Skip to main content

The benefits of using repeaters / Full-duplex transmitting

The benefits of using repeaters 
4.1.8 This page will explain how a repeater can be used to extend the distance of a LAN.
The distance that a LAN can cover is limited due to attenuation. Attenuation means that the signal weakens as it travels through the network. The resistance in the cable or medium through which the signal travels causes the loss of signal strength. An Ethernet repeater is a physical layer device on the network that boosts or regenerates the signal on an Ethernet LAN. When a repeater is used to extend the distance of a LAN, a single network can cover a greater distance and more users can share that same network. However, the use of repeaters and hubs adds to problems associated with broadcasts and collisions. It also has a negative effect on the overall performance of the shared media LAN. 
The Interactive Media Activity will teach students about the Cisco 1503 Micro Hub.
The next page will discuss full-duplex technology.

Full-duplex transmitting 
4.1.9 This page will explain how full-duplex Ethernet allows the transmission of a packet and the reception of a different packet at the same time. This simultaneous transmission and reception requires the use of two pairs of wires in the cable and a switched connection between each node. This connection is considered point-to-point and is collision free. Because both nodes can transmit and receive at the same time, there are no negotiations for bandwidth. Full-duplex Ethernet can use a cable infrastructure already in place, as long as the medium meets the minimum Ethernet standards.
To transmit and receive simultaneously, a dedicated switch port is required for each node. Full-duplex connections can use 10BASE-T, 100BASE-TX, or 100BASE-FX media to create point-to-point connections. The NICs on all connected devices must have full-duplex capabilities.
The full-duplex Ethernet switch takes advantage of the two pairs of wires in the cable and creates a direct connection between the transmit (TX) at one end of the circuit and the receive (RX) at the other end. With the two stations connected in this manner a collision free environment is created as the transmission and receipt of data occurs on separate non-competitive circuits.
Ethernet can usually only use 50 to 60 percent of the available 10 Mbps of bandwidth because of collisions and latency. Full-duplex Ethernet offers 100 percent of the bandwidth in both directions. This produces a potential 20 Mbps throughput, which results from 10 Mbps TX and 10 Mbps RX.
The Interactive Media Activity will help students learn the different characteristics of two full-duplex Ethernet standards.
This page concludes this lesson. The next lesson will introduce LAN switching. The first page describes LAN segmentation.

Comments

Post a Comment

Popular posts from this blog

OSI layers / Peer-to-peer communications / TCP/IP model

OSI layers 2.3.4 This page discusses the seven layers of the OSI model. The OSI reference model is a framework that is used to understand how information travels throughout a network. The OSI reference model explains how packets travel through the various layers to another device on a network, even if the sender and destination have different types of network media. In the OSI reference model, there are seven numbered layers, each of which illustrates a particular network function. - Dividing the network into seven layers provides the following advantages: • It breaks network communication into smaller, more manageable parts. • It standardizes network components to allow multiple vendor development and support. • It allows different types of network hardware and software to communicate with each other. • It prevents changes in one layer from affecting other layers. • It divides network communication into smaller parts to make learning it easier to understand. In the foll...
Post a Comment
Read more

Advantages and disadvantages of link-state routing

Advantages and disadvantages of link-state routing 2.1.5  This page lists the advantages and disadvantages of link-state routing protocols. The following are advantages of link-state routing protocols:  Link-state protocols use cost metrics to choose paths through the network. The cost metric reflects the capacity of the links on those paths. Link-state protocols use triggered updates and LSA floods to immediately report changes in the network topology to all routers in the network. This leads to fast convergence times. Each router has a complete and synchronized picture of the network. Therefore, it is very difficult for routing loops to occur. Routers use the latest information to make the best routing decisions. The link-state database sizes can be minimized with careful network design. This leads to smaller Dijkstra calculations and faster convergence. Every router, at the very least, maps the topology of it...
Post a Comment
Read more

Symmetric and asymmetric switching / Memory buffering

Symmetric and asymmetric switching   4.2.8  This page will explain the difference between symmetric and asymmetric switching. LAN switching may be classified as symmetric or asymmetric based on the way in which bandwidth is allocated to the switch ports. A symmetric switch provides switched connections between ports with the same bandwidth. An asymmetric LAN switch provides switched connections between ports of unlike bandwidth, such as a combination of 10-Mbps and 100-Mbps ports. Asymmetric switching enables more bandwidth to be dedicated to the server switch port in order to prevent a bottleneck. This allows smoother traffic flows where multiple clients are communicating with a server at the same time. Memory buffering is required on an asymmetric switch. The use of buffers keeps the frames contiguous between different data rate ports. The next page will discuss memory buffers. Memory buffering   4.2.9  This page will explain what a memory buffer is...
Post a Comment
Read more