It is not practical or necessary to test all of your links for Alien Crosstalk compliance.
The TIA does not specify a sampling plan. However, ISO/IEC 14763-2 (Draft) has defined a sampling plan for disturbed (victim) links of:
| Installation size (No. of total links) | Sample size (No. of links to test) |
| 3 – 33 | 100% |
| 34 – 3,200 | 33 |
| 3,201 – 35,000 | 126 |
| 35,001 – 150,000 | 201 |
| 150,001 – 500,000 | 315 |
You are required to test an equal number of short, medium and long disturbed (victim links). ISO/IEC 61935-1 states that if three of the shortest, three of the medium and three of the longest links exceed 5 dB in margin, the user can opt to stop testing,
DO NOT choose a disturbed (victim) link which is at the end of a row of connectors. This is not worst case.
DO select a long disturbed (victim) link that has at least one connector immediately adjacent to it in the patch panel.
Once you have chosen your disturbed (victim) link, your disturbers should be cables in the same bundle. The disturbers are the cables you will energize. Alien Crosstalk across cable bundles is not considered significant.
Experience tells us that most of the Alien Crosstalk comes from the connectors. So it makes sense to have the connectors above and below as disturbers.
Learn About: