Performance monitoring services can watch a web server 24 x 7 x 365 at an interval chosen by the site owner, ensuring that the site is always available. They can also check that the site is performing reliably and delivering content in full at a reasonable speed. The loading time of each individual page element (eg text, images etc.) can be measured, giving the total download time. This helps site owners understand of how their web site performs over time and assists webmasters in assessing and improving the quality and speed of their site.
Secure web servers using the encrypted Secure Socket Layer (SSL) protocol, which we'll discuss shortly, can also be accessed to ensure that users can use the secure data collection or payment areas of secure sites. FTP and SMTP mail servers can also be monitored, so if a web site links to an FTP server for downloading documents, or to a mail server for sending confirmation emails, then these operations can be monitored.
Companies offering this service include: