Let us go through various LAN technologies in brief:
Ethernet
- Ethernet is one of the most extensively used LAN technologies. In the year 1970, Bob Metcalfe and D.R. Boggs developed this technology. In 1980, IEEE 802.3 standardized it.
- Ethernet is a media sharing protocol. Data collision is very likely in a network that employs shared media.
- To detect collisions, Ethernet employs Carrier Sense Multi Access/Collision Detection (CSMA/CD) technology.
- When an Ethernet host encounters a collision, all of the hosts roll back, wait for a random amount of time, and then re-transmit the data.
- A network interface card having a 48-bit MAC address is known as an Ethernet connector. This aids other Ethernet devices in recognizing and communicating with faraway Ethernet devices.
- The 10BASE-T protocol is used in traditional Ethernet. BASE stands for base-band, while T refers for thick Ethernet. The number 10 represents 10MBPS speed. 10BASE-T Ethernet uses coaxial cable or Cat-5 twisted pair cable with RJ-5 connector to provide transmission speeds of up to 10MBPS.
- Ethernet has a star architecture with segments up to 100 metres in length. In a star configuration, all devices are connected to a hub/switch.
Fast-Ethernet
- Ethernet is extended as Fast-Ethernet to address the requirement for fast growing software and hardware advancements. It works with UTP, Optical Fiber, and wireless connections.
- It has a speed of up to 100 MBPS. In IEEE 803.2, this standard is known as 100BASE-T, and it uses Cat-5 twisted pair cable. For wired media sharing among Ethernet hosts, it uses the CSMA/CD approach, while for wireless Ethernet LAN, it uses the CSMA/CA (CA stands for Collision Avoidance) technique.
- Fast Ethernet over fiber is described by the 100BASE-FX standard, which allows for speeds of up to 100 MBPS. Over multi-mode fibers, Ethernet over fiber can be extended up to 100 metres in half-duplex mode and up to 2000 metres in full-duplex mode.
Giga-Ethernet
- Fast-Ethernet, which was first released in 1995, could only maintain its high-speed status for three years before Giga-Ethernet was developed.
- Giga-Ethernet offers speeds of up to 1000 megabits per second.
- IEEE802.3ab specifies the use of Cat-5, Cat-5e, and Cat-6 cables for Gigabit Ethernet over UTP. Gigabit Ethernet over Fiber is defined by IEEE802.3ah.
Virtual LAN
- Ethernet is used in LANs, and Ethernet works on shared media. In Ethernet, shared media creates a single Broadcast domain and a single Collision domain.
- Switches have solved the problem of a single collision domain, and each device connected to a switch now operates in its own collision domain.
- Switches, on the other hand, are unable to divide a network into different Broadcast domains.
- A virtual LAN divides a single Broadcast domain into multiple Broadcast domains. A host in one VLAN cannot communicate with a host in another VLAN. All hosts are automatically assigned to the same VLAN.
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Virtual LAN |
- Distinct VLANs are displayed in different color codes in this figure. Even if they are linked to the same Switch, hosts in one VLAN cannot see or communicate with hosts in other VLANs.
- VLAN is a Layer-2 technology that works in conjunction with Ethernet. A Layer-3 device, such as a Router, is required to transport traffic between two separate VLANs.
