Network Basics

Network Layout

1. Network Connections (Wired vs. Wi-Fi): Graphics PCs and Video mixer PCs must be connected using physical Ethernet cables. Wi-Fi is not recommended for production NDI video because bandwidth fluctuations, interference, and latency jitter can cause dropped frames or an unstable video feed. Devices that only transmit competition data, such as Scoreboard PCs, may use Wi-Fi if the connection has been tested and proven stable. A wired connection is still preferred whenever available. 
   
2. Subnet: Every production computer should operate on the same IP subnet (e.g., 172.20.1.X). 
   
3. Routing: A router connects the network to the internet and hands out IP addresses automatically. Do not place an extra router between your production computers. Avoid multiple switches between the Graphics PC and the Video mixer PC.
   

Switches and Cables

1. Gigabit Network: You should use a Gigabit switch to handle both the data packets and the video data simultaneously without dropping information. A 1 Gbps connection is the minimum for NDI workflows. Multi-mat systems must be tested under full load because several high-bandwidth NDI streams can approach the practical capacity of a Gigabit link. Use 2.5 GbE or 10 GbE where testing shows that a Gigabit connection does not provide sufficient headroom. 
   
2. Cables: Use high-quality Cat6 Ethernet cables suitable for the event environment. In areas with significant electrical interference, shielded Cat6 cables are recommended. A single Ethernet cable segment must not exceed 100 meters. For longer distances, use an additional network switch or a fiber-optic connection.  
   
3. Managed Switch Settings (If applicable): Managed switch settings should be verified before the event and adjusted to the specific network configuration:
   
1. Storm Control: Disable Storm Control if testing confirms that it is blocking the required UDP or NDI traffic. If it remains enabled, ensure its thresholds are high enough for the production workload.
   
2. Green Ethernet: Disable Energy-Efficient Ethernet or similar power-saving functions on production ports if they cause connection interruptions or latency.
   
3. RSTP: Enable Rapid Spanning Tree Protocol when the network contains redundant connections or there is a risk of creating a network loop.
   
4. VLAN: Keep all production devices on the same VLAN unless routing between VLANs has been explicitly configured and tested.
   

Internet Access and Firewall Ports

1. Required Network Ports & Traffic
   Your firewall must be configured to allow specific internal traffic for the system to function across the Local Area Network (LAN):
1. TCP port 855 – inbound on the JudoNet PC: Receives WebSocket data from the Scoreboard PCs.
   
2. UDP port 5000 – inbound on the Graphics PC: Receives JudoNet broadcast data in CGplay.
   
3. TCP port 5250: Carries commands from CGplay to CasparCG. If both applications run on the same computer, the connection is internal. If they run on separate computers, inbound TCP port 5250 must be allowed through the Windows Firewall on the CasparCG PC.
4. NDI traffic: Allow the installed NDI applications and discovery traffic through Windows Defender Firewall on the Private network profile.
   
5. ICMP (Ping): Allow ping traffic for network diagnostics
   
2. Internet vs. LAN
   The essential CG data flow runs over the local LAN. Live contest data can continue to travel from the Scoreboard applications through JudoNet to CGplay and CasparCG even if the internet connection is interrupted. However, internet access is still required by some connected applications:
   
1. JudoManager Server and JudoNet PC: Require internet access for their normal online services and synchronization.
   
2. Video mixer PC: Requires internet access when streaming to an online platform.
   
3. Graphics PC: Requires internet access for IJF events to retrieve data from the JudoBase Cloud API, including competitor statistics and predictions. For national events, the essential CG workflow can operate over the LAN without internet access.
   
4. Scoreboard PCs: Do not require internet access for the CG data path, provided they can reach JudoNet over the LAN.
   

Security and Windows Settings

1. Avoid Mixed Connections: Do not use Wi-Fi and wired Ethernet simultaneously unless the network interfaces and routing priorities have been deliberately configured. For a standard event setup, enable only the network adapter used for the production network. This prevents Windows from routing competition data through the wrong interface.  
   
2. Windows Profile: Set the Windows network connection to the "Private" profile on all computers. If left on "Public," incoming UDP data may be blocked. 

1. System Security: Turn off VPNs, third-party firewalls, and network "optimizer" programs because they frequently block the UDP data. Tell your Antivirus software to ignore the "CG" folders so it does not slow them down or block them during a live match. 
   
2. Power & Updates: Set the Windows power plan to "High Performance" and disable all power-saving features on your Network Card via Device Manager. Pause Windows updates to stop the computer from unexpectedly restarting during a live competition.  
   

Mat Setup Architectures

1. Single PC Setup (Example): For pre-event testing or very small competitions, a single highly capable computer can run CGplay, CasparCG, and OBS/vMix simultaneously.
   

1. Multi-Mat Setup (Example): For larger competitions, software workloads must be separated across multiple dedicated machines to prevent video encoding bottlenecks. The number of mats a single Graphics PC can render depends on its hardware capacity. If your tournament exceeds those limits, simply divide the workload. For example, assign Mats 1-5 to Graphics PC 1 and Mats 6-10 to Graphics PC 2. Depending on your production workflow, these Graphics PCs can then send the graphics to software Video mixer PCs via NDI through your Gigabit LAN Switch, or send them directly to a professional Hardware Video Mixer via physical SDI cables.

Setup and Testing

FAQ

1. Does the system need the internet to work? The essential scoring and graphics traffic runs over the local LAN, so the CG data path itself does not depend on the internet. However, JudoManager Server and JudoNet require internet access for their normal operation, the Video mixer PC requires it for online streaming, and the Graphics PC requires it at IJF events for JudoBase Cloud API features.
2. What is the easiest way to block the internet on a Scoreboard PC? You can block their internet by leaving the Default Gateway and DNS settings blank if you use static IPs. If you use Dynamic IPs, you can use the built-in Windows Defender Firewall to create an outbound rule that blocks web traffic on Ports 80 and 443.
   

If you have access to your main router, you can also restrict access by blocking the specific hardware addresses (MAC addresses) of your scoreboard computers.

1. Can I use Wi-Fi to connect the Graphics PC? No, it is not recommended. Wi-Fi introduces risks of packet loss, radio interference, and latency jitter which will drop your video frames. You must use a wired Ethernet connection for any PC handling NDI video. However, devices that only transmit data packets (like the Scoreboard PCs on the mats) can use Wi-Fi.
   
2. Can I put JudoNet PC and the Graphics PC on different subnets? This is not recommended. Keep JudoNet PC and the Graphics PC on the same local network, because UDP data cannot easily travel through routers.
   
3. Why do I need to disable Windows Updates and set my network to Private? Pausing Windows updates stops the computer from unexpectedly restarting during a live competition. Setting your network profile to "Private" tells the Windows Firewall that you trust the local system. If left on "Public," incoming UDP data may be blocked.