Справочник Пользователя для Cabletron Systems 8H02-16
Network Requirements
8H02-16 User’s Guide
2-3
Propagation Delay
Propagation delay is the amount of time it takes data to travel from the
sending device to the receiving device.
sending device to the receiving device.
Total propagation delay allowed for a 100BASE-TX (100 Mbps) network
is 256 bit times or 2.56 microseconds (2.56
is 256 bit times or 2.56 microseconds (2.56
µ
s). If the total propagation
delay between any two nodes on a 100BASE-TX network exceeds
2.56
2.56
µ
s, then use bridges or other devices to further segment the network.
Total propagation delay allowed for a 10BASE-T (10 Mbps) network is
256 bit times or 25.6
256 bit times or 25.6
µ
s. If the total propagation delay between any two
nodes on a 10BASE-T network exceeds 25.6
µ
s, then use bridges or other
devices to further segment the network.
Temperature
The attenuation of PVC insulated cable varies significantly with
temperature. At temperatures greater than 40
temperature. At temperatures greater than 40
°
C (104
°
F), use plenum rated
cables to ensure that cable attenuation remains within specification.
2.1.3
100BASE-FX Fiber Optic Network
Ports 15 and 16 of the 8H02-16 support the Cabletron Systems FE-100FX
fiber optic interface module. The FE-100FX meets the IEEE 802.3u
standard. When connecting a fiber optic segment to the 8H02-16, the
network must meet the following requirements:
fiber optic interface module. The FE-100FX meets the IEEE 802.3u
standard. When connecting a fiber optic segment to the 8H02-16, the
network must meet the following requirements:
Cable Loss
Test the fiber optic cable with a fiber optic attenuation test set adjusted for
an 850 nm wavelength. This test verifies that the signal loss is within an
acceptable level. The maximum loss for a multimode cable is 11.0 dB.
an 850 nm wavelength. This test verifies that the signal loss is within an
acceptable level. The maximum loss for a multimode cable is 11.0 dB.
Fiber Optic Budget and Propagation Delay
Determine the maximum fiber optic cable length by calculating the fiber
optic budget delay and total network propagation before fiber optic cable
runs are incorporated in any network design.
optic budget delay and total network propagation before fiber optic cable
runs are incorporated in any network design.
Fiber optic budget is the combination of the optical loss due to the fiber
optic cable, in-line splices, and fiber optic connectors.
optic cable, in-line splices, and fiber optic connectors.