Hello all,
I`m trying to come up with a couple of equations to determine the characteristics of residential networks.
Basically, what I`ve got so far is that the bandwidth is determined by the interval in which PSACR (power sum attenuation to cross talk ratio) has a positive value.
I do realize that bends in the cable will modify the impedance and thus modify the twisted pair characteristics.
So, what I am looking for are the equations (or at least some help in coming up with them) that would give me length and bend (corner) dependencies (for example, if I have a 130m link that has 4 corners, my link will have a bandwidth of X, attenuation of Y and max data rate of Z).
Thanks!
Obviously if you go 110 meters it’s not with the specs, but it should work, although I would not expect it to work at the upper end of the bandwidth i.e., gigabyte speeds. 100Mb is iffy at that distance but 10Mb is almost guaranteed to be ok assuming you don’t have any kinks in the cable.
As a real life example, one of our stores had a few stations (on a mini 10/100 switch) with intermittent connectivity issues and only had a stable connection after forcing 10Mb half duplex. After a little troubleshooting. I discovered that the contractor had pulled a 365ft run for the switch uplink. We pulled a new run (about 200ft) from a closer wiring closet and was then able to have good connection at 100Mb full duplex.
Unless you are working on designing a new cable spec (or if this is for a college course assignment), you’re just wasting your time. I would need to pull out my old books, but if I remember correctly, the sharpest bend radius is 4 times the diameter (or maybe it’s circumference) of the cable. If you go sharper than that, you start running into trouble.
While it is possible to go well beyond the maximum 100 meter distance, it really shouldn’t be done. To our surprise, this last year at a PGA tournament our company hosted, we had a 5,000 ft run of cat 6 that “worked” for a 1.5Mb dsl connection for a limited number of users, but I certainly wouldn’t recommend it.
Just stay within the industry standard specs and if you need to go over the 100 meters for a single run, then use fiber.