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Practical TCP/IP and Ethernet Networking- P16

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Practical TCP/IP and Ethernet Networking- P16: The transmitter encodes the information into a suitable form to be transmitted over the communications channel. The communications channel moves this signal as electromagnetic energy from the source to one or more destination receivers. The channel may convert this energy from one form to another, such as electrical to optical signals, whilst maintaining the integrity of the information so the recipient can understand the message sent by the transmitter | Ethernet networks 57 3.11.4 Maximumtransmissionpath The maximum transmission path is made of five segments connected by four repeaters. The total number of segments can be made up of a maximum of three coax segments containing station nodes and two link segments having no intermediate nodes. This is summarized as the 5-4-3-2 rule. These link segments are 10BaseFL fiber links as specified in IEEE 802.3. 5 segnents 5 segments 4 repeaters 4 repeaters 3 coax segments OR 3 link segments 2 link segnents 2 coax segnents Table 3.3 5-4-3-2 rule It is important to verify that the above transmission rules are met by all paths between any two nodes on the network. Link Link Figure 3.9 Maximum transmission path Note that the maximum sized network of four repeaters supported by IEEE 802.3 can be susceptible to timing problems. The maximum configuration is limited by propagation delay. Note that 10Base2 segments should not be used to link 10Base5 segments. 3.11.5 Maximum network size 10Base5 2800 m node to node 5 x 500 m segments 4 repeater cables 2 AUI 10Base2 925 m node to node 5 x 185 m segments 10BaseT 100 m node to hub 3.11.6 Repeater rules Repeaters are connected to transceivers that count as one node on the segments. Special transceivers are used to connect repeaters and these do not implement the signal quality error test SQE . Fiber optic repeaters are available giving up to 3000 m links at 10 Mbps. Check the vendor s specifications for adherence with IEEE 802.3 repeater performance and compliance with the fiber optic inter repeater link FOIRL standard. 58 Practical TCP IP and Ethernet Networking 3.11.7 Cablesystemgrounding Grounding has safety and noise connotations. IEEE 802.3 states that the shield conductor of each coaxial cable shall make electrical contact with an effective earth reference at one point only. The single point earth reference for an Ethernet system is usually located at one of the terminators. Most terminators for Ethernet have a screw terminal to .