http://stormwdumgah7rpl6fdj4yhrl2i2a7j3bkzyjcv5qxk3a6253n22thyd.onion/blog/port-striping-v2
cryptostorm blog Port striping v2 Port striping v1 When cryptostorm was first created, one of the first things we realized customers would need was the ability to connect to the VPN on non-standard ports. At the time, other VPN providers offered this by simply running extra OpenVPN instances on their servers, each listening on different ports that were usually allowed through simple firewalls (UDP 53 for DNS, TCP 80 for HTTP, TCP 443 for HTTPS, etc.).