Many network administrators are worried about the colors of the patch cables and assigning them to a certain function. For example, red patch cables could mean crossover or outside the firewall, where blue are servers or desktops, or purple connect to APs, etc. However, the actual labeling of cables, and wall jacks, get severely overlooked. Have you ever unplugged a cable from a switch or patch panel to test something and then when you went to plug it back in you couldn’t remember where it was supposed to go? This article is my recommendation for labeling cables.
A patch cable typically gets connected to a patch panel on one end and a device on the other. When the cable is labeled, the label needs to clearly indicate what it is connected to on both ends. Let’s say your patch panel is in rack 4.01 (row 4, rack 1) and the top of the patch panel (for multiple rack unit patch panels) is on U34. Then you are going to connect the cable to port 15 on that patch panel. Your description for the patch panel port should be R4.01/U34/P15. Now let’s say you are connecting it to a chassis based switch named Access1 on blade 6, port 29. Your description of the switchport connection should be A1/S6/P29, where A1 is the abbreviation for the switch, S is for slot, and P is for port. Both the description of the patch panel port and the switchport should be on each label at both ends of the cable. When you disconnect the cable on either side, you know exactly where to connect it back from the label and the label tells you where the other end goes. Labels be identical on both ends of every patch cable. You type it once and print it twice.
Patch panels should be label with what is on the other end. In a Data Center where you have infrastructure cabling going from one rack to another, the patch panels should be labeled with the rack and U of the other patch panel. If it is the same port for port, then you don’t have to label the individual ports. However, if one patch panel is split between two patch panels on the other end, then the ports on all three patch panels should be labeled. When it is clearly defined, then it avoids confusion and mistakes.
When the patch panel is used for drops to user workstations, then each patch panel port should be labeled with the unique ID of the drop on the floor. This should be done by your cabling vendor and part of their standard scope of work. In addition, your cabling vendor should provide you with a digital copy of your floor plan and the unique IDs on the drawing where they are located on the floor plan. This may cost you a little more for them to do this, but it’s worth it’s weight in virtual gold when you are trying to locate where that device is in the building.
The drop at the wall jacket, or biscuit, should be labeled too. This label should include the drop ID from the floor plan and the patch panel ID. The patch panel ID should be in the format of IDF identifier, rack, patch panel, and port. For example, let’s use IDF 02, rack 03, patch panel 34, and port 48. The label should look something like I02/R03/PP34/P48. That’s a lot to put on a label going into a small space, so if you have a standard format you can shorten it. A shorter version could be 02/03/34/48, or, non-zero filled, 2/3/34/48. I would encourage you to not drop the IDF or rack identifiers, because while you are told they will never expand or grow the site, it will happen. Develop a standard, stick with it, and be consistent.
For the floor plan drop ID, you should use something that will help you locate the drop on the floor. Something that includes room numbers is always good. Avoid labels that could easily change, like MARK-1 for Mark’s office. When you have both the drop ID and the patch panel port labeled on the jack, it will help reduce time to locate and troubleshoot workstation connectivity issues.
Labeling is only as good as you make it…keep up with it. Make a standard for your labeling, document that standard, and stick to it.