Speaking as a member of the in-house IT/Telecom team for a rather large firm (offices in 14 cities around the globe and 6,500+ phones), we have demanded Cat5 (5e)& RJ45s. They are not color coded; all jacks are white. Our rationale is basically to allow us to 'repurpose' a jack at any time.
All offices are cabled in a very uniform manner. Each "drop" is ALWAYS a 4 port drop, with the exception being wall phones in the elevator lobbies. The 4 port face place is labeled with a Floor # and "Drop #" -- so a cable plugged into the third port on the quad "21-014" indicates it terminates to the 21st floor IDF, jack #014, and being the 3rd port, it will go to the "C" patch panel.
In the IDF, we can can patch that to either a network switch, a voice riser patch panel, ISDNs (legacy VTC equipment), or even to a serial port, as needed. Traditionally, the first jack ("A") on the quad is always a the phone. The last port ("D") is data. As additional data ports are needed, they move to C, then to B.
The legacy PBXes were cross-connected at a 110 block to the Voice Riser patch panels.
This flexibility allowed us to transition our offices from legacy TDM PBXes (Nortel Meridian Option 11c / 61c) to a VoIP solution quickly and easily -- no additional cable drops needed. On the night of the cutovers, only thing needed was to move patch cables from the voice riser patch panel to the new VoIP VLAN switches while a tech swapped out the physical phones at the desks. No new cable drops, no changing jacks from RJ11 to RJ45. The transition in each office was pretty quick, smooth and seamless.
Also, we do not ever use the the PC port on the back of a VoIP phone. The issue with using the VoIP phone as a network switch is that if the phone reboots for any reason (i.e. configuration changes), it takes down the PC's network connection until the phone restarts completely. Interrupting a PC's connection, even momentarily, is to be avoided at all costs in our firm.
The idea it to cable for almost any possible need. It is very very rare that we ever have to call a cable vender to add additional drops in any of our offices, after the initial build-out.
We have used this as our firm standard for well over 15 years and I can't think of any reports of damaged equipment resulting from someone making a cabling mistake. Worse case has been reports of "not working" and the local tech comes by and plugs in the device into the correct jack then walks away -- no damage ever.
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