The purpose of this paper is to present the inadequacies of IPv4 and the improvements made by implementing IPv6 Essays

The purpose of this paper is to present the inadequacies of IPv4 and the improvements made by implementing IPv6 Essays The purpose of this paper is to present the inadequacies of IPv4 and the improvements made by implementing IPv6 Essay The purpose of this paper is to present the inadequacies of IPv4 and the improvements made by implementing IPv6 Essay First, I will cover IPv4. IPv4 was implemented in the late 1980s. Therefore, IPv4 is dated technology. Before the internet explosion, IPv4 was a more than adequate solution to unique internet addressing. However, as the internet grew, and as networks and IP devices expanded and became more popular, it was apparent that a new solution to internet addressing needed to be introduced. IPv4 provides an apparently finite amount of addresses. It is estimated that IPv4 will run out of unique addresses between the years 2005 and 2011, largely due to the tremendous influx of new devices and users. IPv4 is inefficient. Period. The article on zdnet.co.uk points out that the routers that comprise the internet backbone contain routing tables that maintain over 85,000 routes. This seems to be a glaring inefficiency, almost negating the purpose of routers to provide quick and efficient routes. Among other problems with IPv4, security is an issue. Though there are vendor-specific ways to encrypt data on IPv4, no real standardized solution exists. There is certainly a need for an internet standard to address this issue. With the advent of e-commerce and things of the like, security is an issue not to be taken lightly. In order for the next echelon of e-commerce to be traversed, it seems that security and efficiency issues must be resolved. IPv6 seems to be just the tool needed to breathe life back into the internet, and expand the horizons to the broader possibilities that the internet and networking in general can provide. Sounds like Im selling it to you, no? Anyway, IPv6 can bring networks back from the dead and give them new life and reassurance. First and foremost, the issue to limited addressing is eradicated with IPv6. IPv6 allows for 2128 addresses. This new 128-bit address scheme eliminates the possibility of running out of addresses, at least for quite awhile. Another cool feature of IPv6 is the ability to auto-configure IP addresses, almost eliminating the need for DHCP, because the computers will poll others around them and determine an appropriate IP address for itself. This plug n play scheme will allow for wireless devices to travel seamlessly across cells without degradation or differentiation of service, to my understanding. IPv6 also incorporates various elements of the IPv4 header into a flow label; allowing for a simpler header and less relative overhead. A diagram of this is on the last page of this essay, with its source immediately beneath. Optional components once found in the front of an IPv4 header, whether used or not, are now located in an extension header in IPv6, and are only present when used. This also reduces minimum packet size and boosts efficiency. IPv6 utilizes the hierarchical nature of the internet to its advantage. IPv6 is designed to utilize smaller routing tables, thus allowing for faster routes due to smaller search times. The routers will only be aware of other routers connected directly to them, and the IPv6 packet serves as an almost self-steering packet. Regarding security, IPv6 has IPSec encryption incorporated. This solves the problem of the lack standardized encryption and security solutions. One of the drawbacks to IPv6, however, is that it is costly to implement, though it is a worthy (and eventually required, right?) investment. During my research, I can across internet communities dedicated to IPv6 implementation who are already reaping the benefits of implementation. They seem pretty excited, too.

Vertebrates - Vertebrata - the Animal Encyclopedia

Vertebrates - Vertebrata - the Animal Encyclopedia Vertebrates (Vertebrata) are a group of chordates that includes birds, mammals, fishes,  lampreys, amphibians, and reptiles. Vertebrates have a vertebral column in which the notochord is replaced by multiple vertebrae that form a backbone. The vertebrae surround and protect a nerve cord and provide the animal with structural support.  Vertebrates have a well-developed head, a distinct brain that is protected by a skull, and paired sense organs. They also have a highly efficient respiratory system, a muscular pharynx with slits and gills (in terrestrial vertebrates the slits and gills are greatly modified), a muscularized gut, and a chambered heart. Another notable character of vertebrates is their endoskeleton. An endoskeleton is an internal assemblage of notochord, bone or cartilage that provides the animal with structural support. The endoskeleton grows as the animal grows and provides a sturdy framework to which the animals muscles are attached. The vertebral column in vertebrates is one of the groups defining characteristics. In most vertebrates, a notochord is present early in their development. The notochord is a flexible yet supportive rod that runs along the length of the body. As the animal develops, the notochord is replaced by a series of vertebrae that form the vertebral column. Basal vertebrates such as cartilaginous fishes and ray-finned fishes breath using gills. Amphibians have external gills in the larval stage of their development and (in most species) lungs as adults. Higher vertebrates- such as reptiles, birds, and mammals- have lungs instead of gills. For many years, the earliest vertebrates were thought to be the ostracoderms, a group of jawless, bottom-dwelling, filter-feeding marine animals. But during the past decade, researchers have discovered several fossil vertebrates that are older than the ostracoderms. These newly discovered specimens, which are about 530 million years old, include Myllokunmingia and Haikouichthys. These fossils exhibit numerous vertebrate traits such as a heart, paired eyes, and primitive vertebrae. The origin of jaws marked an important point in vertebrate evolution. Jaws enabled vertebrates to capture and consume larger prey than their jawless ancestors. Scientists believe that jaws arose via the modification of the first or second-gill arches. This adaptation is thought to have at first been a way of increasing gill ventilation. Later, as musculature developed and the gill arches bent forward, the structure functioned as jaws. Of all living vertebrates, only the lampreys lack jaws. Key Characteristics The key characteristics of vertebrates include: vertebral columnwell-developed headdistinct brainpaired sense organsefficient respiratory systemmuscular pharynx with slits and gillsmuscularized gutchambered heartendoskeleton Species Diversity Approximately 57,000 species.  Vertebrates account for about 3% of all known species on our planet. The other 97% of species alive today are invertebrates. Classification Vertebrates are classified within the following taxonomic hierarchy: Animals Chordates Vertebrates Vertebrates are divided into the following taxonomic groups: Bony fishes (Osteichthyes) - There are about 29,000 species of bony fishes alive today. Members of this group include ray-finned fishes and lobe-finned fishes. Bony fishes are so named because they have a skeleton made of true bone.Cartilaginous fishes (Chondricthyes) - There are about 970 species of cartilaginous fishes alive today. Members of this group include sharks, rays, skates, and chimaeras. Cartilaginous fishes have a skeleton that is made of cartilage instead of bone.Lampreys and Hagfishes (Agnatha) - There are about 40 species of lamprey alive today. Members of this group include pouched lampreys, Chilean lampreys, Australian lampreys, northern lampreys, and others. Lampreys are jawless vertebrates that have a long narrow body. They lack scales and have a sucker-like mouth.Tetrapods (Tetrapoda) - There are about 23,000 species of tetrapods alive today. Members of this group include birds, mammals, amphibians, and reptiles. Tetrapods are vertebrates with four limbs (or whos e ancestors had four limbs). References Hickman C, Roberts L, Keen S. Animal Diversity. 6th ed. New York: McGraw Hill; 2012. 479 p. Hickman C, Roberts L, Keen S, Larson A, lAnson H, Eisenhour D. Integrated Principles of Zoology 14th ed. Boston MA: McGraw-Hill; 2006. 910 p.