Question: What is a mirror site?

Answer: As the number of people using the Internet continues to grow, many popular World Wide Web sites and FTP sites have become very congested. The number of visitors at these popular sites can overburden the processing power of the server computer and the capacity of the server's communication link to the Internet, causing a slow or unreliable connection. One solution to the congestion problem is create a "mirror site." A mirror site is an exact copy of the original site that can reside on a separate server, use a separate communications line and use a separate internet address or URL.

A mirror site raises many licensing issues. Even if establishing a mirror site of your own World Wide Web site, careful attention should be paid to the licenses for content on the original site. In most cases, server side software programs (operating systems, WWW server software, FTP server software, and server side helper programs) are licensed for use on a single computer, and a separate copy of the programs must be licensed for the mirror site. Further, if third party content is included on the original site, its license terms must also be analyzed to determine if placement and use of the content on a mirror site is permissible.

Some World Web Site operators and Internet Service Providers create mirror sites of popular Internet destinations in order to provide faster, more reliable access for their users. In many cases, permission is obtained, but it is often neglected in the interest of providing speed and convenience. In addition to the obvious copyright and trademark issues, establishing an unauthorized mirror site can divert viewers of the original site's content from being counted as "hits" to the original site. Since the value of a World Wide Web site is largely dependent upon the number of hits that are recorded by the server, an unauthorized mirror site can easily dilute the value of the site. Also, if an original site is frequently updated, it is likely that an mirror site will not reflect the latest version of the content on the original site. This delay can adversely affect the developer of the original site by keeping an old or outdated page in circulation after it has been removed from or changed on the original site.

It may be possible to determine if a site has been mirrored by using an Internet search engine, such a Digital Electronic Corporation's Alta Vista, to search for unique words or combinations of words in the pages on the original site. The results of the search may yield URLs other than the original site that lead to the mirrored page.

Both the law and technology are seeking ways to deal with the ease of copying and distributing a third party's digital content. While imitation may indicate flattery, imitation without permission may be more likely to elicit a demand to cease and desist than to elicit gratitude.

Jim Black may reached at jimb@jrb.com.

© James R. Black 1997
applet by New Media Marketing Lab at Sun Microsystems, Inc.