IBM C2T

C2T (stands for Cable Chaining Technology) is an IBM technology for KVM (keyboard, video, mouse) chaining. Built into some of the IBM's xSeries models, allows to daisy-chain up to forty-two servers in a single rack. Each server that uses C2T ships with the daisy chaining cable that is used to connect it to the next server in the rack. The final server in the stack is connected to the KVM switch using breakout cable, which can also be used to connect directly into a keyboard, video monitor and mouse (no need for a KVM switch).A controversial fact is, that this breakout cable is very expensive to purchase, running around 60 USD used or new on Ebay, although the cable does not contain any active electronic devices that would justify this high price.

C2T works thanks to a chip on the planar that emulates a KVM switch. To take control of a certain xSeries server in the rack, user needs to press Num Lock twice, "nn" (where "nn" is the number of the server) and then press Enter, or could also manually press the button on the front of the desired xSeries server. This innovative technology allows to reduce the cable clutter in the rack and saves money since it does not require the KVM switch or cables.