Network Essay Example | Topics and Well Written Essays - 1000 words - 1

Network - Essay Example So, we use repeaters and hubs (as shown in Figure 1). Repeaters buffer the input signal and send the amplified version of the same signal to only the output port. Hubs are basically broadcasters (multiport repeaters). The signal is repeated to all ports other than the input port. Ethernet is a shared medium, so, all nodes use the same medium for transmission of data. When two nodes send data at the same instant, the data collides and its validity and integrity is compromised. Data has to be sent again. Although Ethernet uses CSMA/CD (Tanenbaum 2003) for collision yet there are still delays. So, networks are designed to avoid collisions while ensuring efficient utilization of bandwidth, providing good network throughput. In Figure 1, in case two nodes broadcast at the same time, collision occurs. Hubs/repeaters also limit the number of nodes that can be supported (see Table 1 (Technick n.d.)). So networks cannot expand beyond a limit. As at a time, the entire bandwidth can be utilized by only one node, so the overall throughput is limited. For avoiding collisions, the network traffic needs to be isolated. So the big networks are divided into smaller segments. These segments are connected together through bridges and switches. Bridges and switches (bridges with enhancements) are transparent intelligent devices that facilitate growth of LANs with the same underlying functionality. They can connect a node or a full Ethernet segment (with its own set of switches, hubs and repeaters) of even different LAN technologies on each of their ports (see Figure 2). They map the MAC addresses of nodes to each port. For each incoming frame the bridge/switch checks the destination MAC address. If the destination MAC lies on another port, only then it forwards, else it filters the frame thus keeping it within the segment it came from. The collision domain is separated. If there is a collision in one segment, the effect