IBM 8285 Nways, Инструкция по установке и эксплуатации

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Optical Power Budget
When validating cabling distances in workgroup switch 155Mbps links, network planners and installers
should calculate for maximum optical power losses in each end-to-end connection. Table 11 and
Table 12 on page 201 do this for you by taking the minimum amount of power that can be transmitted
and the maximum amount of power that can be received for different types of fiber cable.
The optical power budget for the workgroup switch port-to-port or port-to-device connection is shown in
the column on the far right-hand side of each table. By not exceeding this value, you can ensure the
integrity of the ATM connections you create.
The Optical Power Budget value shows the amount of optical power left to compensate for power losses
from connectors, splices, patch panels, and so on (see the following sections) in each workgroup switch
link of an ATM connection. In order for an workgroup switch 155Mbps link to transmit ATM data
effectively, the optical power budget must be greater than the total power loss.
When taking the optical power budget for an ATM link between an workgroup switch port and an end
user device, be sure to use the values specified in the
ATM User-Network Interface (UNI) Specification
V3.1, ATM Forum. These values are shown in Table 11 on page 201.
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IBM 8285 Nways ATM Workgroup Switch: Installation and User’s Guide