Configuring a PC for Satellite Communications
Question: We created a product to send webcam pictures automatically over the Globalstar system. These are small files, 30k-50kbytes, and can be transferred quickly, in about a minute. This is used in a number of places — for example, in marinas to show the status of the weather and the vessels, at vacation cabins to show the local weather and also to record unexpected foot traffic near the cabin, and in forests to detect smoke. We post these on websites and we also send critical photos to relevant people and/or response agencies. We’ve been transferring data over the satellite connection for many weeks, with great success. All of a sudden, it seems to be taking a LOT longer to transfer the same basic quantity of email and data. Why?
- By default, whenever an internet connection is established on a PC, you have to deal with the fact that, by default, the internet connection is available to ALL applications on the PC.
- This can be modified with special routing rules, but that is by no means standard.
- If there are other applications on the PC that want to do application updates or do other things on the internet (message transfer, location updates, queries, unrelated backkups), these other applications will use the internet connection as soon as it is up. This extra traffic will compete with the transfer of your pictures and make the picture transfer take longer. So, for optimum performance of your product, it is essential to make sure that your webcam data transfer application is the only one that is going to be using the internet connection
- Regardless of the method that your product uses to set up connections, we recommend that you also set up a similar test PC at your main facility. This should be configured the same as your units in the field. This test setup should be always available and should be used on a regular basis, because whenever there are application updates or operating system updates for your PC, the situation can change and, all of a sudden, you can be faced with an apparent reduction in efficiency.
- Whenever you notice a change in the efficiency of data transfer, make sure that you have found all the ways in which your primary data transfer function can be effectively de-prioritized by other processes on the PC. When your satellite connection is used by these other unwanted processes, the result is longer data transfer times, increased airtime costs for the customer, and more calls to your customer care center.
- As you develop tools to monitor bandwidth usage, you will be better able to troubleshoot problems that a customer may report.