A terminal site host doesn’t connect to protection ground, having a meeting in about 20-30 minutes then will be offline.
Repeat detected LIU port and did not find problem. Arrived to the site, after detection found the terminal power didn’t connect to protection ground. Terminal background test line bit error in 67 to 90%, after the installation of protection ground (zero AC power <1V) and replace MUX board terminal system is working properly, and join the conference also return to normal.
When didn’t connect to protection ground, leading to the terminal host and the transmission equipment is not common ground, so the transmission has high bit error rate ,and will appear offline phenomenon.