Cabletron Systems TPXMIM-20 Installation Manual

Also see for TPXMIM-20: Addendum manual

Cabletron Systems TPXMIM-20 Installation Manual Manual pdf 23 page image

CHAPTER 2: SPECIFICATIONS/REQUIREMENTSPage 16TPXMIM Installation Guide• Length - The maximum possible multimode fiber optic cable lengthis 2 km (2187.2 yards). However, IEEE 802.3 FOIRL specificationsspecify a maximum of 1 km (1093.6 yards).2.3.3 Single Mode Fiber Optic NetworkWhen connecting a single mode fiber optic link segment to the hub (usingan EPIM-F3), ensure the network meets the following requirements:• Cable Type - Fiber optic link segments should consist of 8/125 to12/125 μm single mode fiber optic cabling. You can also use 62.5/125 μm multimode cable with the EPIM-F3; however, use ofmultimode cable causes greater optical loss, and limits the possibledistance to 2 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 themaximum fiber optic cable length to incorporate fiber runs into yournetwork, you must calculate and consider the fiber optic budget (atotal loss of 10.0 dB or less is permissible 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 μsecin one direction (51.2 μsec round trip). If the total propagation delayexceeds 25.6 μsec, you must use bridges.