[PSR] Error with connection to server

Good evening, I can't connect to server 'postel.felk.cvut.cz'. And that is not just my problem, my colleagues have this problem as well. Will be the server accessed soon or where could be the problem? When I try to connect, I get this message "ssh_exchange_identification: read: Connection reset by peer. I sorry for a disruption in the evening. Best regards, Šárka Květoňová