Do CAT5e structure weaken Voice signal when RJ-61 termination is used? RJ-45 & RJ-61 does have different pins termination. Straight-A, Straight-B, Cross-Over (A & B each end) for RJ-45 (Data). Paired at middle going out method meaning 4 & 5 pin + 3 & 6 pin, and so on for RJ-61 (Voice). In Cat5e (Data) when you do not follow Straight-A/Straight-B crimp method. The signal may not reach 100m if you used something else. Since RJ-61 (for Voice) is a different pins termination, I use CAT6 instead. Here's where I'm not sure though... Is CAT5e inferior over CAT6 because of structure when you use RJ-61 termination (Voice)? Or is it actually better?

Data (ethernet) uses pair-wise 1/2, 3/6, 4/5, and 7/8. Your voice wiring -- 4/5, 3/6, _2/7, 1/8_ \-- creates _split-pairs_. That's why it doesn't work well for data. The category rating of the cable (which is a measure of attenuation, frequency, and cross talk) won't make any difference if the differential signal is riding different pairs.