Cabletron Systems EMM-E6 Ethernet manual Single Mode Fiber Optic Network

Models: EMM-E6 Ethernet

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NETWORK REQUIREMENTS

2.1.3Single Mode Fiber Optic Network

When connecting a single mode fiber optic link segment to the hub (via EPIM-F3), ensure the network meets the following requirements:

Cable Type - Fiber optic link segments should consist of 8/125 to 12/125 ∝m single mode fiber optic cabling. You can also use 62.5/125 ∝m multimode cable with the EPIM-F3; however, multimode cable has greater optical loss, and limits the possible distance to 2 km.

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 the maximum fiber optic cable length to incorporate fiber runs into your network, you must calculate and consider the fiber optic budget (a total loss of 10.0 dB or less is permissible between stations) and total network propagation delay.

To determine the fiber optic budget, combine the optical loss due to the 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 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.

Length - If you meet all system budgets, the maximum single mode fiber optic cable length can reach 5 km (3.1 miles) with bridges at each segment end. However, IEEE 802.3 FOIRL specifications specify a maximum of 1 km (1093.6 yards).

EMM-E6 User’s Guide

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Cabletron Systems EMM-E6 Ethernet manual Single Mode Fiber Optic Network