Ethernet has been around for over 30 years and has no serious competitors in
sight, so it is likely to be around for many years to come. Few CPU architectures,
operating systems, or programming languages have been king of the mountain for
three decades going on strong. Clearly, Ethernet did something right. What?
Probably the main reason for its longevity is that Ethernet is simple and flexible. In practice, simple translates into reliable, cheap, and easy to maintain. Once the hub and switch architecture was adopted, failures became extremely rare. People hesitate to replace something that works perfectly all the time, especially when they know that an awful lot of things in the computer industry work very poorly, so that many so-called ‘‘upgrades’’ are worse than what they replaced.
Simple also translates into cheap. Twisted-pair wiring is relatively inexpensive as are the hardware components. They may start out expensive when there is a transition, for example, new gigabit Ethernet NICs or switches, but they are merely additions to a well established network (not a replacement of it) and the prices fall quickly as the sales volume picks up.
Ethernet is easy to maintain. There is no software to install (other than the drivers) and not much in the way of configuration tables to manage (and get wrong). Also, adding new hosts is as simple as just plugging them in.
Another point is that Ethernet interworks easily with TCP/IP, which has become dominant. IP is a connectionless protocol, so it fits perfectly with Ethernet, which is also connectionless. IP fits much less well with connection-oriented alternatives such as ATM. This mismatch definitely hurt ATM’s chances.
Lastly, and perhaps most importantly, Ethernet has been able to evolve in certain crucial ways. Speeds have gone up by several orders of magnitude and hubs and switches have been introduced, but these changes have not required changing the software and have often allowed the existing cabling to be reused for a time. When a network salesman shows up at a large installation and says ‘‘I have this fantastic new network for you. All you have to do is throw out all your hardware and rewrite all your software,’’ he has a problem.
Many alternative technologies that you have probably not even heard of were faster than Ethernet when they were introduced. As well as ATM, this list includes FDDI (Fiber Distributed Data Interface) and Fibre Channel,† two ringbased optical LANs. Both were incompatible with Ethernet. Neither one made it. They were too complicated, which led to complex chips and high prices. The lesson that should have been learned here was KISS (Keep It Simple, Stupid). Eventually, Ethernet caught up with them in terms of speed, often by borrowing some of their technology, for example, the 4B/5B coding from FDDI and the 8B/10B coding from Fibre Channel. Then they had no advantages left and quietly died off or fell into specialized roles.
It looks like Ethernet will continue to expand in its applications for some time. 10-gigabit Ethernet has freed it from the distance constraints of CSMA/CD. Much effort is being put into carrier-grade Ethernet to let network providers offer Ethernet-based services to their customers for metropolitan and wide area networks (Fouli and Maler, 2009). This application carries Ethernet frames long distances over fiber and calls for better management features to help operators offer reliable, high-quality services. Very high speed networks are also finding uses in backplanes connecting components in large routers or servers. Both of these uses are in addition to that of sending frames between computers in offices.
Probably the main reason for its longevity is that Ethernet is simple and flexible. In practice, simple translates into reliable, cheap, and easy to maintain. Once the hub and switch architecture was adopted, failures became extremely rare. People hesitate to replace something that works perfectly all the time, especially when they know that an awful lot of things in the computer industry work very poorly, so that many so-called ‘‘upgrades’’ are worse than what they replaced.
Simple also translates into cheap. Twisted-pair wiring is relatively inexpensive as are the hardware components. They may start out expensive when there is a transition, for example, new gigabit Ethernet NICs or switches, but they are merely additions to a well established network (not a replacement of it) and the prices fall quickly as the sales volume picks up.
Ethernet is easy to maintain. There is no software to install (other than the drivers) and not much in the way of configuration tables to manage (and get wrong). Also, adding new hosts is as simple as just plugging them in.
Another point is that Ethernet interworks easily with TCP/IP, which has become dominant. IP is a connectionless protocol, so it fits perfectly with Ethernet, which is also connectionless. IP fits much less well with connection-oriented alternatives such as ATM. This mismatch definitely hurt ATM’s chances.
Lastly, and perhaps most importantly, Ethernet has been able to evolve in certain crucial ways. Speeds have gone up by several orders of magnitude and hubs and switches have been introduced, but these changes have not required changing the software and have often allowed the existing cabling to be reused for a time. When a network salesman shows up at a large installation and says ‘‘I have this fantastic new network for you. All you have to do is throw out all your hardware and rewrite all your software,’’ he has a problem.
Many alternative technologies that you have probably not even heard of were faster than Ethernet when they were introduced. As well as ATM, this list includes FDDI (Fiber Distributed Data Interface) and Fibre Channel,† two ringbased optical LANs. Both were incompatible with Ethernet. Neither one made it. They were too complicated, which led to complex chips and high prices. The lesson that should have been learned here was KISS (Keep It Simple, Stupid). Eventually, Ethernet caught up with them in terms of speed, often by borrowing some of their technology, for example, the 4B/5B coding from FDDI and the 8B/10B coding from Fibre Channel. Then they had no advantages left and quietly died off or fell into specialized roles.
It looks like Ethernet will continue to expand in its applications for some time. 10-gigabit Ethernet has freed it from the distance constraints of CSMA/CD. Much effort is being put into carrier-grade Ethernet to let network providers offer Ethernet-based services to their customers for metropolitan and wide area networks (Fouli and Maler, 2009). This application carries Ethernet frames long distances over fiber and calls for better management features to help operators offer reliable, high-quality services. Very high speed networks are also finding uses in backplanes connecting components in large routers or servers. Both of these uses are in addition to that of sending frames between computers in offices.
No comments:
Post a Comment