Hikvision devices are sensitive to Maximum Transmission Unit sizes. If your switch or router forces Jumbo Frames (9000 MTU) but the camera expects standard (1500 MTU), the packets fragment, corrupt, and trigger a Code 23 timeout.
Have a different error code? Search our SDK error library for codes 1 (success) through 127 (unknown host). hikvision error code hcnetsdk.dll 23
But don't let the literal definition fool you. This isn't always about slow internet. Here is your technical deep dive into why this happens and how to break through the wall. Hikvision devices are sensitive to Maximum Transmission Unit