I can confirm that profitserver.ru at Chelyabinsk location has TSPU (government) DPI system, at least on one of their links for some of the destination IPs. On that link the filtering is the same as a residential connection from ER-Telecom.
The TSPU could be detected by 307 HTTP reply with Location header and nothing more:
# curl -v rutracker.org * Trying 45.132.105.85:80... * TCP_NODELAY set * Connected to rutracker.org (45.132.105.85) port 80 (#0)
GET / HTTP/1.1 Host: rutracker.org User-Agent: curl/7.68.0 Accept: */*
* Mark bundle as not supporting multiuse < HTTP/1.1 307 Temporary Redirect < Location: http://lawfilter.ertelecom.ru/ * no chunk, no close, no size. Assume close to signal end
Contrary to torproject.org request, which doesn't seem to be routed via TSPU (but via another DPI box, at Megafon):
# curl -v torproject.org * Trying 95.216.163.36:80... * TCP_NODELAY set * Connected to torproject.org (95.216.163.36) port 80 (#0)
GET / HTTP/1.1 Host: torproject.org User-Agent: curl/7.68.0 Accept: */*
* Mark bundle as not supporting multiuse < HTTP/1.1 302 Found < Location: http://m.megafonpro.ru/rkn?channel=3 * no chunk, no close, no size. Assume close to signal end
The IP addresses of blocked Tor relays and bridges are not reachable over Chelyabinsk profitserver as well.