Fiber Optic CableWritten by Gianfranco Fracassi
Fiber Optic Cable Fiber optic cabling consists of a centre glass core surrounded by several layers of protective materials (See fig. 5). It transmits light rather than electronic signals eliminating problem of electrical interference. This makes it ideal for certain environments that contain a large amount of electrical interference. It has also made it standard for connecting networks between buildings, due to its immunity to effects of moisture and lighting. Fiber optic cable has ability to transmit signals over much longer distances than coaxial and twisted pair. It also has capability to carry information at vastly greater speeds. This capacity broadens communication possibilities to include services such as video conferencing and interactive services. The cost of fiber optic cabling is comparable to copper cabling; however, it is more difficult to install and modify. 10BaseF refers to specifications for fiber optic cable carrying Ethernet signals.
| | Do We Need Web Directories?Written by Stuart C. McHenry
WEB DIRECTORIES Directories play an important role in aiding a site’s web visibility. Crawler-based search engines will, upon finding your site on a directory, or series of directories, consider these directories as one-way links. This will then add importance to your site’s relevance in “eyes” of these search engines and will most likely increase chances of your site being added to their listings. Relevant reciprocal link exchanges are given some importance by search engines but most valued links, those which are most likely to boost a sites rankings in major SES are one-way links - sites that accept your link without requiring a reciprocal link from you. These links are highly regarded due to reasoning that other sites must hold your site in high enough esteem that having your link on their site is acceptable without an exchange requirement. Consequently, more one-way links, better! Few, if any, sites today will agree to a one-way link favoring your site. The only way to achieve this is thru submitting to web directories. Web directories and search engines have made a conscious effort to exclude bulk submitters. You’ve seen ads - “We submit to 1,500 search engines and directories for $10.00, etc.” For this reason, many directories require your registration and possibly entering a security code. Practically all of these directories require you provide an email address. Although hot mail or gmail is usually accepted, some directories will require an email corresponding to your domain name and will allow you to submit your site only after verification so it is best to establish an email specifically for web submissions.
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