The nerve roots pass through these joints to go from the spinal cord to the arms, legs and other parts of the body. These joints also allow the spine to bend and twist, and they keep the back from slipping too far forward or twisting without limits.
A forward ftp proxy is used to allow internal LAN clients to connect to Internet ftp servers when connecting through a PF firewall. All control and data connection rules are made by the ftp-proxy daemon and inserted into PF using anchors.
The disadvantage of a home FTP server is that you need an FTP client to connect to it, whereas web servers can be accessed using a plain old web browser. However, many modern web browsers support the FTP protocol. Instead of prefacing the URL with http://, use ftp://.