Cabletron Systems MRXI-22 User Manual

Contents

INSTALLATION REQUIREMENTS/SPECIFICATIONS2-5• Fiber optic budget is the combination of the optical loss due to the fiberoptic cable, in-line splices, and fiber optic connectors (the loss for eachsplice and connector is typically 1 dB or less).• Propagation delay is the amount of time it takes a packet to travel fromthe sending device to the receiving device. Total propagation delayallowed for the entire network is 25.6 μsec. If the total propagationdelay between any two nodes on the network exceeds 25.6 μsec, thenbridges should be used.• When using single mode fiber optic cable, segment lengths up to 10km are possible if system budgets are met. However, IEEE 802.3FOIRL specifications allow for a maximum length of 1 km.2.3.4 Thin-Net Network RequirementsWhen you connect a Thin-net segment to the MRXI with a Coax InterfaceModule (EPIM-C), the following network requirements must 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 than 185 meters.• Terminations - A 50 ohm terminator must be connected to the far endof each thin-net segment.• Connections - A maximum of 29 tee-connectors may be usedthroughout the length of cable segment for host connections. If anexcessive number of barrel connectors are used within the cablesegment, such as finished wall plates with BNC feed-throughs, then areduced number of host connections may be required. For specialnetwork design, contact Cabletron Systems Technical Support.• Grounding - For safety, only one end of a thin-net segment should beconnected to earth ground. Connection to earth ground at more thanone point on the segment could produce dangerous ground currents.The BNC ports of the Coaxial Interface Modules are not connected toearth ground.Warning: Do not connect the shield at both ends of a thin net segment toground. Only one end of the shield should be connected to earth ground.Multiple ground paths can introduce noise or a hazardous voltagepotential onto the cable.