Random lag on connection

when i try to connect to my friend's server, the connection seems randomly laggy, sometimes it's 50ms, 40ms, 60ms, but sometimes it tooks 1, 3 or 7 seconds time curl -vv 'http://ipaddress/foo.json ' * Hostname was NOT found in DNS cache * Trying ipaddress... --> SLOW AT THIS LINE !!! * Connected to ipaddress (ipaddress) port 80 (#0) > GET /foo.json HTTP/1.1 > User-Agent: curl/7.37.0 > Host: ipaddress > Accept: */* > < HTTP/1.1 200 OK < Date: Tue, 24 Jun 2014 02:51:45 GMT * Server Apache/2.2.27 (Unix) mod_ssl/2.2.27 OpenSSL/1.0.1e-fips mod_bwlimited/1.4 is not blacklisted < Server: Apache/2.2.27 (Unix) mod_ssl/2.2.27 OpenSSL/1.0.1e-fips mod_bwlimited/1.4 < Last-Modified: Tue, 24 Jun 2014 02:42:12 GMT < ETag: "2e8109e-871-4fc8be82affe4" < Accept-Ranges: bytes < Content-Length: 2161 < Content-Type: application/json How could I know which part of the system that causes this? I've tried to disable mod_bwlimited, but the lag still happened I've tried to use another web server (monkey) on another port, it still happened the server: Linux bar 2.6.32-042stab090.3 #1 SMP Fri Jun 6 09:35:21 MSK 2014 x86_64 x86_64 x86_64 GNU/Linux Also when I tried to change /etc/sysctl.conf and using sysctl -p using root: net.ipv4.tcp_tw_recycle = 1 net.ipv4.tcp_tw_reuse = 1 fs.file-max = 524288 It shows: error: permission denied on key 'net.ipv4.tcp_tw_recycle' error: permission denied on key 'net.ipv4.tcp_tw_reuse' error: permission denied on key 'fs.file-max' Maybe that values was restricted by the hosting company?