On 11-Sep-2007, at 1514, Justin M. Streiner wrote:

Some of the local old-school Bell Atlantic/Verizon techs also did very clean work, but most of them took the early retirement packages that were offered 4-5 years ago.

This (the general subject of how to keep real-world cabinets tidy and do cabling in a sane way) seems like an excellent topic for a NANOG tutorial. I'd come, for sure :-) When I worked on the ISP side of a phone company in New Zealand in the early nineties the telco facilities techs did some beautiful work, particularly on some very large copper distribution frames (for strange regulatory reasons there was one very large class 5 switch at this telco to service local access customers all over Auckland, with result that almost the whole first floor of 49 Symonds Street was built out as an enormous CO). I once asked one of the telco guys to come and impart some cable management clue to us, but didn't get very far. The bemused response when we were both standing in front of the ISP racks was "but this is IT gear. IT gear is always messy." Joe

Does anyone know if any good resources on best-practices at this sort of thing? I'm pretty sure that others must've already figured out the trickier stuff that I've thought about. Most good cabling jobs require one thing- dedication.

If you are willing to put in the time and effort, you can do a good cabling job the first time. Think about how the cables will get used, what might change in the future, and then lay them out so as to minimize problems when things need to be moved or upgraded. Then again, sometimes it requires a whole lot more dedication. In our case the racks we inherited were installed wrong (no space between them for vertical cable management). Getting our cabling organized meant welding our own cable management brackets that we could bolt onto the front of the racks. I'll post some pictures when I get a chance. -Don

On Wed, Sep 12, 2007 at 08:36:45AM -0400, Joe Abley wrote:

...

This (the general subject of how to keep real-world cabinets tidy and do cabling in a sane way) seems like an excellent topic for a NANOG tutorial. I'd come, for sure :-)

This is a topic that I am quite interested in. I have no telco background, but got started in a shop on par with many of these photos. Around my current job, I'm the guy who is known for whining about crappy cabling jobs.

Does anyone know if any good resources on best-practices at this sort of thing? I'm pretty sure that others must've already figured out the trickier stuff that I've thought about.

For example - some of the posted pictures show the use of fiber ducts lifted above cable ladders. Why opt for such a two-level design instead of bundling fibers in flex-conduit and running the conduits adjacent on the ladder?

Design decisions for cabling will vary with the facility and actual intended uses. For example, an Internet Service Provider with significant telecom requirements may be designed quite differently than a hosting provider. Facilities where the design is not likely to change significantly are a good candidate for "tidy cabling" of the sort under discussion here, but where changes are expected to be common and frequent, there are other ways to make it look nice, without investing a ton of time just in time for next quarter's changes. The best thing you can do is to allow for what might seem to be excessive amounts of space for cable management, and then be prepared to spend TIME when installing equipment or making changes. The biggest thing that any serious cablemonkey will tell you (and I won't argue it!) is that the job takes TIME to do right. Remember that the time invested isn't being invested just to make it look good, but more importantly to make it easy to deal with when something goes wrong. Good cable guys deserve a lot of respect, for making it so easy to debug what's going on when something goes wrong. The design for your facility is best based on the unique situation present at your facility. ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net "We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.

Once upon a time, David Lesher <wb8foz@nrk.com> said:

If you find any pictures of NY.NET; Terry Kennedy made the above look sloppy. Many places ban cable ties due to the sharp ends;

The first thing people here learn is how to properly use flush-cut side snips to cut a zip-tie end. When done right, you don't get the sharp (hand slicing) ends. Of course, the local telco guys use zip-ties, but use their telco scissors to cut the end, leaving a sharp end. If it is near our stuff, we'll come behind them and trim the ends; otherwise, it is their fingers that'll get sliced next time. -- Chris Adams <cmadams@hiwaay.net> Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble.

If you find any pictures of NY.NET; Terry Kennedy made the above look sloppy. Many places ban cable ties due to the sharp ends; some allow 'em if tensioned by a pistol-grip installer.

The tie gun is a good solution, but quite frankly, you don't need one to do a good job with cable ties. This is mainly a training issue, and the training is substantially easier than training folks to use lacing cord. The rule doesn't need to be much more than "clean cut required, if you can't do a clean cut, then leave the tail on." Xcelite makes some fantastic tools, as anyone in this business should know, and they have a wide selection of full flush cutters that will work fine. There are some other manufacturers who make this sort of cutter, of course, but they're a bit tricky to find. The key thing is that people learn not to just use any old wire cutters to snip these. If you're really good, and the situation allows, you can use a knife or box cutter to trim ends as well.

Terry required lacing cord. You can guess his heritage.

That's mostly a pain to do. Looks nice, but hell to modify, and more time and effort to install initially.

As for horror stories, a certain ISP near here that started out in a video store had piles of Sportsters. The wall warts were lined up and glued dead-bug style to a number of long 1x3's; then #14 copper was run down each side, daisy-chain soldered to each plug blade. There was no attempt to insulate any of upright plugs...

ExecPC, here in Wisconsin, had a much more elegant solution. ExecPC BBS was the largest operating BBS in the world, with a large LAN net and a PC per dial-in line. They had built a room with a custom rack system built right in, where a motherboard, network, video, and modem card sat in a slot, making a vertical stack of maybe 8 nodes, and then a bunch of those horizontally, and then several rows of those. That was interesting all by itself, but then they got into the Internet biz early on. They had opted to go with USR Courier modems for the Internet stuff. Being relatively "cheap", they didn't want to go for any fancier rack mount stuff (== much more expensive). So they went shopping. They found an all metal literature rack at the local office supply store that had 120 slots (or maybe it was two 60 slot units). They took a wood board and mounted it vertically above the unit. This held a large commercial 120-to-24vac step-down transformer and a variac that was used to trim the AC voltage down to the 20VAC(?) needed by the Couriers. Down the backside, they ran a run of wide finger duct vertically. Inside this, they ran two thick copper bars that had been drilled and tapped 120 times by a local machine shop. When connected to the step-down transformer's output, this formed the power backbone. They had a guy snip the power cables off the Courier wall warts, and spade lug them, and screwed them in. Instant power for 120 modems. Slip a modem in each slot. Run phone wire up to one of five AllenTel AT125-SM's hanging on the back of the plywood, and there you have 5 25pr for inbound. Run serial cables up to one of four Portmaster PM2E-30's sitting on top of the racks, then network to a cheap Asante 10 megabit hub, and you're done. 5 x 25pr POTS in, power in, ethernet out, standalone 120 line dialin solution. Multiply solution by 10 and you get to the biggest collection of Courier modems I've ever seen. They continued to do this until the advent of X2, which required T1's to a Total Control chassis, at which point they started to migrate to rackmount gear (they had no space to go beyond 1200 analog Couriers anyways). ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net "We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.