Cabletron Systems SEH-22 User Manual

Also see for SEH-22: User guide

Contents

CABLE SPECIFICATIONSSEH USER’S GUIDE2-3DelayThe maximum propagation delay of a 10BASE-T link segment must notexceed 1000 ns. This 1000 ns maximum delay limits the maximum linksegment length to no greater than 200 meters.CrosstalkCrosstalk is caused by signal coupling between the different cable pairscontained within a multi-pair cable bundle. 10BASE-T transceivers aredesigned so that the user does not need to be concerned about cablecrosstalk, provided the cable meets all other requirements.NoiseNoise is caused by either crosstalk or externally induced impulses.Impulse noise may cause data errors if the impulses occur at very specifictimes during data transmission. Generally, the user need not be concernedabout noise. If noise-related data errors are suspected, it may be necessaryto either reroute the cable or eliminate the source of the impulse noise.TemperatureMulti-pair PVC 24 AWG cables typically have an attenuation of8 to 10 dB/100 meters at 20°C (68°F). The attenuation of PVC insulatedcable varies significantly with temperature. At temperatures greater than40°C (104°F), Cabletron recommends the use of plenum-rated cables toensure that cable attenuation remains within specification.