Addressing and routing are the most complex aspects of IP. However, intelligence in the network is located at nodes (network interconnection points) in the form of routers which forward datagrams to the next known gateway on the route to the final destination. The routers use interior gateway protocols (IGPs) or external gateway protocols (EGPs) to help with making forwarding route decisions. Routes are determined by the routing prefix within the datagrams. The routing process can therefore become complex. But at the speed of light (or nearly so) the routing intelligence determines the best route, and the datagram pieces and datagram all eventually arrive at their destination
IP packets or datagram has two parts. The first part is the header, which is like a label on an envelope. The second part is the payload, which is like the letter inside an envelope. The header contains the source and destination IP addresses, and some extra information. This information is called metadata, and is about the packet itself. Putting data in a packet with a header is encapsulation.
Every computer on a network does some kind of routing. Dedicated computers talk with each other to figure out where to send packets. These computers are called routers, and talk using routing protocols.
Along every hop in a packet's journey, a computer reads the header. The computer sees the destination IP address and figures out where to send the packet.
ARPANET, the early ancestor of the internet, was designed to survive a nuclear war. If one computer was destroyed, communication between all the other computers would still work. Computer networks still follow this same design.
Computers talking to each other handle the "smart" functions to simplify computer networks. The end nodes will check for errors instead of a central authority. Keeping the "smart" things on the end computers or nodes follows the end-to-end principle.
The Internet Protocol sends packets out without ensuring they arrive safely. This is "best-effort delivery", and is unreliable. Packets could get messed up, lost, duplicated, or received out of order. Higher level protocols like the Transmission Control Protocol ("TCP") ensure packets are delivered correctly. IP is also "connectionless", so it does not keep track of communications.
Internet Protocol Version 4 (IPv4) uses a checksum to check for errors in an IP header. Every checksum is unique to a source/destination combination. A routing node generates a new checksum when it gets a packet. If the new checksum is different from the old one, the routing node knows the packet is bad and throws it out. IPv6 assumes another protocol will check for errors and leaves out the checksum. This is to improve performance.
In 1974, the Institute of Electrical and Electronics Engineers published a paper called "A Protocol for Packet Network Intercommunication". The paper described a way for computers to talk to each other using Packet Switching. A big part of this idea was the "Transmission Control Program". The Transmission Control Program was too big, so it split into TCP and IP. This model is now called the "DoD" "Internet Model" and "Internet Protocol Suite", or the TCP/IP Model.
Versions 0 to 3 of IP were experimental, and used between 1977 and 1979.
IPv4 addresses will run out, because the number of possible addresses is finite. To fix this, the IEEE made IPv6 which had even more addresses. While IPv4 has 4.3 Billion addresses, IPv6 has 340 undecillion of them. This means we will never run out of IPv6 addresses. IPv5 was reserved for the Internet Stream Protocol, which was only used experimentally.
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Akihito
Akihito became emperor after the death of his father in 1989, who was Emperor Shōwa. The current emperor's official reign name is "Heisei" (establishing peace).
The Japanese government announced in December 2017 that Akihito would abdicate on 30 April 2019. He then did so in a brief ceremony on that date.
The emperor has many duties and responsibilities. For example, he regularly
As a personal interest, Akihito studies fish.
Akihito directly addressed his subjects in a television broadcast after the 2011 Tōhoku earthquake and tsunami. This was the first time any emperor used television in this way.
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Aero Space Museum
The Aero Space Museum is an airplane museum in Calgary in Canada. The museum, founded in 1975, is near the Calgary Airport.
Some things at the museum are war-time airplanes: a Sopwith Triplane from World War I and an Avro Lancaster from World War II.
There are also peace-time airplanes made by Cessna and de Havilland, and a helicopter made by Sikorsky. The museum also has a large library of flying information available for people to read and look at.
Canadian Museum of Flight
The Canadian Museum of Flight is an aircraft museum at the Langley Airport in Langley, British Columbia, Canada. The museum has about 20 peace-time and war-time motor airplanes, gliders, and helicopters to see, six of which can still fly.
List of aircraft displayed :
Olympic Flight Museum
The Olympic Flight Museum is an aircraft museum at the Olympia Airport in Olympia, Washington, USA. The museum has more than 20 airplanes and helicopters to see, most of which can still fly.
San Diego Aerospace Museum
San Diego Aerospace Museum is an aircraft and space exploration museum in San Diego, California, USA. It contains many original and copies of old aircraft and spacecraft, including:
Pearson Air Museum
The Pearson Air Museum is an airplane museum at Pearson Field Airport in Vancouver, Washington, USA. The museum and Pearson Field, and the Fort Vancouver National Historic Site, are all part of the Vancouver National Historic Reserve.
The Pearson Air Museum shows different kinds of unusual, special, and historic airplanes. For example, an experimental and one-of-a-kind aircraft known as the "flying pickle" originally based at Watts Airport (or Bernard's Airport), is shown at the Pearson. Alley reports on this special airplane based at Watts Airport in 1929, that was an experimental one-of-a-kind model. In this aircraft the pilot sits in an open air compartment, behind a roomy enclosed passenger cabin.
Newfoundland and Labrador
Newfoundland and Labrador () is a province on the East Coast of Canada, and is the farthest east of all Canadian provinces and territories. The capital of Newfoundland and Labrador is St. John's. In 2016, 519,716 people lived in Newfoundland and Labrador.
Newfoundland is an island, while Labrador is within the mainland of Canada and on a border with Quebec.
The province of Newfoundland and Labrador was originally called Newfoundland and joined Canada in 1949, becoming the newest province of Canada, after being a colony of the United Kingdom. Until an agreement was reached in 1927, Quebec also claimed Labrador.
In 2001, the name of Newfoundland changed to its new official name, Newfoundland and Labrador, while the postal code abbreviation changed from NF to NL. The island of Newfoundland, and part of Labrador, are in a time zone that is a half hour off from any other part of North America.
Greenfinch
The greenfinch ("Chloris chloris"), also known as the European greenfinch, is a small passerine bird in the finch family Fringillidae.
This bird is widespread throughout Europe, north Africa and southwest Asia. It is mainly resident, but some northernmost populations migrate further south. The Greenfinch has also been introduced into both Australia and New Zealand.
Woodland edges, farmland hedges and gardens with relatively thick vegetation are favoured for breeding. It nests in trees or bushes, laying 38 eggs. This species can form large flocks outside the breeding season, sometimes mixing with other finches and buntings. They feed largely on seeds, but also take berries.
St. John's, Newfoundland and Labrador