Jules Pascin and Internet Protocol: Difference between pages
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'''Julius Mordecai Pincas,''' (1885-1930) aka "''Pascin''", "The Prince of Montparnasse." |
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The '''Internet Protocol''' ('''IP''') is a [[network protocol]] that is the defining element of the [[Internet]] -- every connected [[host]] must understand it. IP is complemented by one or more lower-level protocols that deal with the particular network hardware (for example, an [[Ethernet]]), and one or more higher-level protocols that add functionality. |
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The whole collection of protocols is referred to as a [[protocol stack]]. |
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IP's designers believed strongly in layering: Every protocol has an explicit functionality, no more, no less. Additional features can be attained by putting another protocol layer on top of that. |
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Born '''Julius Mordecai Pincas''' in [[Vidin]], [[Bulgaria]] on [[March 31]], [[1885]], he would be known simply as "Pascin", but sometimes "Jules Pascin", after becoming part of the great migration of artistic creativity to [[Paris, France]] at the start of the 20th century. Arriving in December of 1905, Pascin, always in his bowler hat, became the symbol of the [[Montparnasse]] artistic community, his witty presence felt at the Dôme café, Le Jockey club, and the others haunts of the area’s [[bohemian]] society. In his story, "''A Moveable Feast''," Ernest Hemingway wrote a chapter titled: ''With Pascin At the Dôme''. |
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The main strength of IP is ''packet switching'': Transferring packets of data (called '''[[datagram]]s''' in IP parlance) from a source host to a destination host. In contrast to channel switched networks like the phone system, the Internet knows (on that level) nothing of connections. Each packet is [[router|routed]] independently; datagrams that have the same source and destination hosts -- and may as well belong to the same connection on a higher level -- could travel through the net on completely different paths. |
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During the 1920s, he began earning big money and he spent it all. Famous as the host of numerous large and raucous parties in his flat, whenever he was invited elsewhere for dinner, he arrived with as many bottles of wine as he could carry. In summers, he frequently led a large group of friends on picnics beside the [[River Marne]], their excursions lasting all afternoon. According to his biographer, Georges Charensol, "Scarcely had he chosen his table at the Dôme or the Sélect than he would be surrounded by five or six friends; at nine o'clock, when we got up to dinner, we would be 20 in all, and later in the evening, when we decided to go up to [[Montmartre]] to Charlotte Gardelle's or the Princess Marfa's - where Pascin loved to take the place of the drummer in the jazz band - he had to provide for 10 taxis." |
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A packet's journey consists of one or more '''[[hop]]s'''. The source host, and any intermediate points, decide where the best next stop for the packet would be, based on the destination address, the topology and state of nearby connections. Once the next stop is reached, this process begins anew, until the destination is reached, or a certain number of hops is exceeded. |
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During [[World War I]], Pascin lived in [[America]] and returned there briefly in 1927, obtaining American citizenship. |
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Similar to most protocols, IP divides its packets into an IP header (including a fixed part, followed by zero or more ''options''), and a [[payload]] of variable length, and arbitrary content. The chief features of the header are the already mentioned destination address, the source address, the protocol version, and the length of the packet (header plus payload). |
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Despite the constant partying, during his lifetime he created thousands of watercolors and sketches, plus drawings and caricatures that he sold to various newspapers and magazines. He studied the art of drawing at the Academy Colarossi and like his contemporary, [[Henri de Toulouse-Lautrec|Toulouse-Lautrec]], he drew upon his surroundings and his friends, both male and female, as the objects for his works. He wanted to become a serious painter but in time he became deeply depressed over his inability to achieve critical success with his efforts. |
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The IP in widespread use in [[2001]], and the one described here, is version 4, which was formalized in [[1978]] (IEN 41). The next generation is version 6. One major difference between versions is the number of addressable hosts. [[IPv4]] has enough address bits to distinguish 2<sup>32</sup> machines, while [[IPv6]] can accommodate 2<sup>128</sup>. Although there are far less than 2<sup>32</sup> (over 4 x 10<sup>9</sup>, that is to say, 4 US [[billion]]) connected hosts, packing them too densely produces increasingly complex routing issues -- so there is a mild push to migrate to version 6. So far, the use of [[classless inter-domain routing]] has helped preserve the IPv4 address space longer than expected, and its use is expected to continue with IPv6. |
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Suffering from depression and alcoholism, and "Driven to the wall by his own legend," said art critic Gaston Diehl, he committed suicide in his studio on [[June 5]], [[1930]]. On the wall he left a message written in his own blood that said good-bye to his lost love, Elvire "Lucy" Ventura. |
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A machine (other than a router) connected to the Internet typically has only one [[IP address]]. Because one often wants to run a number of services on the same host (for example, both a mail and a web server), most higher level protocols used in conjunction with IP define a [[multiplexing]] mechanism. The two most common protocols layered on top of IP, [[Transmission Control Protocol|TCP]] and [[User Datagram Protocol|UDP]] both use ''ports'' for this. In addition to multiplexing, TCP also offers reliability, and the notion of connections. |
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On the day of Pascin’s funeral, all the galleries in Paris closed. Thousands of acquaintances from the artistic community along with dozens of waiters and bartenders from the restaurants and saloons he had frequented, all dressed in black walked behind his coffin the three miles to the cemetery at [[Saint-Ouen]]. |
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IP spans the Transport and Network layers of the [[OSI model]]. |
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See also: [[TCP-IP|TCP/IP]] |
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Further reading: [http://www.ietf.org/rfc/rfc791.txt RFC791] |
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Revision as of 21:05, 24 December 2002
The Internet Protocol (IP) is a network protocol that is the defining element of the Internet -- every connected host must understand it. IP is complemented by one or more lower-level protocols that deal with the particular network hardware (for example, an Ethernet), and one or more higher-level protocols that add functionality. The whole collection of protocols is referred to as a protocol stack.
IP's designers believed strongly in layering: Every protocol has an explicit functionality, no more, no less. Additional features can be attained by putting another protocol layer on top of that.
The main strength of IP is packet switching: Transferring packets of data (called datagrams in IP parlance) from a source host to a destination host. In contrast to channel switched networks like the phone system, the Internet knows (on that level) nothing of connections. Each packet is routed independently; datagrams that have the same source and destination hosts -- and may as well belong to the same connection on a higher level -- could travel through the net on completely different paths.
A packet's journey consists of one or more hops. The source host, and any intermediate points, decide where the best next stop for the packet would be, based on the destination address, the topology and state of nearby connections. Once the next stop is reached, this process begins anew, until the destination is reached, or a certain number of hops is exceeded.
Similar to most protocols, IP divides its packets into an IP header (including a fixed part, followed by zero or more options), and a payload of variable length, and arbitrary content. The chief features of the header are the already mentioned destination address, the source address, the protocol version, and the length of the packet (header plus payload).
The IP in widespread use in 2001, and the one described here, is version 4, which was formalized in 1978 (IEN 41). The next generation is version 6. One major difference between versions is the number of addressable hosts. IPv4 has enough address bits to distinguish 232 machines, while IPv6 can accommodate 2128. Although there are far less than 232 (over 4 x 109, that is to say, 4 US billion) connected hosts, packing them too densely produces increasingly complex routing issues -- so there is a mild push to migrate to version 6. So far, the use of classless inter-domain routing has helped preserve the IPv4 address space longer than expected, and its use is expected to continue with IPv6.
A machine (other than a router) connected to the Internet typically has only one IP address. Because one often wants to run a number of services on the same host (for example, both a mail and a web server), most higher level protocols used in conjunction with IP define a multiplexing mechanism. The two most common protocols layered on top of IP, TCP and UDP both use ports for this. In addition to multiplexing, TCP also offers reliability, and the notion of connections.
IP spans the Transport and Network layers of the OSI model.
See also: TCP/IP
Further reading: RFC791