EIA/TIA

EIA/TIA:- Electronic Industries Alliance/Telecom Industries Association. Basically provide the color combination mechanism  for STP/UDP cable in order to provide better/ faster communication.

Notice that the pin-outs stay the same, and the only difference is in the color coding of the wiring.

Type of Cable ;- commonly used cable type are 

• Cross over cable :- for different layer devices i.e Router to switch
• Straight through cable :- for same level devices i.e switch to switch
• Roll over cable:- console cable (for 1st use of device)

Cross over cable is used to connect device of different  level such as Route is layer 3 device and switch is layer 2 device and hence could be connected with cross over cable. a very general idea behind is that the end of sending port  has to connected with receiving port of other device

Fig- 2
pin out for cross over cable and straight through cable 

So for bilateral communication between the devices sending pin (1) of the device-1 has to be connected with the receiving pin (3) of other device  that is how as shown in the picture-1 wire from one end of  pin 1 has to be connected with pin 3 and hence pin 2 form port 6.  

                                                        Pin Layout or cross over cable

                                               one end         connected with       other end

                                                    1------------------------->---------------------3

                                                    2-------------------------->--------------------6

                                                    3-------------------------->--------------------1

                                                    4-------------------------->--------------------4

                                                    5-------------------------->--------------------5

                                                    6-------------------------->--------------------2

                                                    7-------------------------->--------------------7

                                                    8-------------------------->--------------------8

Note :- only thing to remember is that device send data from pin 1 & 2 and Receive data for pin 3 & 6. 

mnemonics for learning the ping out wiring group is like 

oogbbgbb and ggobbobb read the single word at a time which is nothing but the single word of each wire and have to add white in a alternate fashion as  shown in pic-1

Straight through cable :- it is the simplest type of wire grouping and no special intelligence  require, each pin-out connected with the respective pin out i.e 1-1, 2-2, 3-3, 4-4, 5-5, 6-6 7-7, 8-8 as shown in fig -2

Roll over Cable:- is a type of null-modem cable also known as the console cable or yost cable that is often used to connect a computer terminal to a router's console port, its pin out have opposite Pin assignments on each end of the cable or in other words it is "rolled over"
its pin out like 1-8, 2-7, 3-6, 4-5, 5-4,6-3, 7-2, 8-1

pin out of Roll over cable

                                                             1-------------8
                                                             2-------------7
                                                             3-------------6
                                                             4-------------5
                                                             5-------------4
                                                             6-------------3
                                                             7-------------2
                                                             8-------------1