Here are some of the remarkable problems I've had with WiFi (wireless Ethernet) implementations. They're peculiar, unexpected, and hopefully, someone other than myself can learn from them.
A client of mine operates a retail location in a storefront on the ground floor of a condominium complex. He wanted to install some WiFi security cameras. I tried to convince him that a wired system would be much more reliable, but he was adamant. I surveyed the WiFi coverage area and found many WiFi access points, no doubt from the condominiums upstairs, and configured the WAPs and cameras appropriately. I installed wireless access points at strategic locations and WiFi video cameras covering the entrances and the registers, and the system worked fine.
... until the next day. The cameras weren't connected to the wireless access points. I restarted some of them, but they still wouldn't connect. I restarted the WAPs, but still no luck. I did another survey of the WiFi environment and found that it had changed significantly from the previous day. I reconfigured the WAPs and cameras to operate well clear of the new environment, so our devices wouldn't interfere with the others, and the others wouldn't interfere with ours.
... until the following day. The environment had changed again!. About half of the WiFi hotspots in the condos above were Verizon, the other half Comcast. I had hoped to identify some common characteristic among the hotspots that were changing, to narrow down the ones i had to worry about, but could see nothing.
After weeks of monkeying around with this setup, I couldn't ever come up with a configuration that worked reliably.
Same client. Same location. Different problem.
As often happens around here during the Summer months, afternoon thunderstorms bring with them power failures and power interruptions. These are a problem for computers and their associated devices under the best of circumstances, but they usually recover well. Not so, this wireless network. The cameras, of course, were not protected by UPSs, but, unfortunately, neither were the WAPs. When the power went out, both the cameras and the WAPs failed. The cameras started up quickly, but the WAPs took more time. The cameras couldn't find WAPs to connect to, and stopped trying!
When the WAPs finally came up, the cameras had stopped trying to connect. Every time this happened (sometimes several times a day), the owner had to trip the circuit breakers the cameras were on, so they would come back up when the WAPs were available.
Both the cameras and the WAPs were from the same manufacturer. I conferred with their Technical Support, who tested the setup and confirmed the problem that the cameras only tried once to connect to a WAP, but had no solution. The owner had to get UPSs for each WAP.
The good news is that the cameras also couldn't connect to any of the other WiFi network in the area, presumably since those WAPs weren't protected by UPSs either.
Another client has a business location only about 50 feet from her home. (Nice commute, huh?) Both locations are serviced by their own Verizon FiOS connection. She uses the WiFi network in her home, but only uses the wired network at her work. She has a laptop computer that she uses while on the road, in her home, and at work. At home, she connects via WiFi, but at work she connects via a CAT5 Ethernet cable. When she returns from being on the road, she needs to synchronize data files on her laptop with the same files on the office computer. For some reason, the synchronization stopped working.
It turns out that the two Verizon technicians that installed the FiOS equipment in each location, both used the same IP configuration for each network. Also, it turns out, the laptop was still connected to the home wireless network while it was trying to use the wired network at work. Further, it turns out the laptop was assigned the same IP address on the home WiFi network as the office computer was using on the wired network. (What are the odds of that?) As a result, any attempt to have the laptop communicate with the office computer resulted in the laptop computer communicating with itself. Since the laptop was trying to synchronize with itself, the process went very quickly.The only indication that anything was wrong was that, after what appeared to be a successful synchronization on the laptop, the office computer still had different data than the laptop.
It turns out that, once I figured out that it wasn't the synchronization that was failing, but the network, it didn't take long to fix the problem.
© 2013 T C Solutions, Inc.