Cabletron Systems ESXMIM Installation Manual

Also see for ESXMIM: Management guide

Contents

Cabletron Systems ESXMIM Installation Manual Manual pdf 70 page image

Appendix D: Ethernet Cabling RequirementsD-4ESXMIM/ESXMIM-F2 Installation GuideNetwork propagation delay is the amount of time it takes a packet totravel from the sending device to the receiving device. Totalpropagation delay allowed for the entire network must not exceed25.6 μs in one direction (51.2 μs round trip). If the total propagationdelay between any two nodes on the network exceeds 25.6 μs, youmust use bridges or switches.• Length: The maximum possible multimode fiber optic cable length is2 km (1.24 miles). However, IEEE 802.3 FOIRL specifications specifya maximum of 1 km (0.62 miles).D.1.3 Single Mode Fiber Optic NetworkWhen connecting a single mode fiber optic link segment to a hub (usingan EPIM-F3), ensure the network meets the following requirements:• Cable Type: Fiber optic link segments should consist of 8/125 or12/125 μm single mode fiber optic cabling. You can also use62.5/125 μm multimode cable with the EPIM-F3; however, multimodecable allows for greater optical loss, and limits the possible distance to2 km.• Attenuation: You must test the fiber optic cable with a fiber opticattenuation test set adjusted for a 1300 nm wavelength. This testverifies that the signal loss in a cable falls within the acceptable levelof 10.0 dB or less for any given single mode fiber optic link.• Budget and Propagation Delay: When you determine a maximumfiber optic cable length, you must calculate and consider the fiber opticbudget (a total loss of 10.0 dB or less between stations) and totalnetwork propagation delay.To determine the fiber optic budget, combine the optical loss due tothe fiber optic cable, in-line splices, and fiber optic connectors.Typical loss for a splice and connector (together) equals 1 dB or less.Network propagation delay is the amount of time it takes a packet totravel from the sending device to the receiving device. Totalpropagation delay for the entire network must not exceed 25.6 μs inone direction (51.2 μs round trip). If the total propagation delayexceeds 25.6 μs, you must use bridges or switches to re-time thesignal.