difference straight through and crossover
Crossover cables use two different wiring standards: one end uses the T568A wiring standard, and the other end uses the T568B wiring standard. To determine if you have a straight-through or crossover cable, compare the Ethernet cables to see if the colors are wired in the same order on each end. For more information on Ethernet wiring standards, refer to the following FAQ: http://www.startech.com/faq/network_cables_a_vs_b_pinout.