Knowledge Base Article
Article Type: Troubleshooting
Product: Symphony
Product Version:
Component: Symphony Server
Device Brands:
Created: 9-Sep-2011 4:58:05 PM
Last Updated:

Connectivity problems between camera and server when using UDP (unicast or multicast)

Probable Cause

Firewalls on servers normally are more vigilant about blocking incoming packets than outgoing packets since the user has more control over outgoing packets. However, if a TCP stream is initiated by the server (as in the case of TCP connections from server to camera), the incoming packets will be allowed.

UDP is not a connection/stream oriented protocol; therefore, the firewall does not know whether a packet from a camera is part of a conversation that was started by the server. Many firewalls will simply drop the incoming UDP packet (video) in this case.


If you are experiencing connectivity problems between camera and server, try turning off the firewall first on the server, then on any point between the server and the camera. The ports that are used to get video from a camera may not be the explicit ports specified in your camera connection string since the data and control ports may be different. The ports used can be determined by:

  1. Contacting the camera manufacturer,
  2. Looking at the configuration or logs for the camera by accessing the camera's web interface, or
  3. Using a network sniffer while the firewall is disabled.

For communication between Symphony server and camera:

  1. Enable RTSP port 554.
  2. Enable traffic:
  • to the unicast/multicast port configured on camera web page, if any
  • to/from all ports within reserved range

General Instructions

  1. When installing/configuring the server and adding cameras, disable all firewalls.
  2. After system is set up and live video from cameras works, enable the firewall.
  3. See which cameras stop working: look in the firewall logs for traffic and find which ports need to be enabled through the firewall.
  4. For the extreme case where server (AI Tracker service) allocates port dynamically, you must open full port range.


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