My immediate impression is that the punchdown is a better connection and a punchdown on both sides would make better connections than modular connector on both sides, and in fact better connections than using modular connectors AT ALL. But it would give no flexibility, so there would be no need for a patch panel. What a patch panel offers over wires going straight to their intended device is flexibility.


Here's the punchdown: It's an IDC or insulation displacement connection. A piece of insulated wire is jammed between two pieces of metal with sharp edges that are spaced such that the insulation is stripped off the wire, but only at the point between the connector blades, jammed so hard that the wire deforms a bit and makes an oxygen-free connection.

Here's the plug: Crimping the connector makes IDC connections of the wires to the plug contacts. The plug and socket then are connected by the pressure between the plug contact and the socket contact.

So... if you had a punchdown on both sides, your connection would be two punchdowns, which are two possible points of failure. If you had a plug and socket on both sides, you'd have two crimps and one place where contacts press against one another, which is three possible points of failure.

The standard setup is a punchdown on one side and a plug/socket on the other side, which has a punchdown, a crimp, and contacts pressing against one another, for a total of three possible points of failure.

Punchdowns on both sides allow for no flexibility, so they're not a great idea in a real system.

It would be harder (for me, anyway) to install plugs onto wires going to the backs of rack panels than it is to punch down the wires. Plus, to get total connection versatility, if you can change the connections on the front of the panel by moving cables, you have full flexibility, so having plugs in the back of the panel offer no wiring advantage.

It seems that a system with punchdowns on the back and sockets and plugs on the front gives the best flexibility.

Thanks for asking. I had never thought this through before.

To those for whom this answer was too long:

Because it would be worse.