Appendix C: Ethernet Cabling Requirements
Network propagation delay is the amount of time it takes a packet to travel from the sending device to the receiving device. Total propagation delay allowed for the entire network must not exceed
25.6 ∝s in one direction (51.2 ∝s round trip). If the total propagation delay between any two nodes on the network exceeds 25.6 ∝s, you must use bridges or switches.
•Length: The maximum possible multimode fiber optic cable length is 2 Km (1.24 miles). However, IEEE 802.3 FOIRL specifications specify a maximum of 1 Km (0.62 miles).
C.1.3 Single Mode Fiber Optic Network
When connecting a single mode fiber optic link segment to a hub (using an
•Cable Type: Fiber optic link segments should consist of 8/125 or 12/125 ∝m single mode fiber optic cabling. You can also use 62.5/125 ∝m multimode cable with the
•Attenuation: You must test the fiber optic cable with a fiber optic attenuation test set adjusted for a 1300 nm wavelength. This test verifies that the signal loss in a cable falls within the acceptable level of 10.0 dB or less for any given single mode fiber optic link.
•Budget and Propagation Delay: When you determine a maximum fiber optic cable length, you must calculate and consider the fiber optic budget (a total loss of 10.0 dB or less between stations) and total network propagation delay.
To determine the fiber optic budget, combine the optical loss due to the fiber optic cable,
Network propagation delay is the amount of time it takes a packet to
travel from the sending device to the receiving device. Total propagation delay for the entire network must not exceed 25.6 ∝s in one direction (51.2 ∝s round trip). If the total propagation delay exceeds 25.6 ∝s, you must use bridges or switches to
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