1.3 ETHERNET IN MODERN NETWORKING
1.3 ETHERNET
Continuing the top-down approach of the preceding two sections, the next three sections focus on key network transmission technologies of Ethernet, Wi-Fi, and 4G/5G cellular networks. Each of these technologies has evolved to support very high data rates. These data rates support the many multimedia applications required by enterprises and consumers and, at the same time, place great demands on network switching equipment and network management facilities. A full discussion of these network technologies is beyond the scope of this book. Here, we provide a brief survey.
Ethernet
The commercial name for a wired local-area network technology. It involves the use of a shared physical medium, a medium access control protocol, and transmission of data in packets. Standards for Ethernet products are defined by the IEEE 802.3 committee.
This section begins with discussion of Ethernet applications, and then looks at standards and performance.
Applications of Ethernet
Ethernet is the predominant wired networking technology, used in homes, offices, data centers, enterprises, and WANs. As Ethernet has evolved to support data rates up to 100 Gbps and distances from a few meters to tens of kilometers, it has become essential for supporting personal computers, workstations, servers, and massive data storage devices in organizations large and small.
Ethernet in the Home
Ethernet has long been used in the home to create a local network of computers with access to the Internet via a broadband modem/router. With the increasing availability of high-speed, low-cost Wi-Fi on computers, tablets, smartphones, modem/routers, and other devices, home reliance on Ethernet has declined. Nevertheless almost all home networking setups include some use of Ethernet. Two recent extensions of Ethernet technology have enhanced and broadened the use of Ethernet in the home: powerline carrier (PLC) and Power over Ethernet (PoE). Powerline modems take advantage of existing power lines and use the power wire as a communication channel to transmit Ethernet packets on top of the power signal. This makes it easy to include Ethernet-capable devices throughout the home into the Ethernet network. PoE acts in a complementary fashion, distributing power over the Ethernet data cable. PoE uses the existing Ethernet cables to distribute power to devices on the network, thus simplifying the wiring for devices such as computers and televisions. With all of these Ethernet options, Ethernet will retain a strong presence in home networking, complementing the advantages of Wi-Fi.
Ethernet in the Office
Ethernet has also long been the dominant network technology for wired local-area networks (LANs) in the office environment. Early on there were some competitors, such as IBM’s Token Ring LAN and the Fiber Distributed Data Interface (FDDI), but the simplicity, performance, and wide availability of Ethernet hardware eventually made Ethernet the winner. Today, as with home networks, the wired Ethernet technology exists side by side with the wireless Wi-Fi technology. Much of the traffic in a typical office environment now travels on Wi-Fi, particularly to support mobile devices. Ethernet retains its popularity because it can support many devices at high speeds, is not subject to interference, and provides a security advantage because it is resistant to eavesdropping. Therefore, a combination of Ethernet and Wi-Fi is the most common architecture. Figure 1.4 provides a simplified example of an enterprise LAN architecture. The LAN connects to the Internet/WANs via a firewall. A hierarchical arrangement of routers and switches provides the interconnection of servers, fixed user devices, and wireless devices. Typically, wireless devices are only attached at the edge or bottom of the hierarchical architecture; the rest of the campus infrastructure is all Ethernet. There may also be an IP telephony server that provides call control functions (voice switching) for the telephony operations in an enterprise network, with connectivity to the public switched telephone network (PTSN).
FIGURE 1.4 A Basic Enterprise LAN Architecture
Ethernet in the Enterprise
A tremendous advantage of Ethernet is that it is possible to scale the network, both in terms of distance and data rate, with the same Ethernet protocol and associated quality of service (QoS) and security standards. An enterprise can easily extend an Ethernet network among a number of buildings on the same campus or even some distance apart, with links ranging from 10 Mbps to 100 Gbps, using a mixture of cable types and Ethernet hardware. Because all the hardware and communications software conform to the same standard, it is easy to mix different speeds and different vendor equipment. The same protocol is used for intensive high-speed interconnections of data servers in a single room, workstations and servers distributed throughout the building, and links to Ethernet networks in other buildings up to 100 km away.
Ethernet in the Data Center
As in other areas, Ethernet has come to dominate in the data center, where very high data rates are needed to handle massive volumes of data among networked servers and storage units. Historically, data centers have employed various technologies to support high-volume, short-distance needs, including InfiniBand and Fiber Channel. But now that Ethernet can scale up to 100 Gbps, with 400 Gbps on the horizon, the case for a unified protocol approach throughout the enterprise is compelling.
Two features of the new Ethernet approach are noteworthy. For co-located servers and storage units, highspeed Ethernet fiber links and switches provided the needed networking infrastructure. Another important version of Ethernet is known as backplane Ethernet. Backplane Ethernet runs over copper jumper cables that can provide up to 100 Gbps over very short distances. This technology is ideal for blade servers, in which multiple server modules are housed in a single chassis.
blade server
A server architecture that houses multiple server modules (blades) in a single chassis. It is widely used in data centers to save space and improve system management. Either self-standing or rack mounted, the chassis provides the power supply, and each blade has its own CPU, memory, and hard disk.
Ethernet for Wide-Area Networking
Until fairly recently, Ethernet was not a significant factor in wide-area networking. But gradually, more telecommunications and network providers have switched to Ethernet from alternative schemes to support wide-area access (also referred to as first mile or last mile). Ethernet is supplanting a variety of other widearea options, such as dedicated T1 lines, synchronous digital hierarchy (SDH) lines, and Asynchronous Transfer Mode (ATM). When used in this fashion, the term carrier Ethernet is applied. The term metro Ethernet, or metropolitan-area network (MAN) Ethernet, is also used. Ethernet has the advantage that it seamlessly fits into the enterprise network for which it provides wide-area access. But a more important advantage is that carrier Ethernet provides much more flexibility in terms of the data rate capacity that is used, compared to traditional wide-area alternatives.
Carrier Ethernet is one of the fastest-growing Ethernet technologies, destined to become the dominant means by which enterprises access wide-area networking and Internet facilities.
Standards
Within the IEEE 802 LAN standards committee, the 802.3 group is responsible for issuing standards for LANs that are referred to commercially as Ethernet. Complementary to the efforts of the 802.3 committee, the industry consortium known as The Ethernet Alliance supports and originates activities that span from incubation of new Ethernet technologies to interoperability testing to demonstrations to education.
IEEE 802
A committee of the Institute of Electrical and Electronics Engineers (IEEE) responsible for developing standards for wireless LANs.
Ethernet Data Rates
Currently, Ethernet systems are available at speeds up to 100 Gbps. Here’s a brief chronology.
1983: 10 Mbps (megabit per second, million bits per second)
1995: 100 Mbps
1998: 1 Gbps (gigabits per second, billion bits per second)
2003: 10 Gbps
2010: 40 Gbps and 100 Gbps
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Continuing the top-down approach of the preceding two sections, the next three sections focus on key network transmission technologies of Ethernet, Wi-Fi, and 4G/5G cellular networks. Each of these technologies has evolved to support very high data rates. These data rates support the many multimedia applications required by enterprises and consumers and, at the same time, place great demands on network switching equipment and network management facilities. A full discussion of these network technologies is beyond the scope of this book. Here, we provide a brief survey.
Ethernet
The commercial name for a wired local-area network technology. It involves the use of a shared physical medium, a medium access control protocol, and transmission of data in packets. Standards for Ethernet products are defined by the IEEE 802.3 committee.
This section begins with discussion of Ethernet applications, and then looks at standards and performance.
Applications of Ethernet
Ethernet is the predominant wired networking technology, used in homes, offices, data centers, enterprises, and WANs. As Ethernet has evolved to support data rates up to 100 Gbps and distances from a few meters to tens of kilometers, it has become essential for supporting personal computers, workstations, servers, and massive data storage devices in organizations large and small.
Ethernet in the Home
Ethernet has long been used in the home to create a local network of computers with access to the Internet via a broadband modem/router. With the increasing availability of high-speed, low-cost Wi-Fi on computers, tablets, smartphones, modem/routers, and other devices, home reliance on Ethernet has declined. Nevertheless almost all home networking setups include some use of Ethernet. Two recent extensions of Ethernet technology have enhanced and broadened the use of Ethernet in the home: powerline carrier (PLC) and Power over Ethernet (PoE). Powerline modems take advantage of existing power lines and use the power wire as a communication channel to transmit Ethernet packets on top of the power signal. This makes it easy to include Ethernet-capable devices throughout the home into the Ethernet network. PoE acts in a complementary fashion, distributing power over the Ethernet data cable. PoE uses the existing Ethernet cables to distribute power to devices on the network, thus simplifying the wiring for devices such as computers and televisions. With all of these Ethernet options, Ethernet will retain a strong presence in home networking, complementing the advantages of Wi-Fi.
Ethernet in the Office
Ethernet has also long been the dominant network technology for wired local-area networks (LANs) in the office environment. Early on there were some competitors, such as IBM’s Token Ring LAN and the Fiber Distributed Data Interface (FDDI), but the simplicity, performance, and wide availability of Ethernet hardware eventually made Ethernet the winner. Today, as with home networks, the wired Ethernet technology exists side by side with the wireless Wi-Fi technology. Much of the traffic in a typical office environment now travels on Wi-Fi, particularly to support mobile devices. Ethernet retains its popularity because it can support many devices at high speeds, is not subject to interference, and provides a security advantage because it is resistant to eavesdropping. Therefore, a combination of Ethernet and Wi-Fi is the most common architecture. Figure 1.4 provides a simplified example of an enterprise LAN architecture. The LAN connects to the Internet/WANs via a firewall. A hierarchical arrangement of routers and switches provides the interconnection of servers, fixed user devices, and wireless devices. Typically, wireless devices are only attached at the edge or bottom of the hierarchical architecture; the rest of the campus infrastructure is all Ethernet. There may also be an IP telephony server that provides call control functions (voice switching) for the telephony operations in an enterprise network, with connectivity to the public switched telephone network (PTSN).
FIGURE 1.4 A Basic Enterprise LAN Architecture
Ethernet in the Enterprise
A tremendous advantage of Ethernet is that it is possible to scale the network, both in terms of distance and data rate, with the same Ethernet protocol and associated quality of service (QoS) and security standards. An enterprise can easily extend an Ethernet network among a number of buildings on the same campus or even some distance apart, with links ranging from 10 Mbps to 100 Gbps, using a mixture of cable types and Ethernet hardware. Because all the hardware and communications software conform to the same standard, it is easy to mix different speeds and different vendor equipment. The same protocol is used for intensive high-speed interconnections of data servers in a single room, workstations and servers distributed throughout the building, and links to Ethernet networks in other buildings up to 100 km away.
Ethernet in the Data Center
As in other areas, Ethernet has come to dominate in the data center, where very high data rates are needed to handle massive volumes of data among networked servers and storage units. Historically, data centers have employed various technologies to support high-volume, short-distance needs, including InfiniBand and Fiber Channel. But now that Ethernet can scale up to 100 Gbps, with 400 Gbps on the horizon, the case for a unified protocol approach throughout the enterprise is compelling.
Two features of the new Ethernet approach are noteworthy. For co-located servers and storage units, highspeed Ethernet fiber links and switches provided the needed networking infrastructure. Another important version of Ethernet is known as backplane Ethernet. Backplane Ethernet runs over copper jumper cables that can provide up to 100 Gbps over very short distances. This technology is ideal for blade servers, in which multiple server modules are housed in a single chassis.
blade server
A server architecture that houses multiple server modules (blades) in a single chassis. It is widely used in data centers to save space and improve system management. Either self-standing or rack mounted, the chassis provides the power supply, and each blade has its own CPU, memory, and hard disk.
Ethernet for Wide-Area Networking
Until fairly recently, Ethernet was not a significant factor in wide-area networking. But gradually, more telecommunications and network providers have switched to Ethernet from alternative schemes to support wide-area access (also referred to as first mile or last mile). Ethernet is supplanting a variety of other widearea options, such as dedicated T1 lines, synchronous digital hierarchy (SDH) lines, and Asynchronous Transfer Mode (ATM). When used in this fashion, the term carrier Ethernet is applied. The term metro Ethernet, or metropolitan-area network (MAN) Ethernet, is also used. Ethernet has the advantage that it seamlessly fits into the enterprise network for which it provides wide-area access. But a more important advantage is that carrier Ethernet provides much more flexibility in terms of the data rate capacity that is used, compared to traditional wide-area alternatives.
Carrier Ethernet is one of the fastest-growing Ethernet technologies, destined to become the dominant means by which enterprises access wide-area networking and Internet facilities.
Standards
Within the IEEE 802 LAN standards committee, the 802.3 group is responsible for issuing standards for LANs that are referred to commercially as Ethernet. Complementary to the efforts of the 802.3 committee, the industry consortium known as The Ethernet Alliance supports and originates activities that span from incubation of new Ethernet technologies to interoperability testing to demonstrations to education.
IEEE 802
A committee of the Institute of Electrical and Electronics Engineers (IEEE) responsible for developing standards for wireless LANs.
Ethernet Data Rates
Currently, Ethernet systems are available at speeds up to 100 Gbps. Here’s a brief chronology.
1983: 10 Mbps (megabit per second, million bits per second)
1995: 100 Mbps
1998: 1 Gbps (gigabits per second, billion bits per second)
2003: 10 Gbps
2010: 40 Gbps and 100 Gbps
Modern Computer Network Theory Playlist
Modern Computer Network Practical Playlist
#Subscribe the Channel Link :-
IF any Query or Doubt DM on #Instagram :-
#Bansode_Tech_Solution
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