ing individual fiber repeater/extenders 10BASE-FB AND FP In addition to 10BASE-F, there are two related specifications: 10BASE-FB and 10BASE-FP. 10BASE-FB, where the letter "B" denotes a synchronous signaling backbone segment, provides users with the ability to exceed the "4" in the Ethernet 5-4-3 rule. That rule specifies that a maximum of five Ethernet segments can be joined through the Figure 5.10 A schematic of a FOIRL or 10BASE-F repeater/extender. 10BASE-T modular FOIRL or optical connection 10BASE-F connectors Repeater/Extender Team-Fly® Fiber in the LAN use of a maximum of four repeaters, with a maximum of three popu- lated Ethernet segments between two stations on a LAN. A 10BASE-FB signaling repeater is commonly used to connect repeater hubs together in a repeated backbone network infrastructure that can span multiple 2000-m links. The third version of 10BASE-F is referred to as 10BASE-FP, where "P" denotes the fact that the end segment is a fiber-passive system. Under 10BASE-FP specifications, a single fiber-optic passive-star coupler can be used to connect up to 33 stations that can be located up to 500 m from a hub via the use of a shared-fiber segment. CABLE SUPPORT Both 10BASE-F and FOIRL support several types of multimode optical cable, ranging from 50/125 through 100/140. Table 5.2 compares optical attenuation values for six types of multimode optical cable. Note that 10BASE-FL has a higher loss budget than FOIRL for each type of fiber, explaining why the transmission distance of 10BASE-FL optical repeaters exceeds the distance obtainable using FOIRL repeaters. 100BASE-FX In the wonderful world of Fast Ethernet, 100BASE-FX is the standard that defines Fast Ethernet transmission over fiber-optic media. The 100BASE-FX standard specifies the use of two-strand 625/125- um multimode optical fiber. The actual encoding of data is based on the use of 4B5B coding, which was first used by FDDI and is also used by 100BASE-TX; the latter requires two pairs of category 5 shielded twisted- pair (STP) cable. 10