The Fiber Optics Illustrated Dictionary - Part 65 fills a gap in the literature by providing instructors, hobbyists, and top-level engineers with an accessible, current reference. From the author of the best-selling Telecommunications Illustrated Dictionary, this comprehensive reference includes fundamental physics, basic technical information for fiber splicing, installation, maintenance, and repair, and follow-up information for communications and other professionals using fiber optic components. Well-balanced, well-researched, and extensively cross-referenced, it also includes hundreds of photographs, charts, and diagrams that clarify the more complex ideas and put simpler ideas into their applications context | Fiber Optics Illustrated Dictionary medium if there is only one . This layer supports multiple downstream and upstream channels. Devices such as network bridges are associated with the MAC layer or sublayer in OSI . Mechanical Fiber Splice For a mechanical splice to be effective the fiber filament ends must be precisely cleaved and aligned to form a continuous lightpath without gaps or particles that could cause back reflection top . The joint must be firmly secured within a sturdy supporting structure . the Corning Cable Systems CamSplice to maintain the position of thefilaments relative to one another bottom . Mechanical splicing is only recommended for joints that are well protected from strain and temporary joints such as patch panels that require frequent reconfiguration. For permanent splices fusion splicing is generally preferred. Media Access Control address MAC address A MAC address is an important routing statistic widely used for managing data network transmissions. Route-related devices typically keep a list or table of MAC addresses which may be static or dynamic. Dynamic MAC address lists may be updated in a variety of ways depending on the stability of the configuration of a network and the size of a network. The MAC address is used by a network bridge to determine whether a packet is to be forwarded. By copying an incoming source address to a MAC address table the bridge builds up a port-related picture of device locations on the network. Since there are usually efficiency trade-offs on large networks with machines being added and removed and MAC address tables becoming large and unwieldy certain balancing mechanisms are built into bridge management. By limiting the lifespan of a MAC address the system can be tuned to best serve the needs of the network. Thus a dynamic MAC address that has not been used for a long time will be removed until a transmission is again received from that source. Low-use special purpose addresses . emergency systems
