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Router

Router

:This article describes the computer networking device. A wood router is a kind of rotating cutting tool. A router is a computer networking device that forwards data packets across an internetwork toward their destinations, through a process known as routing. Routing occurs at layer 3 (the Network layer) of the OSI seven-layer model.

Function

OSI seven-layer model In non-technical terms, a router acts as a junction between two networks to transfer data packets among them. A router is essentially different from a switch that connects devices to form a Local Area Network (LAN). One easy illustration for the different functions of routers and switches is to think of switches as neighborhood streets, and the router as the intersections with the street signs. Each house on the street has an address within a range on the block. In the same way, a switch connects various devices each with their own IP address(es) on a LAN. However, the switch knows nothing about IP addresses except its own management address. Routers connect networks together the way that onramps or major intersections connect streets to both highways and freeways, etc. The street signs at the intersection (routing table) show which way the packets need to flow. So for example, a router at home connects the Internet Service Provider's network (usually on an Internet address) together with the LAN in the home (typically using a range of private IP addresses) and a single broadcast domain. The switch connects devices together to form the LAN. Sometimes the switch and the router are combined together in one single package sold as a multiple port router. In order to route packets, a router communicates with other routers using routing protocols and using this information creates and maintains a "routing table". The routing table stores the best routes to certain network destinations, the "routing metrics" associated with those routes, and the path to the next hop router. See the routing article for a more detailed discussion of how this works. Routing is most commonly associated with the Internet Protocol, although other less-popular routed protocols are in use.

Types of routers

Internet Protocol In the original era of routing (from the mid-1970s through the 1980s), general-purpose mini-computers served as routers. Although general-purpose computers can perform routing, modern high-speed routers are highly specialised computers, generally with extra hardware added to accelerate both common routing functions such as packet forwarding and specialised functions such as IPsec encryption. Other changes also improve reliability, such as using DC power rather than line power (which can be provided from batteries in data centers), and using solid-state rather than magnetic storage for program loading. Large modern routers have thus come to resemble telephone switches, with whose technology they are currently converging and may eventually replace, whilst small routers have become a common household item. A router that connects clients to the Internet is called an edge router. A router that serves solely to transmit data between other routers, e.g. inside the network of an Internet service provider, is called a core router. A router is normally used to connect at least two networks, but a special variety of router is the one-armed router, used to route packets in a virtual LAN environment. In the case of a one-armed router the multiple attachments to different networks are all over the same physical link. In mobile ad-hoc networks every host performs routing and forwarding by itself, while in wired networks there is usually just one router for a whole broadcast domain. In recent times many routing functions have been added to LAN switches (a marketing term for high-speed bridges), creating "Layer 2/3 Switches" which route traffic at near wire speed. Routers are also now being implemented as Internet gateways, primarily for small networks like those used in homes and small offices. This application is mainly where the Internet connection is an always-on broadband connection like cable modem or DSL. These are routers in the true sense because they join two networks together - the WAN and the LAN – and have a routing table. Often these small routers support the RIP protocol, although in a home application the routing function does not serve much purpose since there are only two ways to go - the WAN and the LAN. In addition, these routers typically provide DHCP, NAT, DMZ and Firewall services. Sometimes these routers can provide content filtering and VPN. Typically they are used in conjunction with either a cable modem or DSL modem, but that function can also be built-in.

Manufacturers of routers

There are a number manufacturers of routers including:
- 3Com [http://www.3com.com (www.3com.com)]
- Alcatel [http://www.alcatel.com (www.alcatel.com)]
- Belkin [http://www.belkin.com (www.belkin.com)]
- Cisco Systems, Inc. [http://www.cisco.com (www.cisco.com)]
- D-Link Systems [http://www.dlink.com (www.dlink.com)]
- Enterasys Networks [http://www.enterasys.com (www.enterasys.com)]
- Hewlett-Packard [http://www.hp.com (www.hp.com)]
- Huawei Technologies [http://www.huawei.com (www.huawei.com)]
- Juniper Networks [http://www.juniper.net (www.juniper.net)]
- Linksys [http://www.linksys.com (www.linksys.com)]
- Mikrotik [http://www.mikrotik.com (www.mikrotik.com)]
- Motorola [http://www.motorola.com (www.motorola.com)]
- NETGEAR [http://www.netgear.com (www.netgear.com)]
- Nortel [http://www.nortelnetworks.com (www.nortelnetworks.com)]
- Pivotal Networking [http://www.pivnet.com (www.pivnet.com)]
- Siemens AG [http://www.siemens.com (www.siemens.com)]
- SMC Networks [http://www.smc.com (www.smc.com)]
- Tellabs [http://www.tellabs.com (www.tellabs.com)]
- MRV Communications [http://www.mrv.com (www.mrv.com)]
- Zoom Telephonics [http://www.zoom.com (www.zoom.com)]
- Trendware [http://www.trendware.com (www.trendware.com)]

"Software" routers

With the proper software, ordinary PCs can be made into routers:
- [http://www.microsoft.com/windowsxp/using/networking/learnmore/ics.mspx Windows XP Internet Connection Sharing]
- [http://www.macdevcenter.com/pub/a/mac/2003/11/11/panther_internet.html Mac OS X Internet Sharing]
- Basic Internet Routing Daemon [http://bird.network.cz (bird.network.cz)]
- fdgw [http://www.fml.org/software/fdgw/ (www.fml.org/software/fdgw/)]
- FREESCO [http://www.freesco.org/ (www.freesco.org/)]
- Coyote Linux [http://www.coyotelinux.com (www.coyotelinux.com)]
- GNU Zebra [http://www.zebra.org (www.zebra.org)]
- IPCop [http://www.ipcop.org (www.ipcop.org)]
- SmoothWall [http://smoothwall.org (smoothwall.org)]
- The Linux Router Project^[1]
- m0n0wall [http://m0n0.ch/wall/ (m0n0.ch/wall)]
- FreeBSD [http://www.freebsd.org (www.freebsd.org) ]
- NetBSD [http://www.netbsd.org (www.netbsd.org) ]
- OpenBSD [http://www.openbsd.org (www.openbsd.org) ] ^[1]Most Unix-like operating systems include all necessary software to perform routing; the Linux Router Project is an example of a Linux distribution that specialises in routing.

External links

- [http://www.bsdrouter.org www.bsdrouter.org] - website that covers router software based on BSD operating systems
- [http://computer.howstuffworks.com/router.htm/printable HowStuffWorks: How Routers Work by Curt Franklin] Category:Computer networks Category:Internet architecture
- ja:ルーター

Wood router

A router is a woodworking tool used to rout out (hollow out) an area in the face of a piece of wood. It was a tool particularly used by pattern makers and consisted of a broad-based wooden hand plane with a narrow blade projecting well beyond its sole. Since about 1960, it has been replaced by the modern spindle router, which was designed for the same work. Further refinement has produced the even more recent plunging spindle router, which is even better adapted for many types of work. Today, traditional hand-powered routers are often called router planes.

Moulding

The spindle router has lent itself to the finer end of the scale of work done by a moulding spindle. That is to say it is able to cut grooves, edge moulding, and chamfer or radius the edge of a piece of wood. It is also possible to use it for cutting some joints. The shape of cut that is created is determined by the size and shape of the bit (cutter) held in the collet and the depth by the depth adjustment of the sole plate.

Features of the modern spindle router

The tool usually consists of a base housing a vertically mounted universal electric motor with a collet on the end of its shaft. The bit is height-adjustable to allow protrusion through an opening in a flat sole plate, usually via adjusting the motor-mounting height (the mechanism of adjustment is widely varied among manufacturers). Control of the router is derived from a handle or knob on each side of the device, or by the more recently developed "D-handle". There are two standard types of router — plunge and fixed. When using a plunge-base router, the sole of the base is placed on the face of the work with the cutting bit raised above the work, then the motor is turned on and the cutter is lowered into the work. With a fixed-base router, the cut depth is set before the tool is turned on. The sole plate is then either rested flat on the workpiece overhanging the edge so that the cutting bit is not contacting the work (and then entering the work from the side once the motor is turned on), or the sole plate is placed at an angle with the bit above the work and the bit is "rocked" over into the work once the motor is turned on. In each case, the bit cuts its way in, but the plunge router does it in a more refined way. The baseplate (sole plate) is generally circular (though this, too, varies by individual models) and may be used in conjunction with a fence attached to the base, which then braces the router against the edge of the work, or via a straightedge clamped across the work to obtain a straight cut. Without this, the varying reaction of the wood against the torque of the tool makes it impossible to control with the precision normally required. As an alternative, the tool can also be mounted in an inverted orientation below [http://www.inside-woodworking.com/router/router-tables.html router tables] and used as a miniature spindle shaper. The machine is mounted below the table in the manner akin to a circular saw mounted like a table saw. With such a set-up, it is often advisable that the work be passed over it along a fence. With some router table arrangements it is possible to adjust the bench to give the effect of tilting a saw bench so as to cut with the axis of the tool at an angle other than 90° to the face of the work. shaper

Available cutters

Router bits come in hundreds of varieties to create either decorative effects or joinery aids. Generally, they are classified as either high-speed steel (HSS) or carbide-tipped, however some recent innovations such as all-carbide bits provide even more variety for specialized tasks. Aside from the materials they are made of, bits can be classified as edge bits or non-edge bits, and whether the bit is designed to be anti-kickback. Edge bits have a small wheel bearing to act as a fence against the work in making edge mouldings. Non-edge bits require the use of a fence, either on a router table or attached to the work or router. Anti-kickback bits employ added non-cutting bit material around the circumference of the bit's shoulders which serves to limit feed-rate and thereby reduce the chance that the workpiece is pushed too deeply into the bit, causing the cutting edge to be unable to compensate, which results in significant kickback. Bits also differ by the diameter of their shank, with ½ inch, 3/8 inch, 8mm, and ¼ inch shanks (ordered from thickest to thinnest) being the most common. Half-inch bits cost more but are less prone to vibration (giving smoother cuts) and are less likely to break than the smaller sizes. The bit shank and router collet sizes must match. Many routers come with removable collets for the popular shank sizes (although in the United States the 3/8-inch and 8 mm sizes are often only available for extra cost). Many modern routers allow the speed of the bit's rotation to be varied. A slower rotation allows bits of larger cutting diameter to be used safely. Typical speeds range from 8,000 to 30,0000 rpm.

Variations on the theme

A tool similar to a router, but designed to hold smaller cutting bits - thereby making it easier to handle for small jobs - is a laminate trimmer. Another related tool, called a spindle moulder (UK) or shaper (North America), is used to hold larger cutter heads and can be used for deeper or larger-diameter cuts. Some profile cutters use a cutting head reminiscent of a spindle router. These should not be confused with profile cutters used for steel plate which use a flame as the cutting method.

Publicity blurb

The router was described as "the most versatile tool in the world" by Jeremy Broun in his book, "The Incredible Router". Hylton and Matlack also describe the router as a versatile tool (see Books below): "You can use it in just about every aspect of a job but assembly ... used creatively, it will do almost any kind of cutting or shaping of wood." However, custom baseplates, templates, or jigs — tools that help guide the router or the workpiece through a controlled motion — are typically needed for more complex cuts.

Books

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External links

- [http://www.patwarner.com/ Pat Warner's Router Woodworking]
- [http://www.inside-woodworking.com/router/router-tables.html Router Tables], Guide on routing at Inside-Woodworking.com Category:Tools Router

Computer networking device

Computer networking devices are units that mediate data in a computer network. Computer networking devices are also called network equipment, Intermediate Systems (IS) or InterWorking Unit (IWU). Units which are the last receiver or generate data are called hosts or data terminal equipment.

List of computer networking devices

Common basic network devices:
- gateway: device sitting at a network node for interfacing with another network that uses different protocols. Works on OSI layers 4 to 7.
- router: a specialized network device that determines the next network point to which to forward a data packet toward its destination. Unlike a gateway, it cannot interface different protocols. Works on OSI layer 3.
- bridge: a device that connects multiple network segments along the data link layer. Works on OSI layer 2.
- switch: a device that allocates traffic from one network segment to certain lines (intended destination(s)) which connect the segment to another network segment. So unlike a hub a switch splits the network traffic and sends it to different destinations rather than to all systems on the network. Works on OSI layer 2.
- Ethernet hub: connects multiple Ethernet segments together making them act as a single segment. When using a hub, every attached device shares the same broadcast domain and the same collision domain. Therefore, only one computer connected to the hub is able to transmit at a time. Depending on the network topology, the hub provides a basic level 1 OSI model connection among the network objects (workstations, servers, etc). It provides bandwidth which is shared among all the objects, compared to switches, which provide a dedicated connection between individual nodes. Works on OSI layer 1.
- repeater: device to amplify or regenerate digital signals received while setting them from one part of a network into another. Works on OSI layer 1. Some hybrid network devices:
- multilayer switch: a switch which, in addition to switching on OSI layer 2, provides functionality at higher protocol layers.
- protocol converter: a hardware device that converts between two different types of transmissions, such as asynchronous and synchronous transmissions.
- Brouters: Combine router and bridge functionality and are therefore working on OSI layers 2 and 3.
- Media hub: Connects a computer network to a home theatre Hardware or software components that typically sit on the connection point of different networks, e.g. between an internal network and an external network:
- proxy: computer network service which allows clients to make indirect network connections to other network services
- firewall: a piece of hardware or software put on the network to prevent some communications forbidden by the network policy Other hardware for establishing networks or dial-up connections:
- multiplexer: device that combines several electrical signals into a single signal
- network interface card: a piece of computer hardware to allow the attached computer to communicate by network
- modem: device that modulates an analog "carrier" signal (such as sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information, as a computer communicating with another computer over the telephone network
- ISDN terminal adapter (TA): a specialized gateway for ISDN
- line driver : a device to increase transmission distance by amplifying the signal. Base-band networks only.

Network layer

The network layer is level three of the seven level OSI model. It responds to service requests from the transport layer and issues service requests to the data link layer. The network layer addresses messages and translates logical addresses and names into physical addresses. It also determines the route from the source to the destination computer and manages traffic problems, such as switching, routing, and controlling the congestion of data packets. In essence, the network layer is responsible for end to end (source to destination) packet delivery, whereas the data link layer is responsible for node to node (hop to hop) packet delivery. The network layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer. The Network layer performs network routing, flow control, network segmentation/desegmentation, and error control functions. The network layer deals with transmitting information all the way from its source to its destination - and transmitting things from anywhere you like, to anywhere you like. If you can't contact a place at the network layer, then you can't contact that place at all. However, it does it in a very basic way, without error detection or flow control, or anything else. Here are some things that the network layer needs to address:
- Is the network connection-oriented or connectionless? For example, snail mail is connectionless, because you can send a letter to someone without them doing anything and they will receive the letter. On the other hand, the telephone system is connection-oriented, because the other party has to pick up the phone before you can talk to them.
- What are the Global Addresses? Everybody in the network needs to have a unique address which determines who they are. This address will normally be hierarchical, so you can be "Fred Murphy" to Dubliners, or "Fred Murphy, Dublin" to people in Ireland, or "Fred Murphy, Dublin, Ireland" to people anywhere in the world. On the internet, these addresses are known as IP Numbers.
- How do you forward a message? This is of particular interest to mobile applications, where a user may rapidly move from place to place, and it must be arranged that his messages follow him. Version 4 of the Internet Protocol (IPv4) doesn't really allow for this, though it has been hacked somewhat since its inception. Fortunately, the forthcoming IPv6 has a much better designed solution, which should make these kinds of applications much smoother. In the traditional postage system (commonly referred to as snail mail) this role is provided by the postman (to some extent).

Examples

- Internet Protocol
- ICMP
- Internet Datagram Protocol
- IPX
- NWLink
- Appletalk/DDP
- IPSec

Local area network

A local area network (LAN) is a computer network covering a small local area, like a home, office, or small group of buildings such as a college. Current LANs are most likely to be based on switched Ethernet or Wi-Fi technology running at from 10 to 1000Mb/s (megabits per second). The defining characteristics of LANs in contrast to WANs are: (a) much higher data rates, (b) smaller geographic range and (c) they do not involve leased telecommunication lines.

Technical aspects

Although switched Ethernet is now most common at the physical layer, and TCP/IP as a protocol, historically many different options have been used (see below) and some continue to be popular in niche areas. Larger LANs will have redundant links, and routers or switches capable of using spanning tree protocol and similar techniques to recover from failed links. Many LANs will have connections to other LANs via routers and leased lines to create a WAN. Most will also have connections to the large public network known as the Internet, and links to other LANs can be 'tunnelled' across this using VPN technologies.

History

In the days before personal computers, a site might have just one central computer, with users accessing this via computer terminals over simple low-speed cabling. Networks such as IBM's SNA (Systems Network Architecture) were aimed at linking terminals or other mainframes at remote sites over leased lines—hence these were wide area networks. The first LANs were created in the late 1970s and used to create high-speed links between several large central computers at one site. Of many competing systems created at this time, Ethernet and ARCNET were the most popular. The growth of CP/M and then DOS based personal computer meant that a single site began to have dozens or even hundreds of computers. The initial attraction of networking these was to share disk and printers, which were both very expensive at the time. There was much enthusiasm for the concept and for several years from about 1983 onward computer industry pundits would regularly declare the coming year to be “the year of the LAN”. In reality the concept was marred by proliferation of incompatible physical layer and network protocol implementations, and confusion over how best to share resources. Typically each vendor would have their own type of network card, cabling, protocol, and network operating system. A solution appeared with the advent of Novell NetWare which gave: (a) even-handed support for the 40 or so competing card/cable types, and (b) a much more sophisticated operating system than most of its competitors. NetWare dominated the personal computer LAN business from early after its introduction in 1983 until the mid 1990s when Microsoft introduced Windows NT Advanced Server and Windows for Workgroups. Of the competitors to NetWare, only Banyan Vines had comparable technical strengths, but Banyan never gained a secure base. Microsoft and 3Com worked together to create a simple network operating system which formed the base of 3Com's 3+Share, Microsoft's LAN Manager and IBM's LAN Server. None of these was particularly successful. In this same timeframe Unix computer workstation from vendors such as Sun, HP, Silicon Graphics, Intergraph, NeXT and Apollo were using TCP/IP based networking. Although this market segment is now much reduced, the technologies developed in this area continue to be influential on the Internet and in both Linux and Apple Mac OS X networking.

References

- Charp, S. (Ed.). (1994). Networking & telecommunications. "T.H.E." ("Technical Horizons in Education"), 21(10). (EJ 483 802-807)
- Charp, S. (Ed.). (1995). Networking & telecommunications. "T.H.E." ("Technical Horizons in Education"), 22(9). (EJ 501 732-735)
- Communications, computers, and networks. (1991). [Special Issue.] "Scientific American," 265(3).
- Ellis, T. I. (1984). "Microcomputers in the school office. ERIC Digest." Syracuse, NY: ERIC Clearinghouse on Education Management. (ED 259 451)
- Klausmeier, J. (1984). "Networking and microcomputers. ERIC Digest." Syracuse, NY: ERIC Clearinghouse on Information Resources. (ED 253 256)
- Neubarth, M. (Ed.). (1995, October). The Internet in education. [Special issue]. "Internet World," 6(10). (ERIC ED pending, IR 531 431-438)
- Rienhold, F. (1989). "Use of local area networks in schools. ERIC Digest." Syracuse, NY: ERIC Clearinghouse on Information Resources. (ED 316 249)

External links

- [http://www.ericdigests.org/1996-3/local.htm Local Area Networks for K-12 Schools]
- [http://www.ericdigests.org/pre-9214/local.htm Use of Local Area Networks in Schools.]
- [http://www.ericdigests.org/pre-922/office.htm Microcomputers in the School Office]
- [http://compnetworking.about.com/cs/homenetworking/a/homenetguide_2.htm How to Build a Wireless Home Network (Tutorial)]
- [http://www.homenetworkhelp.info Home Network and Computer Help (Tutorials and help)] Category:Computer networks Category:Office equipment ja:Local Area Network th:แลน

IP address

An IP address (Internet Protocol address) is a unique number that devices use in order to identify and communicate with each other on a network utilizing the Internet Protocol standard. Any participating device — including routers, computers, time-servers, internet FAX machines, and some telephones — must have its own unique address. This allows information passed onwards on behalf of the sender to indicate where to send it next, and for the receiver of the information to know that it is the intended destination. The numbers currently used in IP addresses range from 0.0.0.0 to 255.255.255.255, though some of these values are reserved for specific purposes. This does not provide enough possibilities for every internet device to have its own permanent number. Subnet routing, Network Address Translation and the Dynamic Host Configuration Protocol (DHCP) server all allow local networks to use the same IP addresses as other networks elsewhere though both are connected to the Internet. Devices such as network printers, web servers and email servers are often allocated static IP addresses so they can always be found. IP addresses are conceptually similar to phone numbers, except they are used in LANs (Local Area Network), WANs (Wide Area Network), and the Internet. Because the numbers are not easy for humans to remember, the Domain Name System provides a service analogous to an address book lookup called "domain name resolution" or "name resolution". Special DNS servers on the internet are dedicated to performing the translation from a domain name to an IP address and v.v.

More detail

The Internet Protocol (IP) knows each logical host interface by a number, the IP address. On any given network, this number must be unique among all the host interfaces that communicate through this network. Users of the Internet are sometimes given a host name in addition to their numerical IP address by their Internet service provider. The IP addresses of users browsing the world wide web are used to enable communications with the server of the web site. Also, it is usually in the header of email messages one sends. In fact, for all programs that utilize the TCP/IP protocol, the sender IP address and destination IP address are required in order to establish communications and send data. Depending on one's Internet connection the IP address can be the same every time one connects (called a static IP address), or different every time one connects, (called a dynamic IP address). In order to use a dynamic IP address, there must exist a server which can provide the address. IP addresses are usually given out through a server service called DHCP or the Dynamic Host Configuration Protocol. If a static address is used, it must be manually programmed into parameters of the device's network interface. Internet addresses are needed not only for unique enumeration of hosted interfaces, but also for routing purposes, therefore a high fraction of them are always unused or reserved. The unique nature of IP addresses makes it possible in many situations to track which computer — and by extension, which person — has sent a message or engaged in some other activity on the Internet. This information has been used by law enforcement authorities to identify criminal suspects. The dynamically-assigned nature of many IP addresses can make this even more difficult.

IP version 4

Addressing

In version 4 of the Internet protocol (IPv4), the current standard protocol for the Internet, IP addresses consist of 32 bits, which makes for 4,294,967,296 (over 4 billion) unique host interface addresses in theory. In practice, because addresses are allocated in blocks, many unused addresses are unavailable (much like unused phone numbers in a sparsely-populated area code), so that there is some pressure to extend the address range via IP version 6 (see below). IPv4 addresses are commonly expressed as a dotted quad, four octets (8 bits) separated by periods. The host known as www.wikipedia.org currently has the number 3482223596, written as 207.142.131.236 in base-256: 3482223596 equals 207×256³ + 142×256² + 131×256¹ + 236×256⁰. (Resolving the name "www.wikipedia.org" to its associated number is handled by Domain Name System servers.) IPv4 addresses were originally divided into two parts: the network and the host. A later change increased that to three parts: the network, the subnetwork, and the host, in that order. However, with the advent of classless inter-domain routing (CIDR), this distinction is no longer meaningful, and the address can have an arbitrary number of levels of hierarchy. (Technically, this was already true any time after the advent of subnets, since a site could elect to have more than one level of subnetting inside a network number.) For more information on current IPv4 address ranges, see tables on class ranges and special (reserved) ranges. See also: Classful network

Assignment

Each interface of a device is assigned, at least conceptionally, a unique IP address. In practice, some interfaces may be unnumbered, and many addresses are not globally unique. The actual assignment of an address is not arbitrary. The fundamental principle of routing, that addresses encode information about a device's location within a network, implies that an address assigned to one part of a network will not function in another part of the network. A hierarchical structure, standardized by CIDR and overseen by the Internet Assigned Numbers Authority (IANA) and its Regional Internet Registries (RIRs), manages the assignment of Internet address worldwide. Each RIR maintains a publically searchable WHOIS database that provides information about IP address assignments; information from these databases plays a central role in numerous tools which attempt to locate IP addresses geographically. (See List of assigned Class A IP addresses for a list of some of the large Class A address blocks currently assigned.)

Exhaustion

Some private IP address space has been allocated via RFC 1918. This means the addresses are available for any use by anyone and therefore the same RFC 1918 IP addresses can be reused. However they are not routable on the Internet. They are used extensively due to the shortage of registerable addresses. Network address translation (NAT) is required to connect those networks to the Internet. While a number of measures have been taken to conserve the limited existing IPv4 address space (such as the use of NAT and Private Addressing), the number of 32-bit IP addresses is not sufficient to accommodate the long-term growth of the Internet. For this reason, the plan is that the Internet 128-bit IPv6 addressing scheme will be adopted over the next 5 to 15 years. See also: IPv4 address exhaustion

IP version 5

What would be considered IPv5 existed only as an experimental non-IP real time streaming protocol called ST2, described in RFC 1819. This protocol was abandoned; RSVP has replaced it to some degree.

IP version 6

In IPv6, the new (but not yet widely deployed) standard protocol for the Internet, addresses are 128 bits wide, which, even with generous assignment of netblocks, should suffice for the foreseeable future. In theory, there would be exactly 2¹²⁸, or about 3.403 × 10³⁸ unique host interface addresses. If the earth were made entirely out of 1 cubic millimeter grains of sand, then you could give a unique address to each grain in 300 million planets the size of the earth. This large address space will be sparsely populated, which makes it possible to again encode more routing information into the addresses themselves.

Addressing

A version 6 address is written as eight 4-digit hexadecimal numbers separated by colons. For readability, addresses may be shortened in two ways. Within each colon-delimited section, leading zeroes may be truncated. Secondly, one string of zeroes (and only one) may be replaced with two colons (::). For example, all of the following addresses are equivalent:
- 1080:0000:0000:0000:0000:0034:0000:417A
- 1080:0:0:0:0:34:0:417A
- 1080::34:0:417A Global unicast IPv6 addresses are constructed as two parts: a 64-bit routing part followed by a 64-bit host identifier. Netblocks are specified as in the modern alternative for IPv4: network number, followed by a slash, and the number of relevant bits of the network number (in decimal). Example: 12AB::CD30:0:0:0:0/60 includes all addresses starting with 12AB00000000CD3. IPv6 has many improvements over IPv4 other than just bigger address space, including autorenumbering and mandatory support for IPsec. Further reading: Internet RFCs including RFC 791, RFC 1519 (IPv4 addresses), and RFC 2373 (IPv6 addresses).

External links

- [http://www.linuxjournal.com/article/7856 Introduction to geolocation by IP address]
- [http://www.circleid.com/community/topics/view/IP%20Addressing/ Articles on CircleID about IP addressing]
- [http://www.securityfocus.com/infocus/1674 IP Spoofing: An Introduction]
- [http://www.byte.com/art/9602/sec16/art4.htm IP-Address Management on LANs] - article in Byte magazine
- [http://www.circleid.com/posts/ip_address_allocation_vs_internet_production_i_understanding_the_relationsh/ Introduction to IP address allocation]
- [http://seeyourip.info/ IP-Address: detailed text description]
- [http://www.hostip.info/ Community project to geotarget IP addresses] Category:Computing Category:Computer networks Category:Information technology Category:Internet architecture Category:Identifiers als:IP-Adresse ko:IP 주소 ja:IPアドレス simple:IP address th:หมายเลขไอพี

IP address

More detail

IP version 4

Addressing

Assignment

Exhaustion

IP version 5

IP version 6

Addressing

External links

Élan

Élan Corporation plc (, ) is a major drugs firm based in Athlone, County Westmeath, Ireland. In the late 1990's its value as a PLC on the Irish Stock Exchange reached over €20bn. It has secondary listings on the London Stock Exchange and the New York Stock Exchange. It was one of Ireland's major business success stories. However in the early years of 2000's an accounting scandal and investor reactions to the global slump, caused a major devaluation resulting in a share price slump of over 90%. Since then the company has regained its growth path under the reign of a new American CEO Kelly Martin. Today, Élan still employs over 2,000 people in Ireland. It is listed on the New York Stock Exchange as ELN, the Irish Stock Exchange as ELN.I, and the London Stock Exchange as ELN.L. Élan is currently focusing its research on a ground-breaking drug for Alzheimer's disease. On 28th February 2005, Élan announced that it was withdrawing its Tysabri drug, after reports that a patient died after usage. This has led to its share price dropping by 70%.

External links

- [http://www.bioscorpio.com/elan_corp_plc.htm Information about Élan]
- [http://en.wikinews.org/wiki/Elan%3B_Biogen_withdraw_MS_drug_after_death Wikinews report of Tysabri withdrawal]
- [http://www.ise.ie/app/equityDetails.asp?equity=530 Élan stock on the Irish Stock Exchange ] Elan Elan Elan Elan

Private IP address

In Internet terminology, a private network is a network that uses RFC 1918 private IP address space and is not connected to the public Internet. Private networks are available for any use by anyone and therefore the same private IP addresses can be reused. Private networks are becoming quite common in office local area network (LAN) designs, as many organizations do not see a need for globally unique IP addresses for every computer, printer and other device that the organizations use. Another reason for the extensive use of private IP addresses is the shortage of publicly registerable IP addresses. IPv6 was created to alleviate this shortage, but is yet to be in widespread use. Private IP addresses also provide a basic form of security as in a typical network configuration of this type it is not possible for the outside world (Internet) to establish a connection directly to a host using these addresses. Network address translation (NAT) devices are required to connect private networks to the Internet. The NAT device will have at least one "real" or publicly-reachable address, and will route traffic destined for the public Internet through that address. This can cause problems, however, when organizations try to connect two networks that both use private address spaces. There is the potential for clashes and routing problems if both networks use the same IPs for their private networks, or rely on NAT to connect them through the Internet. Specifically, the networks are: RFC 1597 was the original specification but is now for historical purposes only. To reduce load on the root nameservers caused by reverse DNS lookups for these IP addresses, a system of "black-hole" nameservers is provided by anycast network AS112. [http://www.as112.net/]

Link-Local addresses

A second set of private network is the link-local address range codified in RFCs [http://www.ietf.org/rfc/rfc3330.txt 3330] and [http://www.ietf.org/rfc/rfc3927.txt 3927]. The intention behind these RFCs is to provide an IP address (and by implication, network connectivity) without a DHCP server being available and without having to configure a network address manually. The subnet 169.254/16 has been set aside for this. If a network address cannot be obtained via DHCP, an address from 169.254.1.0 to 169.254.254.0 is assigned randomly. The standard prescribes that address collisions must be handled gracefully. The subnets 169.254.0/24 and 169.254.255/24 have been set aside for future use. As with the private network addresses defined in RFC 1918, packets from this subnet must not be routed to the internet at large.

External links

- RFC 1918 – ([http://www.rfcsearch.org/rfcview/RFC/1918.html html version]) Category:Internet architecture

Broadcast domain

A broadcast domain is a logical area in a computer network where any computer connected to the computer network can directly transmit to any other in the domain without having to go through a routing device, providing they share the same subnet and gateway address and are in the same VLAN, (default or installed). (If VLANS are installed on a switch, a router will be needed to route between VLANS in the same network). More specifically it is an area of the computer network made up of all the computers and networking devices able to be reached by sending a frame to the data link layer broadcast address. In a very basic network where hubs are used to connect the computers, rather than switches or routers, you could say it's pretty much like the post office clerk checking the mail. One clerk has to look at mail every time to confirm that the mail is not for himself/herself. So when one mail (signal) is sent from one point, all the other points in the network will have to check in order to confirm that the mail (signal) is not for themselves. Compare with Collision domain. Category:Computer networks

Élan

External links

Routing protocols

Routing protocols allow different computer networks to communicate. Some commonly used routing protocols are:
- Router Information Protocol (RIP)
- Open Shortest Path First (OSPF)
- Interior Gateway Routing Protocol (IGRP)
- Enhanced IGRP (EIGRP)
- Border Gateway Protocol (BGP)
- Intermediate System to Intermediate System (IS-IS) IGRP and EIGRP are proprietary Cisco protocols, and are supported on Cisco routers or other vendors' routers to which Cisco has licensed the technology.
- Category:Routing

Internet protocol

Internet protocol may refer to:
- The Internet Protocol, a data-oriented protocol used for communicating data across a packet-switched internetwork.
- The Internet protocol suite, a set of communications protocols that implement the protocol stack on which the Internet runs.

1970s

The 1970s in its most obvious sense refers to the decade between 1970 and 1979. The decade is remembered by many as the 1960s rapidly running out of steam, and the gloom of recession replacing the optimism of the 1960s Flower Power era. The United States, which had become an influential global power, experienced much of the transition. While the sixties saw social activism, society became more self-absorbed in the seventies. Analyst and writer Tom Wolfe epitomized this feeling in 1976, calling the seventies the "Me Decade." Music became at once more introspective with the singer-songwriter movement and more carefree with the rise of disco music. As the decade continued on, the American world view became apprehensive, with continuing inner-city poverty and rising urban crime rates, the Watergate hearings broadcast on television, and the Vietnam War still fresh in the national memory. Network, arguably one of the decade's most representative films, dealt with narcissism and paranoia as violence escalated in the Middle East and America was crippled by the Oil Shock of 1973. As the economy slipped, the use of recreational drugs increased and many began to fear purported cults such as the Children of God. By the end of the decade the feminist movement had helped improve women's working conditions and environmentalism had become a major cause in the United States and Europe. While the United States experienced recession, the economy of Japan rose to claim the top spot on the world stage. The economies of many third world countries continued to bloom in the early 1970s through the green revolution. They might have thrived and become stable in the way that Europe recovered after the war through the Marshall Plan; however, the economic growth was stunted by the oil crisis. In 1973, foreign peacekeepers fled Vietnam, and the war that had lasted for nearly a decade ended with the Paris Peace Accords and communism continuing to spread. In neighboring Cambodia, several million citizens were executed by communist leader Pol Pot. Meanwhile, black South Africans still remained under apartheid following the death of activist Steve Biko.

Worldwide trends in the Seventies

The ethos of the 1970s emerged from a transition of the global social structure. It reflected the transition from the decline of colonial imperialism since the end of World War II to globalization and the rise of a new middle class in the developing world. Globally, the 1970s had several features that were similar and definitive across economic levels and regions. These aspects and essence that make up global essence of the 1970s are the defining points of the 1970s: the Bretton Woods system and its subsequent failure, the impact of the contraceptive pill on social-interactional dynamics, and the oil shock of 1973. The developing nations experienced economic growth that came in the wake of political independence. However, several African economies declined and political states became dictatorial regimes. Many Middle Eastern democracies crumbled into chaotic regimes with pseudo democratic governments. The 1970s ethos in much of the developing world was characterized by:
- the incessant need to redefine social norms to newer socioeconomic systems,
- the sheer pace at which they need to adapt to new social influences along with the need to integrate it to their native cultural context, and
- the constant aspiration for a more egalitarian society in cultures that were long colonised and have an even longer history of hierarchical social structure. The green revolution of the late 1960s brought about self sufficiency in many developing economies. At the same time an increasing number of people began to seek urban prosperity over agrarian life. This consequently saw the duality of transition of diverse interaction across social communities amid increasing information blockade across social class. Other common global ethos of the seventies world include: increasingly flexible and varied gender roles for women. Women could now enter the work force and not just be housewives. However the gender role of men remained as that of a bread-winner. The period also saw unprecedented socioeconomic impact of an ever-increasing number of women entering the non-agrarian economic workforce, and the sweeping cultural-religious impact of the Iranian revolution toward the end of the 1970s. The global experience of the cultural transition of the 1970s and an experience of a global zeitgeist revealed the interdependence of economies since World War II, and showed the huge impact of American economic policies on the world.

Economy of the Seventies

The developed economies of the world, the 1970s adversely distinguished itself from the prosperous postwar period between 1945 and 1969. Then, the world economy was buoyed by the Marshall Plan and the robust American economy. However, the high standing enjoyed by the American economy gradually became discomposed by loose domestic and war spending, particularly the Vietnam war. The oil shock of 1973 added to the existing ailments and conjured high inflation throughout much of the world for the rest of the decade. World leaders, such as James Callaghan of the United Kingdom, and Jimmy Carter of the United States, could not control it, causing their support to dwindle. Although there was no economic depression, the period is known for "stagflation", in which inflation and unemployment steadily increased, therefore leading to lower economic growth rates than previous decades. In Eastern Europe, Soviet-style command economies began showing signs of stagnation, in which successes were persistently dogged by setbacks. The oil shock increased East European, particularly Soviet, exports, but agriculture became a growing annoyance to such economies.

Oil crisis

Jimmy Carter, were common throughout the Western world. Also common were long lines to receive rationed petrol products.]] Economically, the seventies were marked by the energy crisis which peaked in 1973 and 1979 (see 1973 oil crisis and 1979 oil crisis). After the first oil shock in 1973, gasoline was rationed in many countries. Europe particularly depended on the Middle East for oil; the US was also affected even though it had its own oil reserves. Many European countries introduced car-free days. In the US, customers with a license plate ending in an odd number were only allowed to buy gasoline on odd-numbered days, while even-numbered plate-holders could only purchase gasoline on even-numbered days. The experience that oil reserves were not endless and technological development was not sustainable without harming the environment ended the age of modernism. As a result, ecological awareness rose.

Social movements

Environmentalism

The seventies touched off a mainstream affirmation of the environmental issues early activists from the '60s, such as Rachel Carson, warned about. The moon landing that had occurred at the end of the previous decade transmitted back concrete images of the earth as an integrated, life-supporting system and shaped a public willingness to preserve nature. On April 22, 1970, the United States celebrated its first Earth Day in which over two thousand colleges and universities and roughly ten thousand primary and secondary schools participated. Over the course of the decade, in the US a series of environmentally friendly legislation would be passed. Notable actions included the establishment of the Environmental Protection Agency in 1970, the passage of Clean Water Act in 1972, and the enactment of the Endangered Species Act the next year. The takeoff of environmental thought rose parallel to the increased usage of nuclear power over fossil fuels. However, with the increasing expenses of nuclear power the opposition likewise grew. [http://www.globalpublicmedia.com/articles/180] Opposition to nuclear power became widespread in reaction to the partial meltdown of the Three Mile Island nuclear plant on March 28, 1979.

Feminism

Feminism in the United States got its start in the 1960s, but began to take flight starting in 1970, with the fiftieth anniversary of the passage of the Nineteenth Amendment to the United States Constitution (which legalized female suffrage). With the anthology Sisterhood is Powerful and other works being published at the start of the decade, feminism started to reach a larger audience.

Gay rights

The Stonewall riots, which occurred in New York City in June 1969, are generally considered to have ignited the modern gay rights movement, especially in North America (the U.K. had already decriminalised homosexuality in 1967). In the 1970s, in western countries and especially so in major urban centers, gay and lesbian people came out of the closet as never before (even as many others remained closeted) and a vocal and visible gay-rights movement coalesced in an unprecedented way. Considering the profound stigma attached to homosexuality at the dawn of the 1970s, the movement, although still nascent, saw tremendous gains over the course of the decade. The American Psychiatric Association removed homosexuality from its list of psychiatric disorders in 1973. Gay-rights ordinances were passed by several cities (beginning with Ann Arbor, Michigan in 1972), and, for the first time, a few openly gay people were elected to political office in the United States. In 1977 Harvey Milk, a politically active gay man in the emerging gay neighborhood The Castro, was elected to the Board of Supervisors in San Francisco. Milk and liberal San Francisco mayor George Moscone were assassinated the following year; in 1979 their assassin, Dan White, received a sentence of voluntary manslaughter. The anger the gay community felt about the murders and about White's light sentence further galvanized the movement. The increasing visibility of gay people also generated a backlash during the seventies. In perhaps the most discussed anti-gay rights campaign of the decade, singer Anita Bryant led a successful drive in 1977 to repeal a gay-rights ordinance in Dade County, Florida. The new openness about homosexuality proved disconcerting to some heterosexuals who had been accustomed to gay and lesbian people remaining closeted and politically silent. "The love that dare not speak its name," Canadian author Robertson Davies wrote during the decade, referencing the famous Lord Alfred Douglas quote, "has become the love that won't shut up." On October 14, 1979, approximately 100,000 people marched in Washington, D.C., in the largest pro-gay rights demonstration up to that time.

Culture during the Seventies

Emerging social perspectives in the Seventies

In the wake of the 1960s many of the social dimenisions and perspectives towards issues were increasingly seen in liberal perspectives. Universities became more friendly and less authoritative towards students. This was reflected in the corporate culture of the 1970s, where the hierarchy between supervisor and subordinates became increasingly flat. This had influence in social interaction and family relationship as well. The nuclear family rose to prominence in the third world and the role of women in nuclear families took radical shift from those of earlier generations. With the rise of nuclear family and liberal attitudes towards social structure came new perspectives to child rearing and education. The 70s saw a decline in attendance to boarding schools and a rise of local day schools. The role of the nuclear family and the parent was increasingly noticed and given new impetus. Social norms and laws were increasingly framed in favour of women.

The Seventies in music

The seventies were a time when a new generation of young people were exposed to new media and hence newer ideas in almost every field. Elvis was probably the biggest entertainer in the world in the 70´s and in 1973 he held the historic Hawaain concert which was televised worldwide to almost 1.5 billion people from over 40 countries. TV and motion picture brought to varied audiences images, lifestyles and music from diverse regions and peoples. This led to the emergence of a new vocabulary and experimentation in music. After the war the second generation of German musicians began experimenting with music, these included experimental classical music and the tradition of Krautrock or Kraut music, rooted in the experimental classical music. This later influenced both art rock and progressive rock. The main exponents of this genre include Genesis, Yes, Emerson, Lake & Palmer and space rock giants Pink Floyd. The experimental nature of progressive rock is exemplified in songs such as Pink Floyd's Echoes. The seventies is also when many legendary rock bands started, or hit their peak, including The Rolling Stones, Led Zeppelin, Aerosmith, AC/DC,Queen (Band),Black Sabbath]], KISS, The Who, and Van Halen. Another experimentation in European classical music was brought about by composer Philip Glass and Michael Nyman, with what was to be called Minimalist music. This was a break from the intellectual serial music of the tradition of Schoenberg which lasted from the early 1900s to 1960s. Minimalist music sought to appreciate simple music with systematic patterns repeated in complex variations. These experimentations were also used in several movies made in the early 1970s. In world music the musical collaboration of violinists Yehudi Menuhin and L. Subramaniam was appreciated by a large audience. The commercial cinemas around the world tended to imitate nuances of disco beats in their movies to present their movies as western and upbeat. These included the increasingly popular Kung-fu movies in far East Asia and Bollywood movies from India. One of the most successful European groups of the decade was the quartet ABBA. The Swedish group, who are still the most successful group from their country, first found fame when they won the 1974 Eurovision Song Contest. They became one of the most widely known European groups ever, and were the decade's biggest sellers. "Waterloo" and "Dancing Queen" are two of ABBA's most popular songs. To many people, the Seventies will be most remembered for the rise in disco music. First creeping into dance clubs in the mid-seventies (with such hits as "The Hustle" by Van McCoy), songstresses like Donna Summer, Gloria Gaynor, Dalida and Anita Ward popularized the genre and were described in subsequent decades as the "disco divas." The Village People scored a Top Ten hit with "Y.M.C.A." and the Bee Gees had a string of #1s following their collaboration on the Saturday Night Fever soundtrack. As quickly as disco's popularity came, however, it fell out of favor with the new decade, and effectively died in 1981, with the popularity of New Wave bands such as Blondie and Devo, who both formed their respective bands in the seventies. Many of the aforementioned singers who became popular during the disco era found themselves out of tune with the 1980s, and were out of work for many years, until a renewed interest in disco brought many of them back to the forefront. Many songs from the disco era are still very popular dance hits and receive continuous airplay in nightclubs throughout the world. The mid-seventies saw the rise of punk music from its protopunk/garage band roots in the 1960s and early 1970s. The Ramones, the Sex Pistols, and The Clash were some of the earliest acts to make it big in both the United Kingdom and the United States. Groups like the Clash were noted for the experimentation of style, especially that of having strong reggae influences in their music. Punk music has also been heavily associated with a certain punk fashion and absurdist humor which exemplified a genuine suspicion of mainstream culture and values.

The Seventies in cinema

World cinema

In cinema all over the world, the seventies brought about vigour in adventurous and realistic complex narratives with rich cinematography and elaborate scores. The cultural interaction between aided with TV and visual media and the rise in motion picture technology ushered in a new period of motion picture making. In European cinema, the failure of the Prague Spring brought about nostalgic motion pictures reminiscent of the ones that celebrate the 1970s itself. These movies expressed a yearning and as a premonition to the decade and its dreams. The Hungarian director István Szabó made the motion picture Szerelmesfilm (1970), which is a nostalgic portrayal and a premonition of the fading of the young 1970s ethos of change and a friendlier social structure. The Italian director Bernardo Bertolucci made the motion picture The Conformist (1970). German movies after the war aksed existential questions especially the works of Rainer Fassbinder. The movies of the Swedish director Ingmar Bergman reached a new level of expression in motion pictures like Cries and Whispers (1973). Young German directors made movies that came to be called as the German new wave. It was the voice of a new generation that had grown up after the second world war. These included directors like Wim Wenders, Hans-Jürgen Syberberg and Werner Herzog. Wim wenders made movies that explored psychological states of humans in situations intimate and significant to the characters. He made Die Angst des Tormanns beim Elfmeter (The Goalkeeper's Fear of the Penalty Kick) in 1972. It was based on a novella by Peter Handke. He further explored this realm in the motion picture Alice in den Städten (Alice in the Cities), 1974. Hans-Jürgen Syberberg created a sensation in 1977 with the motion picture Hitler: ein Film aus Deutschland (Hitler a film from Germany). It was a seven hour movie which attempted to investigate hitler under the shadows of wagner art and Nazi nationalism. This was followed by the expressionist movie Woyzeck (1979) by Werner Herzog. Asian cinema of the 1970s catered to the rising middle class fantasies and struggles. In the Bollywood cinema of India this was epitomised by the movies of Bollywood superhero Amitabh Bachchan. These movies portrayed adventurous plots with car chase trying to imitate hollywood movies like The French Connection, presented music with Disco beats and also presented the young middle class man as an "angry young man". The women on the other hand were shown as ones who have adopted western values and outfits especially by heroines like Parveen Babi (who was featured on the cover of TIME for a story on Bollywood's success) and Zeenat Aman. However towards the very end of the 1970s, especially after the steep rise in land prices in urban areas and the decline in employment security, the heroines were seen more often as saree-women striving to have a prosperous middle class family especially heroines like Jayaprada and Hema Malini. In this way the cinema of asian region becomes a sociological statement of the social-economic times of the region and its people. Other movie industry of the region produced fine masterpieces like in Malayalam cinema. Adoor Gopalakrishnan made Swayamvaram in 1972, which got wide critical acclaim. This was followed by the movie Nirmalyam by M.T. Vasudevan Nair in 1973.
Hollywood
The decade opened with Hollywood facing a financial slump, reflecting the monetary woes of the nation as a whole during the first half of the decade. Despite this, the seventies proved to be a benchmark decade in the development of cinema, both as an art form and a business. With young filmmakers taking greater risks and restrictions regarding language and sexuality lifting, Hollywood produced some its most critically acclaimed and financially successful films since its supposed "golden era." Hollywood for his role in the 1972 hit The Godfather. He boycotted the ceremony and sent Native American Sacheen Littlefeather to reject the award on his behalf. Also pictured are Roger Moore and Liv Ullmann.]] In the years previous to 1970, Hollywood had began to cater to the younger generation with films such as The Graduate and Topless Nurses. This proved a folly when anti-war films like R.P.M. and The Strawberry Statement became major box-office flops. Even solid films with bankable stars, like the Pearl Harbor epic Tora! Tora! Tora!, flopped, leaving studios in dire straights financially. Unable to repay financiers, studios began selling off land, furniture, clothing, and sets acquired over years of production. Nostalgic fans bid on merchandise and collectables ranging from Judy Garland's sparkling red shoes to MGM's own back lots. More of the successful films were those based in the harsh truths of war, rather than the excesses of the '60s. Films like Patton, about the World War II general, and M
- A
- S
- H, about a Korean War field hospital, were major box-office draws in 1970. Honest, old-fashioned films like Five Easy Pieces, Summer of '42, and the Erich Segal adaptation, Love Story, were commercial and critical hits. (Love Story and "Summer" remain, as of 2005, two of the most successful films in Hollywood history. "Summer," costing $1,000,000 USD, brought in $25,000,000 at the box office, while "Love Story," with a budget of $2,200,000, earned $106,400,000). One of the most insightful films of the decade came from the mind of a Hollywood outsider, Czechoslovakian director Milos Forman, whose Taking Off became a bold reflection of life at the beginning of the seventies. The 1971 satirized the American middle class, following a young girl who runs away from home, leaving her parents free to explore life for the first time in years. While the film was never given a wide release in America, it became a major critical achievement both in America and around the world (garnering the film high honors at the Cannes Film Festival and several BAFTA Award nominations). An adaptation of an Arthur Hailey novel would prove to be one of the most notable films of 1970, and would set the stage for a major trend in seventies cinema. The film, Airport, featured a complex plot, characters, and an all-star cast of Hollywood A-listers and legends. Airport followed an airport manager trying to keep a fictional Chicago airport operational during a blizzard, as well as a bomb plot to blow up an airplane. The film was a major critical and financial success, helping pull Universal Studios into the black for the year. The film earned senior actress Helen Hayes an Oscar for Best Supporting Actress and garnered many other nominations in both technical and talent categories. The success of the film launched a slew of disaster-related films, many of which following the same blueprint of major stars, a melodramatic script, and great suspense. disaster Three Airport sequels followed in 1974, 1977, and 1979, each successor making less money than the last. 1972 brought The Poseidon Adventure, which starred a young Gene Hackman leading an all-star cast to safety in a capsized luxury liner. The film earned an Academy Award for visual effects (and Best Original Song for "The Morning After," as well as numerous nominations, including one for its notable supporting star, Shelley Winters. The Towering Inferno teamed Steve McQueen and Paul Newman against a fire in a New York skyscraper. The film cost a whopping $14 million to produce (expensive for its time), and won Academy Awards for Cinematography, Film Editing, and Best Original Song. The same year, the epic Earthquake featured questionable effects (camera shake and models) to achieve a destructive 9.9 earthquake in Los Angeles. Despite this, the film was one of the most successful of its time, earning $80 million at box office. By the late seventies, the novelty had worn off and the disasters had become less exciting. 1977 brought a terrorist targeting a Rollercoaster, a 1978 Swarm of bees, and a less-than-threatening Meteor in 1979. 1971 brought a rebirth of the action film, three years after the influential Bullitt. The French Connection, starring Gene Hackman, brought suspense to new heights with an adrenaline-broiling car chase through the streets of New York City, while Get Carter featured gratuitous nudity and A Clockwork Orange featured much blood and gore to complement its complex story. African American filmmakers also found success in the seventies with such hits as Shaft and Sweet Sweetback's Baadasssss Song, and more questionable films, such as Blacula and Blackenstein. Like other sequels in the seventies, Shaft went on to have two more adventures, each less successful than the last. An adaptation of a Mario Puzo novel, The Godfather, became one of the best-loved and most respected works of cinema upon its release in 1972. The three-hour epic followed a Mafia boss, played by Marlon Brando, through his life of crime. Beyond the violence and drama were themes of love, pride, and greed. The Godfather went on to earn $134 million at American box office, and $245 million throughout the world. It won Academy Awards for Best Picture, Best Actor, and Best Screenplay. Its director Francis Ford Coppola was passed over in favor of Bob Fosse and his musical, Cabaret, which also earned an Oscar for its star, Liza Minnelli. The Godfather: Part II followed in 1974, with roughly the same principal cast and crew, earning Oscars for star Robert De Niro, its director, composer, screenwriters and art directors. The film also earned the Best Picture Oscar for that year. The replacement of Sean Connery, first with George Lazenby and then with Roger Moore, in the James Bond series created a minor bump for the '60s hit in the seventies. While 1973's Live and Let Die was a moderate success, the following films in the series didn't live up to expectations. The highest grossing of the seventies Bond films, 1979's Moonraker, is viewed by many as the weakest of the franchise. Other massively successful films would soon take Bond's place in the seventies. It was at this time that the blockbuster was born. While the 1973 horror classic The Exorcist was among the top five grossing films of the seventies, the first film given the blockbuster distinction was 1975's Jaws. Released on June 20th, the film about a series of horrific deaths related to a massive great white shark was director Steven Spielberg's first big-budget Hollywood production, coming in at a cool $9 million in cost. The film slowly grew in ticket sales and became one of the most profitable films of its