Straight-Through CablesA straight-through cable is typically used in the following situations:
Use a straight-through cable when:
- Connecting a router to a hub
- Connecting a computer to a swtich
- Connecting a LAN port to a switch, hub, or computer
Note that some devices such as routers will have advanced circuitry, which enables them to use both crossover and straight-through cables. In general, however, straight-through cables will not connect a computer and router because they are not “unlike devices.”
Crossover Cables
Crossover cables are very similar to straight-through cables, except that they have pairs of wires that crisscross. This allows for two devices to communicate at the same time. Unlike straight-through cables, we use crossover cables to connect like devices.Use a crossover cable when:
- Connecting a computer to a router
- Connecting a computer to a computer
- Connecting a router to a router
- Connecting a switch to a switch
- Connecting a hub to a hub
Rollover Cables
Rollover cables essentially have one end of the cable wired exactly opposite from the other. This essentially "rolls over" the wires usually connect a device to a router or switch' s console port. This allows a programmer to make a connection to the router or switch, and program it as needed. It used to connect a computer terminal to a router's console port. This cable is typically flat (and has a light blue color) to help distinguish it from other types of network cabling. It gets the name rollover because the prinouts on one end are reversed from the other, as if the wire had been rolled over and you were viewing it from the other side. This rollover cable is more commonly known as the Yost cable or more appropriately the "Yost Serial Device Wiring Standard".
Networking DevicesNetworking devices are classified into two:-
1. DCE :- Data Communication Equipment. Ex: Hub, Switch
2. DTE :- Data Termination Equipment. Ex: PC, Router