Fribble has integrated PCI Ethernet. A regular UTP (10b-T) cable connects from the back of fribble to a jack. But here's where the nastiness begins. The jacks are all RJ-11 6-pin jacks. This is not made for Ethernet- it was intended for serial terminals. There are no other points where a connection can be made, and new jacks would involve lots of wiring from the Telco-50 (Centronics-style) plug to new RJ-45 jacks. If you don't deal with networking and wiring, just believe me that it is less than ideal.
So I improvise- new jacks connected to RJ-11 cables to form convertors.
The black box takes the large grey cable (50 conductor) and splits it into 8 6-pin jacks. This cable is made for telephone use, and as such it isn't really great for Ethernet. It is arranged in 25 pairs, which are twisted once every 6 inches or so. Compare this to good Cat.5 cable, whose pairs are twisted every ½ inch or so. Can you say crosstalk? Attenuation? Oh, just a little bit. Fortunately not enough to cause substantial signal loss.
To improve things somewhat, a recently added cable has a 6-pin RJ connector crimped on instead of the improvised convertor. Eventually, we'll run a single good Cat.5 cable to the room and break it out with a small local hub.
The thing that I think saves the whole installation is the fact that everything runs in cable trays. The grounded metal grid probably shields the worst of the noise from the data wiring. Unfortunately, the cable runs are long and as you might be able to tell below, lots of different cables are all run together- voice, Ethernet, serial, and who knows what else.
These massive bundles of cables run into service corridors, where all the building's utilities converge in one noisy, dirty, dimly-lit place. The data cables run right above a three-phase AC bus which distributes power to this floor. No wonder why you hear a hum at 60Hz and a few harmonics on the phones. Actually, you can hear them just standing under the bus. Ideally, data lines should cross power lines at right angles, and not run parallel like this. It works okay here because the bus is partly shielded, as is the cable tray, and there's about a foot spacing between them.
At the other end of this corridor is the wiring plant. Each floor has one of these, divided into data and voice lines. In theory, that is. In practice, you use whichever lines that end at convieniently located jacks. There is no difference electrically- it's all just AT&T 6-pair wire. It isn't really that great as phone wire, let alone for data.
Above the type-66 wiring blocks (also made for voice-only...) we have the hubs. This style hub was used because we don't have the space or any real need for nifty rack-mount stacked units. Which is too bad, because as is, it looks real nasty. Fribble is plugged into the right-most port of the left hub, with its patch wire running about 4 feet to a block point. Total wiring length to here is about 200 feet or so. I once had an exact length from a TDR cable tester, but I have since forgot it. It's longer than it really should be with such poor wire.
Each hub is plugged through a AUI-BNC tranceiver into a coax backbone. I don't really like using the coax at all, but it works well enough. I just wonder if fiber was ever considered for this installation.
Since I took these pictures, I've added a third hub and made my side of the panel much neater. New pics forthcoming.
After the data hits the coax point, I have little to do with it. The campus people (ITS/ACS) handle it. There are a couple routers upstream before it all gets switched into RPI's T3 line(s). It seems that no matter how much more bandwidth they get, it is consumed before they can brag about how much we have. Plus they use Sprint for T3 service, quite a gamble given the overall flakiness of Sprint's network.
To mount the hubs, we simply had to remove some signs that had hung on the wall:
Which is now a decoration in my office. ITS still does telephone wiring and much of other department's wiring. I won't offer my opinion on their policies at large, but they sure do a crappy job on their wiring.