My one memorable story on this... It is a good lesson so I will share it.
We did a "remote" install of about 50 phones once, not long ago, sometime last winter... Shipped the phones and all they had to do was plug them in and PIN them, their IT staff had done it numerous times before and never been a problem. This was probably the 3rd or 4th decent sized site they had deployed the devices themselves. We didn't expect any issues, new building, new cable, labeled, tested, quality switches, well defined network, etc. Should have been a simple thing.
At this site though, about 20 of the phones came right up, and the other 30 all sat on the "Waiting for LAN link to come up screen". Worked with them trying different ports, switches, cables, etc. All the runs were tested and certified CAT-6 by a knowledgeable contractor. We could not find the cause, but taking several phones directly to the switches and connecting them with multiple patch cords failed too, but yet some worked at the switch and not at the desktop. Seemed to be either multiple issues or a root one we couldn't narrow down.
So after a conference call with a couple other techs, my manager, and the customer's IT manager on Monday morning, I load up a couple cases of phones, switches, patch cords, etc... and drove 4-5 hours to the site. First inspection matched all remote testing.
The odd part here was the patch cords, both at the switch and at the phone, just felt "weird" to me... I can't really explain it, they just felt odd. So I asked where the patch cords that came with the phones were and they had them in a box in the back. After grabbing a few phones and using the factory patch cords at the switch, all worked. After grabbing them and a few quality longer patch cords from my van, between myself and the IT staff we got another 15 or so working by replacing all the patch cords at the phones. Finally wound up replacing patch cords at the switch with ones from my van, and all phones worked.
It was the patch cords... both at the switch -AND- at the phone, more failed than worked, although almost all of the patch cords passed the "PC test" when connected to a computer.
End result after talking to the IT person on site, they tried to save a few hundred bucks by ordering patch cords on eBay because they wanted specific colors and it was "too expensive" to get them locally, but they wound up having to replace all of them and it cost them way more in the end... Especially with a 15 hour service call on top of the price of the patch cords and their replacements.
So basically they spent I don't know how many hundreds of thousands of dollars, maybe millions, on a new facility and infrastructure but someone thought it would be a good idea to save a few hundred dollars on patch cords. It wound up costing them more in the end. Did it really amount to much in the grand scheme of things? I don't know, but if they would have stuck with their "normal" suppliers and ponied up the extra few hundred dollars up front, this all would have been avoided.
