Twisted Pair Ethernet

This type of Ethernet wiring is known as Third Generation of Ethernet wiring.This generation is completely differ from its previous two generation that are thick and thin Ethernet because it does not use a coaxial cable.This generation Ethernet typically known as twisted pair Ethernet or TP Ethernet and its first version was formally known as 10BaseT.The wiring for Fast Ethernet is known as 100BaseT,and wiring for Gigabit Ethernet is known as 1000BaseT.Instead of shared medium,the new technology extends the idea used with connection multiplexing in which an electronic device serves as the center of the network.
The basic electronic device is known as an Ethernet Hub.Like the other wiring schemes,twisted pair requires each computer to have a network interface card and a direct connection from NIC to the network.The connection uses unshielded twisted pair wiring with RJ-45 connectors which are the largest versions of the modular connectors used with the telephones.The connector on one end of a twisted pair cable plugs into the network interface on a computer and the connector on the other end plugs into the hub.
Thus,each computer has a dedicated connection to the hub device.Electronic components in hub emulate a physical cable,making the entire system operate like a conventional Ethernet.For ex:A computer attached to a hub must have a physical Ethernet Address that means each computer must use the CSMA/CD to access the network and the standard Ethernet Frame Format.In fact,software does not distinguish between thick Ethernet,thin Ethernet and twisted pair Ethernet because the network interface handles the details and hides any differences.

Combining Switches and Hubs

From the last post it is clear that switching provides higher aggregate data rates in comparison to a hub,but the main drawback that occurred with the switched networks is the higher cost in comparison to hub.To overcome all these problems network administrator choose a compromise between the hub and the switched networks that means instead of connecting one computer to each port on a switch,the administrator connects the hub to each of the port of the switch and then connect each computer to one of the hubs.This result is very much closer to the conventional bridged LAN where each hub appears to be a single LAN segment, and the switch makes it appear that bridges connect all segments.The system also performs like a conventional bridged LAN where a computer must share a bandwidth with other computers connected to the same hub,communication can occur in parallel between a pair of computers attached to one hub and a pair of computers attached to another.

Concept of Switching

In general,a network technology is called switched if the hardware includes an electronic device that connects to one or more computers and allows them to send and receive data from each other.More specifically,a switched LAN consisted of a single electronic device that transfers frames among many computers.As all we know that a switch resembles a hub,like a hub, a switch consists of a single box with multiple ports that each attach to a single computer.The main difference between a switch and a hub arises from the way the devices operates,a hub simulates a single shared medium while in the case of a switch it simulates a bridged LAN with one computer per segment.

If we talk about the chief advantage of using a switched LAN instead of a hub then the reason is same as that of using bridged LAN instead of a single segment.In the case of a hub a single segment is shared by all computers,that means at most two computers can communicate through hub at a time.Thus the maximum possible throughput of a hub system is R,the rate at which single computer can send data across a LAN segment.In the case of a switched LAN,each computer has a simulated LAN segment to itself that means the segment is busy only when a frame is being transferred to or from the computer.As a result,as many as one half of the computers connected to a switch can send the data at the same time(if they send to one of the computers that is not busy in sending).Thus,in this case the maximum throughput of a switch is RN/2 where R is the rate at which data transmits,and N is total number of computers that are connected to the switch.

Repeater Vs Switch Vs Hub

Hello friends this is my post and i this post i am going to give you a brief description and difference between various networking devices.

As all we know various types of devices like repeaters,hub, routers, switch are used very frequently in the setup of any computer network.Here in this post we see all these devices one by one.

Repeater: A repeater is an electronic device that is used to receive a signal and after receiving, it transmit signal to the higher level so that it can move to long distance without any destruction in its value.In other words we can also say that repeater is a device that is designed to overcome signal attenuation means to recover signal degradation.All repeaters has two ports one for receiving the signal and other for its transmission. Repeaters can be used for carrying electrical signals in the form of copper wire or to carry light in the form of fiber optics.It is a layer 1 device that means Physical layer device.

Hub: In simple words we can say that a hub is a multi port repeater.It means it allows multiple machines to connect to the same network, by broadcasting traffic to all of its ports.The most practical implication of this is that only one device can send data at a time, otherwise a collision occurs. Hubs implement a collision detection multiple access method to detect when two machines attempt to send data at the same time. A hub supports broadcasting of any signal.It is also layer 1 device.

Switch:In general switch is very much different from the repeater and the hub , both of them works on IP address while the switch works on the MAC address. A switch works by keeping track of which MAC addresses are attached to each port. It inspects traffic and only sends it to the port that the destination device is on (based on the destination MAC address). A switch had a finite amount of memory in which it can store MAC addresses, smaller switches such as ones intended for desktop use have less memory then larger ones that may form part of an enterprise networks backbone. When a switches memory becomes full of active MAC addresses it will often revert to functioning like a hub and broadcast traffic to all ports.A switch is a layer 2 device(Data link Layer).