Issues with Linksys WAP54G, POE and CAT 6

[batocaster]

A new facility at work just installed a certified CAT 6 network. We set up WAP54G APs with Power Over Ethernet and are experiencing lockups on all APs (three total installed on the LAN) at various times of the day. All switches are Allied-Telesyn Gigabit. No issues with the same devices on CAT 5 installed networks in other facilities.

A quick call to Linksys tech support confirmed they do not support CAT 6, though their manuals all state CAT 5 or higher. I assumed CAT 6 to be "higher" than CAT 5.

Any other users out there successfully running Linksys on CAT 6 in a business LAN environment? Anyone with similar issues or that could confirm CAT 6 just won't work? Any assistance would be appreciated and thanks in advance for your time.

 

[bcastner]

CAT-6 is fully backwards compatible with CAT-5e.

There are two major differences: Signal to noise ratio and the Bandwidth used to test the cable

The first difference is the most important. Cat 6 is twelve times less "noisy", than Cat 5e. When your computer sends data across your network some data packets are lost or corrupted along the way. These packets have to be resent by the system. The better the signal to noise ratio is on your network, the less often this happens.

As computer networks become faster, the signal to noise ratio becomes more important. If the network is racking up packets that must be resent faster than it can resend them, the network may eventually fail or slow to a crawl with the backlog. Using cable and components that have better signal to noise ratios, such as those rated to Cat 6, can help to prevent this potential problem.

As for the testing bandwidth, the official Cat 5e standard calls for testing across a bandwidth of 100 MHz. The Cat 6 standard calls for testing across a bandwidth of 250 MHz. The reality is that most computers and networking equipment only transmit across a frequency range of 100 MHz. (In the future, of course, actual utilization of greater bandwidth may become more common.)

When it comes down to it, however, this particular stat isn't all that important. Many cable companies tout the high bandwidth of their cable. Some even test up to as high as 700 MHz. It sounds great for marketing, but the truth is that the MHz rating is not the same as speed. All cable rated Cat 5e or Cat 6 is capable of Gigabit Ethernet. The MHz rating is just the frequency range used for testing the cable.

If I had to make a guess I would look for the solution to your problems with the POE injection. Linksys POE, for example, injects five volts. Yet the WRT54G and WAP54G since model 1.1 have both required 12 volts.

The result is that they run hotter and run unreliably.