Pushing Maximum Segment Lengths for 10/100Base-T beyond theoretical limitation

Theory limits maximum length between repeater and PC to 100m for both 10 and 100mbps. I tested a 152m run using PVC solid core CAT 5e and did not encounter any propagation delay or data collisions. Tested in both 10 and 100mbps mode.
Theory limits maximum length between terminated wall jack and PC to 3-6m. I tested a 28m run using PVC solid core CAT5e and did not encounter any propagation delay or data collisions. Tested in both 10 and 100mbps mode.
Interesting…

1. RE: Pushing Maximum Segment Lengths for 10/100Base-T beyond theoretical limitation
DJ Net2Infinity May-23-02 05:46 PM
In response to message 0

Yeah it can be done. What methodology did you use to test this, and what is your network setup?

2. RE: Pushing Maximum Segment Lengths for 10/100Base-T beyond theoretical limitation
Flavah May-23-02 06:04 PM
In response to message 1

Collisions are more likely to occur when you go beyond specs. Plus you would see a difference when you are getting legal collisions within the theoritical limitations; Then once you go beyond the limits, what would have been a legal collision could now become an illegal collision.
It takes a big man to cry, but it takes a bigger man to laugh at that man.

4. RE: Pushing Maximum Segment Lengths for 10/100Base-T beyond theoretical limitation
lbyard May-24-02 11:48 AM
In response to message 2

Or, in otherwords, you will not detect a collision if you start transmitting again before the signal indicating that a collision has occurred has had enough time to reach the receiver. I think it would work OK with 10BASE-T, but would be leery of using the configuration for 100BASE-TX. Yes, I think the flexible patch cables can be stretched quite a bit. As I understand it, the main reason for the 3-meter limit is based on the fact that stranded core wire absorbs moisture over time and degrades. I believe I saw that on Cabletron’s web site a long time ago. Remember, all of these specs are based on conservative engineering practices and were written by experienced engineers who know what they are doing. It’s like overclocking a computer. You may get away with it, but I don’t do it or recommend it. Larry