Hello, I haven't measured that, but maybe this is helpful: I have measured some time ago was the latency in a hidden service (rendezvous) circuit: Client - guard - middle - rendezvous -- middle - middle - guard - HS [6 hops] I did the test by installing an OpenVPN TCP server on the hidden service that listened on 127.0.0.1 and allocated VPN IP's in subnet 10.8.0.0/24. The client connected via Tor's socks5 to the .onion address where the VPN server was listening and I was able to do ICMP and UDP between vpn client (IP: 10.8.0.5) and vpn server (IP: 10.8.0.1). On average the latency was about 600-700 ms. The result is heavily dependent on all the relays in the path, so I am not sure how can we test this to an exact value. You can try now and get lucky with only fast relays in the path and have a 400 ms latency and you can try later and be less lucky and have a 800 ms latency. On 3/10/2016 4:42 PM, Zack Weinberg wrote:

Before I go reinventing wheels, has anyone got code to measure network latency (either RTT or one-way packet travel time will do) from a chosen Tor exit to an arbitrary destination? Latency from client to exit would also be useful.

Thanks, zw