VSAT latency emulation
pieterdevries last edited by
I'm trying to use pfSense to emulate one of our satellite connections so we can test out equipment without needing an entire installation. I've followed a lot of guides and forum posts, from here among other places, and I can achieve two things separately but not at the same time.
Using the limiters I can limit the connection to a certain bandwidth (1534 kbps down/ kbps 1024 up in our case) and this works. In the same limiter I can also increase the latency (due to speed of light about 250 ms per leg) which also works, resulting in a ping of 500. However as long as I have the increased latency set, the bandwidth no longer reaches what I set and in fact maxes out at around 800 kbps. Reducing the latency increases the throughput and setting it to 0 gets us to the full bandwidth set. I also tried just increasing the bandwidth limits, but the throughput remains at about 800.
From practical experience I know we can reach the full 1500 kbps throughput on the real VSAT link, so I'm assuming the satellite modem does something clever in the background, but I can't figure it out. Anyone able to help me how to decouple the latency from the bandwidth in the limiter?
bobbenheim last edited by
@pieterdevries I am seeing the same thing with scheduler set to FIFO and increasing queue length to 200000 doesn't make a difference. Testing WFQ, QFQ, Round Robin and PRIO as scheduler does work with default queue length of 1000. I am not sure if something is wrong in Pfsense but you could go with PRIO as scheduler for now.