.

Unicast vs. Multicast: A Comparative Analysis

Unicasting needs less network configuration. It is also effective for point-to-point communication but is more bandwidth-intensive, which can put a lot of strain on your network infrastructure. The most significant benefit unicast networking offers is that the endpoints can receive video based on the bandwidth available and the service device. In large-scale operations, unicasting may become more complex and resource-intensive to manage. It also runs the risk of contributing to network congestion when you need to transmit numerous video streams.

Multicast networks need multicast routers to support multicast transmission. The primary benefit of this option is its ability to lower network traffic and boost bandwidth. This setup allows multiple users to access one live video stream with little to no lagging. It does not quickly scale to heterogeneous networks, so having an in-house managed network is best if you want to use multicasting. It is important to note that not all network devices are compatible with multicast protocols. It also does not offer encryption or security features, so you will have to take additional measures to secure these transmissions.

Choosing Between Unicast and Multicast Networking 

You’ll need to consider various factors when choosing between these two networking options for your surveillance system. In addition to the advantages of each video network, evaluate your system’s needs to select the right option.

Advantages of Unicast in Video Surveillance

Unicast networks are best for private access control, where access is restricted and communication encrypted between cameras and monitoring systems. This system is also well-suited to real-time response scenarios. Unicast networking excels for video feeds serving in rapid response in security or emergency response situations. Its single-source transmission structure delivers a dedicated stream to each device or destination. The advantages of unicast networking include:

• Individualized access: You can access each camera’s feed independently, helping with personalized monitoring and recording.
• Better quality and control: With dedicated bandwidth allocation and individual stream control, unicast produces higher-quality video streaming.
• Easy implementation: Unicast systems are simple to manage and configure. This simplicity makes them a good choice for small-scale surveillance systems.

Advantages of Multicast in Video Surveillance

Broadcasting video streams over wide area networks (WANs) or LANs to various sites will benefit from multicast networks. Some examples of these scenarios include live events, video conferences and public safety monitoring. One of the most significant advantages of multicast networking is its efficient bandwidth use. Three additional benefits to consider are:

• Reliability: Through multicasting, video streams consistently to multiple devices without lagging.
• Scalability: This system works well for larger surveillance systems where multiple devices access the same video feed. 
• Lower network congestion: Network congestion is minimal as a single stream sends to multiple devices to reduce duplicated traffic.

Evaluating Your System’s Needs

Successful multicast deployment and operations require a complete life cycle approach. There is no “flip the switch” scenario. It is essential to evaluate your current network design and fiber layouts because video surveillance networks are not the same as audio-visual networks or IPTV designs. You need to assess your current system, as well as its capabilities and potential for growth in the future. Look into the following factors:

• Bandwidth requirements: Note your network’s bandwidth limitations and consider whether unicast or multicasting will best align with this capacity. Bandwidth is measured in bits per second (bps) or bytes per second (Bps). This refers to both the speed of downloading data and the amount of information your network can submit.
• System size: Unicast is the better choice for small-scale operations, while multicasting works well with bigger, more distributed setups.
• Network infrastructure: Consider if your current system is robust enough to handle traffic from one-to-one or one-to-many models.
• Access patterns: How many devices need to access video feeds simultaneously? If you need to give multiple devices access to the same feeds, multicasting is the right choice.
• System configuration: Evaluate your capacity to implement and manage both systems. If you need a simple setup, unicasting is the better option.

Optimizing Network Load 

Several factors impact the quality of video over unicast or multicast surveillance. Setting up a robust infrastructure with routers, cables and switches supports seamless data transfer between cameras and monitoring stations. Consistent switch configuration in the path and verification are key to success in ensuring the multicast traffic flows exactly where desired. Additional optimization measures include: 

• Bandwidth management: For high-quality video streaming, you need substantial bandwidth. Bandwidth management tools can prioritize your video streams to ensure more essential feeds are allocated. 
• Video compression: Codecs using data compression techniques like H.264 or H.265 will minimize bandwidth usage and maintain video quality.
• Network security: A decent security system will protect your surveillance system against cyber threats and unauthorized access. The accompanying software updates, firewalls and encryption can help boost network load.
• Storage solutions: Ensure you have adequate storage to retain video footage. For example, network-attached storage (NAS) is a scalable storage option that takes pressure off your network load.
• Resolution and frame rate control: Lowering these camera settings, especially where you do not need high resolution, can reduce network load significantly.
• Network infrastructure: Monitor and regularly assess the efficiency of your network infrastructure. Upgrade cables, switches and routers to accommodate higher bandwidth as your video surveillance system demands increase.
• Network segmentation: Prevent network congestion by segmenting the network and isolating your surveillance traffic from other data streams. This will inhibit surveillance data from interfering with other network operations.

Network Design That Plans Ahead

You must set up a network design that supports your unicast or multicast network without interruptions. Surveillance videos rely on bandwidth calculations and power over Ethernet (PoE) connection, which adds to network reliability. Plan ahead by incorporating scalability into your design. This will allow you to add more cameras and monitoring points without redesigning the network’s architecture. Maintain constant network performance analysis, conducting regular audits of multicast traffic flow, potential link saturation and recorder oversubscription.

Unicast network designs start with a bandwidth allocation, as this network usage is heavy. This calculation includes camera resolution, frame rate and compression settings. Adding redundant switches, routers, or network paths helps to bypass single failure points so video content can stream continuously.

Multicast protocols like Internet group management protocol (IGMP) and protocol independent multicast (PIM) connect multicast groups. This supports data routing and forwarding. You can enable multicast routing and IGMP snooping to optimize your network and support dynamic data transmission.

Integrating Into Existing Video Surveillance Systems

Whether you are integrating unicast or multicast networking into your video surveillance system, the process requires careful planning. Start by evaluating your current network system and adding the necessary tools to support it. Next, identify use cases to help you choose between unicasting and multicasting for your operations. Finally, incorporate these steps into the process:

• Device compatibility: Verify that all your cameras and monitoring stations support your transmission. Configure all devices to ensure they can handle the traffic from your surveillance system.
• Routing: If you opt for multicasting, properly route traffic across your network. This can include adjusting the quality of service (QoS) settings to prioritize video traffic.
• Test and optimize: After integrating your new system, test the transmissions to ensure they work effectively. Optimize settings where you need to.
• Maintenance and training: Provide staff training on the new configurations and establish maintenance protocols to optimize your network performance.
• Troubleshooting: Set up troubleshooting procedures to help employees resolve potential problems quickly.
• Document the journey: Keep comprehensive documentation that outlines your new configuration, best practices and the troubleshooting guidelines that support the network.

Impact on VMS

Unicast and multicast networks impact your VMS’ bandwidth, scalability, stream management and resource use. A compatible VMS can optimize either transmission to provide competent video surveillance operations.

Unicast Networking Impact

Unicast networks need dedicated resources for each video stream. This contributes to their high bandwidth demands, which increases the processing load on your network infrastructure and VMS. VMS personalizes your team’s configuration options, monitoring and recording each stream. This individual management can put a strain on your system resources, especially in scenarios where you have various cameras or monitoring stations.

Multicast Networking Impact

By reducing network load through optimal bandwidth use, multicast networks have a lower impact on VMS functionality. Stream management is more straightforward with this network, enhancing your system’s performance and scalability. This performance increase improves video streaming reliability.

Adapting Your VMS

Your VMS must be compatible with your networks to support both transmission protocols. Ensure that your VMS allocates resources efficiently to handle multicast or unicast traffic. You can head into your VMS settings to ensure video feeds are managed well and streaming without interruptions.

BCD Can Optimize Your VMS Integration

Understanding the nuances between multicast and unicast networks can help you set up a network that operates without issue. Factors like bandwidth use, scalability and access patterns will help you choose the right system for your surveillance needs. Unicasting gives you more control over individual video streams but requires more bandwidth. Multicasting reduces network load and facilitates simultaneous use over multiple devices.

The industry experts at BCD are ready to provide you with the proper surveillance hardware and software for your operations. We have installed state-of-the-art, reliable surveillance technology in over 190,000 systems spanning over 91 countries. Contact us today for a server or storage quote for your project. Alternatively, call us at 1-847-205-1922 to discuss your product or service needs.