- Cisco ONS 15454 Manual

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Cisco ONS 15454 Installation and Operations Guide
November 2001
Chapter 1 Hardware Installation
Cable Routing and Management
Figure 1-35 Fold-down front door of the cable-management tray (displaying the cable routing
channel)
1.14.2 Coaxial Cable Management
Coaxial cables connect to EIAs on the ONS 15454 backplane using cable connectors. EIAs feature
cable-management eyelets for tie wrapping or lacing cables to the cover panel.
Procedure: Route the Coaxial Cables
Step 1 Tie wrap or lace the coaxial cables according to local site practice and route the cables through the side
cutouts on either side of the ONS 15454. The rubber coated edges of the side cutouts prevent the cables
from chafing.
Note When using the RG179 cable with SMB connectors, remember that the maximum distance
available with the RG179 cable is less than the maximum distance available with standard
RG59 cable. If you only use the RG179, the maximum available distance is 50 feet versus
the 450 feet available with the larger RG59 cable.
Step 2 Use short lengths of “pigtail” RG179 to terminate the shelf assembly.
Step 3 Use standard RG59 connected to the RG179 for the remainder of the cable run. When using a 10-foot
section of the RG179, you can attach a maximum length of 437 feet of RG59. When using a 30-foot
section of RG179, you can attach a maximum length of 311 feet of RG59.
The shorter maximum distance available with the RG179 is due to a higher attenuation rate for the
thinner cable. The attenuation rate for RG59 cable (based on testing with Belden 923, the equivalent of
328A cable) is ~1.0 dB/100 feet at 22 Mhz (DS-3 data rate). The attenuation rate of RG179 is
6.3 db/100 feet. Use a figure of 5.0 for total cable loss when making calculations. Figure 1-36 shows one
side of the ONS 15454 backplane with SMB EIAs and the coaxial cables properly routed.
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