 for a coax segment is 2165 nsec. 2. A point-to-point link constitutes a link segment. A link segment may contain a max- imum end-to-end propagation delay of 2570 nsec and shall terminate in a repeater set at each end. It is not permitted to connect stations to a link segment. 3. Repeater sets are required for segment interconnection. Repeater sets occupy MAU positions on coax segments and count toward the maximum number of MAUs on a coax segment. Repeater sets may be located in any MAU position on a coax segment but shall only be located at the ends of a link segment. 4. The maximum length, between driver and receivers, of an AUI cable is 50 m. The propagation velocity of the AUI cable is assumed to be 0.65c minimum. The maximum allowable end-to-end delay for the AUI cable is 257 nsec. The maximum transmission path permitted between any two stations is five seg- ments, four repeater sets (including optional AUIs), two MAUs, and two AUIs. Of the five segments, a maximum of three may be coax segments; the remainder are link segments. The maximum transmission path consists of 5 segments, 4 repeater sets (with AUIs), 2 MAUs, and 2 AUIs, as shown in Figure 11.9. If there are two link segments on the transmission path, there may be a maximum of three coaxial cable segments on that path. If there are no link segments on a transmission path, there may be a maximum of three coaxial cable segments on that path given current repeater technology. Figure 11.10 shows a large system with maximum length transmission paths. It also shows the application of link segments versus coaxial cable segments. The bitter ends of coaxial cable segments are iSEG2, ISEG4, AUI 1 AUI 2 Repeater Repeater Repeater Repeater Station Station Figure 11.9 Maximum transmission path. 4Where C = velocity of light in a vacuum. ENTERPRISE NETWORKS I: LOCAL AREA NETWORKS REFERENCE CSMA/CD MODEL LAYERS LAYERS HIGHER LAYERS APPLICATION LLC-LOGICAL LINK CONTROL PRESENTATION MAC-MEDIA ACCESS CONTROL SESSION RECONCILIATION 100BASE-T Baseband TRANSPORT Repeater 