WebDAV (Web-based Distributed Authoring and Versioning) is a standard for making files available on the internet. With this tool, users can access their data in the same way as from an online hard drive. Well known examples are Apple's virtual internet hard drive iDisk, the GMX Media Center or Telekom Austria's aon-Online Hard Drive.
Technically, WebDAV can be seen as an extension of the protocol HTTP/1.1, which offsets certain limitations of HTTP. Up until now, it was usually only possible to upload single files from online documents (HTTP-POST). With WebDAV, whole directories can be transferred. In addition, a version control is specified.
Advantages
Through the enormous spread of the World Wide Web, Port 80 (used by HTTP) belongs to the ports which generally do not get blocked by firewalls. While multiple additional ports of a firewall have to be opened with other transmission methods such as File Transfer Protocol (FTP) or SSH (in conjunction with scp or SFTP), this is not necessary with WebDAV, because it builds on HTTP and therefore only requires Port 80. The opening of additional ports of a firewall increases the expenditure of time and effort for system administrators, and entails additional risks, for instance random TCP ports can be tunnelled through a firewall with SSH connections.
