![background image](http://html2.mh-extra.com/html/ibm/8265/8265_site-preparation-manual_3405523052.webp)
36
IBM 8265: Planning and Site Preparation Guide
Verifying ATM Fiber Connections
To verify that a fiber connection is valid for ATM data transmission, you check that the
total power loss for a given link is less than the optical power budget for that link.
In the previous example, the total power losses for each link were:
The links between ATM Desktop A and 8265B, and 8265 C to ATM Desktop D are
valid, because the total power loss for the link is less than the optical power budget for
that link.
The link between 8265 B and 8265 C is invalid, because the total power loss is greater
than the power budget. If the link used singlemode fiber instead of multimode fiber,
then the connection would be valid because the power budget would be 13 (see Table
37 on page 59.
Maintaining Fiber Connections
After calculating the optical power loss for links and allowing for ‘worst case’
scenarios, the data transmission in the ATM connections in your network should be
reliable. To ensure that the optical power transmission does not exceed the optical
power budget and disrupt the quality of data transmission for your current fiber
configuration, IBM recommends that you:
•
Do not install additional links (for example, patch panels or jumper cables) in each
connection without verifying that the additional link will not cause the optical power
budget to be exceeded.
•
Maintain the homogeneity of links by using the same category of fiber cable for
each link of a connection.
•
When the margin between the total power loss on a connection and the optical
power budget is less than, or equal to, 1 dB, check with your vendor to make sure
you are using the power loss value set by the manufacturer for your cable, and
recalculate the total power loss including the variance value for each component.
The variance value for each optical fiber component (splices, connectors, cables,
and so on) is given in previous sections of this chapter.
Table 26. Verifying Fiber Link Validity (Example)
Link
Total Power Loss (dBm)
Optical Power Budget
ATM Desktop A
to
155Mbps Port in 8265 B
5.7 7.0
622Mbps port in 8265 B
to
622Mbps port in 8265 C
10.05 6.0
155Mbps port in 8265 C
to
ATM Desktop D
6.25
7.0
Summary of Contents for 8265
Page 1: ...8265 Nways ATM Switch Planning and Site Preparation Guide GA33 0460 0 IBM...
Page 2: ......
Page 3: ...8265 Nways ATM Switch Planning and Site Preparation Guide GA33 0460 01 IBM...
Page 8: ...vi IBM 8265 Planning and Site Preparation Guide...
Page 10: ...viii IBM 8265 Planning and Site Preparation Guide...
Page 14: ...xii IBM 8265 Planning and Site Preparation Guide...
Page 16: ...xiv IBM 8265 Planning and Site Preparation Guide...
Page 26: ...10 IBM 8265 Planning and Site Preparation Guide...
Page 38: ...22 IBM 8265 Planning and Site Preparation Guide...
Page 70: ...54 IBM 8265 Planning and Site Preparation Guide...
Page 118: ...102 IBM 8265 Planning and Site Preparation Guide...
Page 121: ...Copyright IBM Corp 1994 1998 105 Appendix C Blank Planning Charts...
Page 122: ...106 IBM 8265 Planning and Site Preparation Guide...
Page 123: ...Appendix C Blank Planning Charts 107...
Page 124: ...108 IBM 8265 Planning and Site Preparation Guide...
Page 126: ...110 IBM 8265 Planning and Site Preparation Guide...
Page 128: ...112 IBM 8265 Planning and Site Preparation Guide...
Page 130: ...114 IBM 8265 Planning and Site Preparation Guide...
Page 132: ...116 IBM 8265 Planning and Site Preparation Guide...
Page 134: ...118 IBM 8265 Planning and Site Preparation Guide...
Page 136: ...120 IBM 8265 Planning and Site Preparation Guide...
Page 138: ...122 IBM 8265 Planning and Site Preparation Guide...
Page 140: ...124 IBM 8265 Planning and Site Preparation Guide...
Page 142: ...126 IBM 8265 Planning and Site Preparation Guide...
Page 144: ...128 IBM 8265 Planning and Site Preparation Guide...
Page 146: ...130 IBM 8265 Planning and Site Preparation Guide...
Page 148: ...132 IBM 8265 Planning and Site Preparation Guide...
Page 152: ...136 IBM 8265 Planning and Site Preparation Guide...
Page 163: ......