A common problem which we get plenty of support calls for but is very rarely ever a problem to do with the VMS software or hardware – is jerky (not smooth) video! Mirasys spends huge amounts of time testing and re-testing to ensure that video can be displayed to the user as smoothly as possible. However, video display relies on a number of factors to be correctly configured – if any of these are incorrect you will face viewing problems.
Let’s start by looking at the network.
There are a number of factors relating to the network that can cause jerky video:
- Are all connections relating to recorders and viewing stations plugged into a 1 Gigabit port or higher? For a small system it is fine to plug a single camera into a 100 Mb port. However if there are several cameras in your system, we recommend using a Gigabit connection so not to overload the network or your video will be jerky. Not all connections are gigabit by default, you should check this.
- Remember a network port is being used inbound and outbound. If you are recording 500 Mbits/s of data and you want to view it – that will never work in a single Gigabit Ethernet connection. Even 250 Mbits/s in both directions will result in problems on the Gigabit best network adapter.
- Have you configured all you network setting correctly – a simple typo can result in weird behaviour if not a complete loss of video. Check the Subnet Masks match and that your Gateway and DNS are correctly configured. In theory you only need a Gateway if you are bridging 2 networks but (and we don’t know why this is) some cameras seem not to work if they do not have a Gateway address – so what do you use? If you don’t have a real Gateway often using the recorder as a Gateway address can work. In other cases a poorly configured Gateway can cause even more problems.
- Check the physical connections – sometimes something as simple as a faulty cable can cause video skipping. Always use high-quality cabling and ensure that your cabling meets the requirements of your equipment. Pick a wiring standard (568-A or 568-B). Also check the RJ45 termination: poor termination can result in POE or transmission problems. A good cable tester can also save you hours of valuable time.