Cabletron Systems MRX Installation Manual

Cabletron Systems MRX Installation Manual Manual pdf 16 page image

REQUIREMENTS/SPECIFICATIONSPage 2-5• Budget and Propagation Delay - When determining themaximum fiber optic cable length, the fiber optic budget delayand total network propagation should be calculated and takeninto consideration before fiber optic cable runs are incorporated inany network design. Fiber optic budget is the combination of theoptical loss due to the fiber optic cable, in-line splices, and fiberoptic connectors. Propagation delay is the amount of time it takesa packet to travel from the sending device to the receiving device.• Length - The maximum allowable fiber optic cable length is 2km. However, IEEE 802.3 specifications allow for a maximum of1 km.2.3.3 Thin-Net Network RequirementsWhen connecting a Thin-net segment to the HUB with a Single PortCoax Interface Module (SPIM-C), the following network requirementsmust be met:• Cable Type - 50 ohm RG-58A/U type coaxial cable must be usedwhen making up a thin-net cable segment.• Length - The thin-net segment must be no longer than185 meters.• Terminations - A 50 ohm terminator must be connected to thefar end of each thin-net segment.• Connections - A maximum of 29 tee-connectors may be usedthroughout the length of cable segment for host connections. Ifan excessive number of barrel connectors are used within thecable segment, such as finished wall plates with BNC feed-throughs, then a reduced number of host connections may berequired. For special network design, contact Cabletron SystemsTechnical Support.• Grounding - For safety, only one end of a thin-net segmentshould be connected to earth ground. Connection to earth groundat more than one point on the segment could produce dangerousground currents.