Thought Lab: Why Cable Management Is Important

[deanwebb]

You need no network equipment for this lab, or even much knowledge of networking.

1. Imagine 10 switches, 2 routers, 1 firewall, and 200 different hosts, all attached with ethernet cables.
2. Imagine now that you have to move all the network gear from one room to another.
3. Imagine also that certain ports on the switches are provisioned differently than other ports. That is to say, some of them are set up to handle switch to switch communication, ports to connect to the routers, and special ports to handle communication to hosts with multiple network cards for faster communication.
4. Imagine now that all the cables are the same color and the same length. Total standardization.
5. How will you be able to figure out which cables go where?

6. Assuming you said, "label them!" in answer to the above, would you label one end or both ends? What should be on the labels? Should you use a label maker or just masking tape that you wrote on with a Sharpie?

7. If you said tape with Sharpie for #6, go back and try again. Once you've accepted that you need a label maker, what kind is best to use? Use a search to find "best network cable label solution". Which ones are totally awesome? Which ones will your company likely pay for? Will you be able to live with yourself if you have to use the cheaper option?

8. If you thought labeling only one end of the cable was the right way to go, imagine all the cables are plugged in on their labeled ends. Where do they unlabled ends go? Are you sure?  That's right, label both ends.

9. When should you label both ends of the cable, when they're connected, or when the cable's on the ground in a big pile with the other cables?

10. How long do you think it's going to take to label both ends of each cable? Is this something that should already be done by now?

11. Would it help to also go into the switch configurations and provide descriptive comments on what each switchport is connected to? Would it also help to have that information printed out and stored somewhere for reference? Would it also also help to keep that reference up to date?

12. What about the patch panel? Do you think it would be a good idea to have labels there, as well?

13. How do you figure out which patch panel number goes with which wall outlet in an office? Search for "network toner probe". Read up on what those guys can do, maybe watch a video of how to use one. Does that information help answer this question?

14. OK, so let us now assume that, in preparation for the big move and for general nice-to-have considerations, everything in the network is labeled properly. You could toss all the cables on the floor in a big mess and put them back together, no problem, because they are all labeled on both ends. Now it's time to imagine all the cables plugged in and just hanging there, like abandoned spider webs. Is that what you want your network closet to look like?

15. If you answered "yes" to #14, get out of here.  Go be a sysadmin or a database developer. If, on the other hand, you want those cables to be nice and tidy, read on.

16. Some racks have channels on the sides where cables can be stored. Others do not. For those, and for when the cables have to extend from one rack to another or from a rack to a patch panel, there are zipties and velcro straps. Which is easier to work with, a fixed ziptie or an adjustable velcro strap?

17. If a cable is determined to be defective, you would have to remove it from the bundle it is strapped up in. How many velcro straps would you want to have to undo and redo in order to remove that cable and put a new one in its place? The correct answer, of course, is "as few as I can get away with".

18. Imagine now that you've done the big move, all the cables are where they should be and all the cables are neatly arranged in pleasingly ordered channels and bundles. Those that gaze upon them marvel at your organizational prowess. Enjoy this moment.

19. Now imagine that the firm adds another switch with another 20 hosts. Will you label all of those cables, as well? Will you incorporate all those cables into appropriate channels and bundles? Will you update your documentation?

20. If you said "yes" to all questions in #19, congratulations, you're ready to do this in real life. If you did not, depart hence and consider diverting your IT interests towards kernel debugging or something like that. But if you want to keep it clean and well-documented, congratulations! You are ready to be a network admin for a small or medium sized company, provided you also learn about actual networking! Now we celebrate!

[jackluter]

It's a brief explanation in routing the cables from different racks and I am very confused  to know about patch panels that makes me difficult to figure out. Overall the process is well explained.

[deanwebb]

It's a brief explanation in routing the cables from different racks and I am very confused  to know about patch panels that makes me difficult to figure out. Overall the process is well explained.

Patch panels are tricky, since they are where the LAN meets old-style telephone panels. I find that using toners to discover what's at the other end of a line are very helpful in creating labels and maps correlating the patch panel to a physical location in the office. Different countries can potentially have different wiring schemes. I've been in Russia, for example, where their telephony system developed independently from US systems, and making sense of those is not an easy thing to do.