Why do packets disappear when the channel is loaded?

Question

Computer networks

Hello.
During a speed test or other load, packets begin to disappear (about 5% from a hundred packets). If you connect the Internet directly to the PC, then everything is fine. Tell me what could be the problem?

Answer 1

When the link is busy, packet drops are normal behavior.
If the load does not fill the entire channel, then the router may be too weak - there is not enough processor speed to process all the traffic transmitted over the channel.