His Fathers Earth Essay Example

His Fathers Earth Essay John Moxley Mrs. Minton LNG 332 11 February 2010 Dreaming Before Succeeding At the age of four, Michael Jackson already knew he wanted to become a singer. Although Jackson did not know how he was going to achieve his goal, Jackson had the American dream on his side. In the short story, â€Å"His Father’s Earth† by Thomas Clayton Wolfe, Wolfe demonstrates how people have to dream before they can succeed through the main character. The main character is a young male, who in the story daydreams about joining the circus of the 1920s to achieve his goals of wealth and success (Wolfe). Wolfe exhibits how people have to believe in their dreams before they can succeed through the definition of the 1920s American dream, â€Å"His Father’s Earth,† and Wolfe’s own personal life. Wolfe published â€Å"His Father’s Earth† in 1925 during the roaring twenties. After World War I, America reinvented itself by the prohibition of alcohol. The prohibition of alcohol came into affect by the eighteenth amendment; the majority of Americans believed alcohol was destroying families and American values (Seth). The American dream of the 1920s was established upon organized crime like bootlegging. This fast money way of becoming rich was the norm of the 1920s (Seth). Like bootleggers, the main character in â€Å"His Father’s Earth, dreams about achieving wealth no matter how he has to do it. The majority of Americans during the 1920s would not think about using organized crime or joining the circus to become wealthy. Both the bootleggers and the young man used their dreams of wealth and success to rise above and obtain what they longed for (Wolfe). New money Americans put their social standards away to reach the unreachable. The American dream of the 1920s was an ideal goal that everyone hoped for and very few reached. We will write a custom essay sample on His Fathers Earth specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on His Fathers Earth specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on His Fathers Earth specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The dream changed from becoming a lawyer or a doctor, to being a gangster or a circus worker to achieve wealth and success. (Daniel). The circus of the 1920s was usually the most exciting event of small towns and cities. The circus began with a parade- colorfully dressed band members, a calliope piping its steam-whistle notes, wild animals roaring in rolling cages, elephants lumbering along in single file, and a wild array of clowns, acrobats and jugglers (Far and the Near). â€Å"His Father’s Earth† is a short story of a young male who in the story daydreams about running away and joining the profound circus (Wolfe). Numerous young Americans of the 1920s fantasized about running away to join the circus; it was the embodiment of fantasy and adventure (Far and the Near). The boy imagined himself joining the circus to sell tickets, put up posters, and barter with farmers for fresh food. Wolfe writes about the boy’s daydream to show that success does not come first without a dream (Wolfe). At the end of the story, Wolfe allows the reader to make a hypothesis that boy follows his dream of the circus, which would lead him to a successful American life. Thomas Wolfe was born in the smoky mountaintops of Ashville, North Carolina. Wolfe’s large family was not the wealthiest; he was very self-conscious of his family’s wealth, which made him an incredibly studious worker (Seth). At the age of sixteen, Wolfe entered the University of North Carolina at Chapel Hill through a scholarship to study literature. Wolfe’s vision was to become a successful playwright and an author (â€Å"Wolfe†). Wolfe’s first completed work was â€Å"Look Homeward, Angel† in 1928; the first draft filled up a suitcase of papers. After several publishers rejected his work and years of dreaming that his day would come, Wolfe finally got his first book published. Wolfe published a very small number of books before his sudden death in 1938. Wolfe died at thirty-eight years old, but before his death, Wolfe left many manuscripts that would later be published (Daniel). Thomas Wolfe’s life exhibits how an ordinary person can achieve his dreams no matter how rich or poor he is. Even though Wolfe died at an early age, Wolfe achieved his goals of being a playwright and an author through hard work. Thomas Wolfe demonstrates that success does not come before failure and that a person has to believe in his dream before he can succeed. Wolfe exhibits this idea through the definition of the 1920s American dream, His Father’s Earth, and Wolfe’s own personal life. Although Wolfe did not acclaim wealth or fame before his death, Wolfe placed his beliefs in the American society for eternity. Works Cited Benson, Frederick R. Wolfe, Thomas Clayton (1900-1938). Encyclopedia of World Biography. Ed. Suzanne M. Bourgoin. 2nd ed. Detroit: Gale Research, 1998. 17 vols. Discovering Collection. Gale. Web. 22 January 2010. Seth, John. â€Å"Thomas Clayton Wolfe. † 2005. Web. 20 January 2010. Daniel, Katyhleen, Richard, Sime, and Patricia McCambridge, eds. Elements of Literature. 5th ed. Austin: Holt-Rinehart-Winston, 1997. Print. â€Å"The Far and the Near. † Short Stories for Students. Vol. 18. Farmington Hills: Thomson Gale, 2003. 78-79. Print. Wolfe, Thomas (Clayton) (1900-1938). DISCovering Authors. Online ed. Detroit: Gale, 2003. Discovering Collection. Gale. Web. 20 January 2010. Wolfe, Thomas. â€Å"His Father’s Earth. † 1925. PDF File.

CSS Alabama - Civil War - Confederate Raider

CSS Alabama - Civil War - Confederate Raider Nation: Confederate States of AmericaType: Screw SteamerShipyard: John Laird Sons, BirkenheadLaid Down: 1862Launched: July 29, 1862Commissioned: August 24, 1862Fate: Sunk, June 19, 1864 CSS Alabama - Specifications Displacement: 1,050 tonsLength: 220 ft.Beam: 31 ft., 8 ft.Draft: 17 ft., 8 in.Speed: 13 knotsComplement: 145 men CSS Alabama - Armament Guns 6 x 32 lb. guns, 1 x 100 lb. Blakeley Rifle, 1 x 8 in. gun CSS Alabama - Construction Operating in England, Confederate agent James Bulloch was tasked with establishing contacts and finding vessels for the fledgling Confederate Navy. Establishing a relationship with Fraser, Trenholm Company, a respected shipping company, to facilitate the sale of Southern cotton, he was later able to use the firm as a front for his naval activities. As the British government remained officially neutral in the American Civil War, Bulloch was unable to purchase ships outright for military use. Working through Fraser, Trenholm Company, he was able to contract for the construction of a screw sloop at the yard of John Laird Sons Company in Birkenhead. Laid down in 1862, the new hull was designated #290 and launched on July 29, 1862. Initially named Enrica, the new ship was powered by a direct-acting, horizontal condensing steam engine with twin horizontal cylinders which powered a retractable propeller. In addition, Enrica was rigged as a three-masted barque and was capable of employing a large spread of canvas. As Enrica completed fitting out, Bulloch hired a civilian crew to sail the new vessel to Terceira in the Azores. Reaching the island, the ship was soon met by its new commander, Captain Raphael Semmes, and the supply vessel Agrippina which was carrying guns for Enrica. After Semmes arrival, work began to convert Enrica into a commerce raider. Over the next few days, sailors endeavored to mount the heavy guns which included six 32-pdr smoothbores as well as a 100-pdr Blakely Rifle and an 8-in. smoothbore. The latter two guns were placed on pivot mounts along the ships centerline. With the conversion complete, the ships moved into international waters off Terceira where Semmes officially commissioned the s hip into the Confederate Navy as CSS Alabama on August 24. CSS Alabama - Early Successes Though Semmes had sufficient officers to oversee the running of Alabama, he had no sailors. Addressing the crews of the attending ships, he offered them signing money, lucrative bonuses, as well as prize money if they signed on for a cruise of unknown length. Semmes efforts proved successful, and he was able to convince eighty-three sailors to join his ship. Electing to remain in the eastern Atlantic, Semmes departed Terceira and began stalking Union whaling ships in the area. On September 5, Alabama scored its first victim when it captured the whaler Ocumlgee in the western Azores. Burning the whaler the following morning, Alabama continued its operations with great success. Over the next two weeks, the raider destroyed a total of ten Union merchant ships, mostly whalers, and inflicted around $230,000 in damage. Turning west, Semmes sailed for the East Coast. After encountering poor weather en route, Alabama made its next captures on October 3 when it took the merchant ships Emily Farnum and Brilliant. While the former was released, the latter was burned. Over the next month, Semmes successfully took eleven more Union merchant ships as Alabama moved south along the coast. Of these, all were burned but two which were bonded and sent to port loaded with crewmen and civilians from Alabamas conquests. Though Semmes desired to raid New York Harbor, a lack of coal forced him to abandon this plan. Turning south, Semmes steamed for Martinique with the goal of meeting Agrippina and resupplying. Reaching the island, he learned that Union ships were aware of his presence. Sending the supply ship to Venezuela, Alabama was later forced slip past USS San Jacinto (6 guns) to escape. Re-coaling, Semmes sailed for Texas with the hope of frustrating Union operations off Galveston, TX. CSS Alabama - Defeat of USS Hatteras After pausing at Yucatan to conduct maintenance on Alabama, Semmes reached the vicinity of Galveston on January 11, 1863. Spotting the Union blockading force, Alabama was seen and approached by USS Hatteras (5). Turning to flee like a blockade runner, Semmes lured Hatteras away from its consorts before turning to attack. Closing on the Union sidewheeler, Alabama opened fire with its starboard broadside and in a quick thirteen-minute battle forced Hatteras to surrender. With the Union ship sinking, Semmes took the crew aboard and departed the area. Landing and paroling the Union prisoners, he turned south and made for Brazil. Operating along the coast of South America through late July, Alabama enjoyed a successful spell that saw it capture twenty-nine Union merchant ships. CSS Alabama - Indian Pacific Oceans In need of refit and with Union warships searching for him, Semmes sailed for Cape Town, South Africa. Arriving, Alabama spent part of August undergoing a badly-needed overhaul. While there, he commissioned one of his prizes, the bark Conrad, as CSS Tuscaloosa (2). While operating off South Africa, Semmes learned of the arrival of the powerful USS Vanderbilt (15) at Cape Town. After making two captures on September 17, Alabama turned east into the Indian Ocean. Passing through the Sunda Strait, the Confederate raider eluded USS Wyoming (6) before making three quick captures in early November. Finding hunting sparse, Semmes moved along the north coast of Borneo before overhauling his ship at Candore. Seeing little reason to remain in the area, Alabama turned west and arrived at Singapore on December 22. CSS Alabama - Difficult Circumstances Receiving a cool reception from British authorities in Singapore, Semmes soon departed. Despite Semmes best efforts, Alabama was in increasingly poor condition and badly needed dockyard refit. In addition, crew morale was low due to poor hunting in eastern waters. Understanding that these issues could only be resolved in Europe, he moved through the Straits of Malacca with the intention of reaching Britain or France. While in the straits, Alabama made three captures. The first of these, Martaban (formerly Texas Star) possessed British papers but had changed from American ownership only two weeks earlier. When Martabans captain failed to produce a sworn certificate stating that the papers were authentic, Semmes burned the ship. This action incensed the British and would ultimately force Semmes to sail for France. Re-crossing the Indian Ocean, Alabama departed Cape Town on March 25, 1864. Finding little in the way of Union shipping, Alabama made its final two captures in late April in the form of Rockingham and Tycoon. Though additional ships were sighted, the raiders fouled bottom and aging machinery allowed the potential prey to out-run the once-swift Alabama. Reaching Cherbourg on June 11, Semmes entered the harbor. This proved a poor choice as the only dry docks in the city belonged to the French Navy whereas La Havre possessed privately-owned facilities. Requesting use of the dry docks, Semmes was informed that it required the permission of Emperor Napoleon III who was on vacation. The situation was made worse by the fact that the Union ambassador in Paris immediately alerted all Union naval vessels in Europe as to Alabamas location. CSS Alabama - The Final Fight Among those who received word was Captain John A. Winslow of USS (7). Having been banished to a European command by Secretary of Navy Gideon Welles for making critical comments after the 1862 Second Battle of Manassas, Winslow quickly got his ship underway from the Scheldt and steamed south. Reaching Cherbourg on June 14, he entered the harbor and circled the Confederate ship before departing. Careful to respect French territorial waters, Winslow began patrolling outside of the harbor to prevent the raiders escape as well as prepared Kearsarge for battle by tricing chain cable over the vital areas of the ships sides. Unable to secure permission to use the dry docks, Semmes faced a difficult choice. The longer he remained in port, the greater the Union opposition would likely become and the chances increased that the French would prevent his departure. As a result, after issuing a challenge to Winslow, Semmes emerged with his ship on June 19. Escorted by the French ironclad frigate Couronne and the British yacht Deerhound, Semmes approached the limit of French territorial waters. Battered from its long cruise and with its store of powder in poor condition, Alabama entered the battle at a disadvantage. As the two vessels neared, Semmes opened fire first, while Winslow held Kearsarges guns until the ships were only 1,000 yards apart. As the fight continued, both ships sailed on circular courses seeking to gain an advantage over the other. Though Alabama hit the Union vessel several times, the poor condition of its powder showed as several shells, including one that hit Kearsarges sternpost, failed to detonate. Kearsarge faired better as its rounds hit with telling effect. An hour after the battle began, Kearsarges guns had reduced the Confederacys greatest raider to a burning wreck. With his ship sinking, Semmes struck his colors and requested help. Sending boats, Kearsarge managed to rescue much of Alabamas crew, though Semmes was able to escape aboard Deerhound. CSS Alabama - Aftermath The Confederacys top performing commerce raider, Alabama claimed sixty-five prizes which were valued at a total of $6 million. Hugely successful in disrupting Union commerce and inflating insurance rates, Alabamas cruise led to the use of additional raiders such as CSS Shenandoah. As many Confederate raiders, such as Alabama, CSS Florida, and Shenandoah, had been built in Britain with the British governments knowledge that the ships were destined for the Confederacy, the US Government pursued monetary damages after the war. Known as the Alabama Claims, the issue caused a diplomatic crisis that was finally resolved by the formation of a twelve-man committee which ultimately awarded damages of $15.5 million in 1872. Selected Sources CSS Alabama AssociationURI: CSS Alabama

Evaluation of a workplace learning environment(school) Essay

Evaluation of a workplace learning environment(school) - Essay Example Given this acknowledgement of the importance of workplace learning, I proceed by investigating the utility of learning theories in identifying barriers to such learning. Workplace learning has been defined as â€Å"learning or training undertaken in the workplace, usually on the job, including on-the-job training under normal operational conditions, and onsite training, which is conducted away from the work process (e.g. in a training room† (Australian National Training Authority, online). It critical to undertake workplace learning since it accords the key competencies needed by the school to stay competitive. How is a workplace ideal for learning envisioned? Smith & Hayton (1999, p. 252) puts forth that the school’s openness to change is a critical factor in the progress of training and development. They have also stated that there are external and moderating variables that influence training levels. The interplay among these factors is the key determinant to the kind of training which shall be prioritized by the firm (Ridoutt et al., 2002, p. 14). Moreover, it has also been presented that smaller-sized schools were more involved in informal training compared to larger ones. There are several drivers that affect and push training within any school, as follows: Approaches: Having pointed out this distinction, it may be worthwhile for me to delve more lengthily on learning processes which may be more applicable to the work setting, including action learning, situated learning, and incidental learning. Action learning is defined as a systematic way through which learning transpires by application of theory or by doing. It is anchored on the assumption that learning necessitates action and that this in turn needs input from learning. Learning per se is the expected result of action learning, and it does not intend to focus on the resolution of a problem (Lewis & Williams, 1994, p. 12). Brown et al (1988)

Transcending the Compulsion beyond the Counter Essay

Transcending the Compulsion beyond the Counter - Essay Example Its history and the way fast food chain of restaurants centering the military base since World War II metamorphosed a sleepy and quiet town into one of the most developed and busy townships of United States. With the sprawling employment, more and more interface of the teenagers was noticed in the fast food industry. Behind the Counter examines the effect of the involvement of the teenage folks readily into the growing fast food industry and its effect on the socio-cultural and socio-economic aspects of American society. Behind the Counter from Fast Food Nation: The Dark Side of the All-American Meal examines the effect of the â€Å"part-time† jobs and the involvement of the teenagers in the fast food industry. This essay intends to explore and examine the effect of the continuing legacy of the contemporary society of America as well. Behind the Counter is a very important and effective chapter that enables the readers to understand the subtleties and intricate relationships b etween economy, culture, and society. No one can ignore the tremendous power of economy on the development of culture and society and American society is not an exception in this regard. In this chapter, tracing the development and inception of a city which flourished holding the hands of the fast-food chain of restaurants examines how the teens are predominantly converted into the workforce that kept the fast food industry alive. Focusing on the working conditions of these teens, Schlosser also draws attention on the way these part-time jobs into the counters of the fast-food centers interfere in their education and explains the adverse effects of their spending of money.

Cause & Effect Essay over Crisis in America's Social Security System

Cause & Effect over Crisis in America's Social Security System - Essay Example The situation facing the social security is pretty clear. It has enough income to last for about thirty years, and it does not seem that it will be running out anytime soon. The program was created to provide benefits to the retired and old age people, and the benefits were said to rise with the growing increase in wages of the people. The fact that the economy is producing more than enough funds to offer an increasing standard of living for the future generations, while also honoring its commitment to the Social Security, comes as a shock to some people. As a matter of fact, the only threat that the social security is facing is from the politicians who are trying to ‘alter’ the system and bring drastic changes by faking a crisis. (The introduction to The changes that Bush wanted to bring would have actually put the Social Security System in crisis. His privatization plan would have half ruled half of the Social Security funds into private accounts. This would have made the Social Security dependent on the Trust Funds, which would have emptied the Trust Funds twenty years sooner, and as a result payments to the people would have reduced by seventy percent. This would have created a real crisis. The Social Security Trust Fund has been in operation for about seventy years. There was a much worse crisis in 1983. The Trust Fund was about to drain then, but the problem as brought under control, and it worked for over fifty years. The Social Security system has been altered a few times, to keep it stable. Even if the government just sits idle and does nothing, then the Trust Fund is said to run out in 2035. But even then the Social Security would not be broke. So the so called crisis said to have occurred, is not much of a threat. The Social Security is well established and is said to run effectively for the next many years. If it is threatened by anything, it is the ‘reforms’ of the politicians and their attacks on then system. Their

Internet Protocol Version 6 (IPv6) Analysis

Internet Protocol Version 6 (IPv6) Analysis Overview Internet Protocol version 6 (IPv6) is the next generation of protocol defined by InternetEngineering Task force (IETF) to replace the exiting IPv4 protocol. At present, the majority of Internet users are still using IPv4 protocol, and given that most of current networking applications and network equipment run in IPv4 environments, the migration from IPv4 to IPv6 cant be accomplished overnight. It is predictable that the migration will be a long-term process (it is forecasted that the process will take 10 20 years). During the migration, IPv4 and IPv6 will coexist in a same network. This migration process poses new challenges on the routers that are the core equipment in IP network. Traditional routers cant accommodate new future network with IPv4/v6 coexistence. The routers must be improved and upgraded so that they can support both IPv4 and IPv6.Given that the core router is very important and carries huge Internet traffics, it must be able to support IPv6 forwarding at wire rate. It means ASIC chip, but not software is used to support IPv6 packet processing. At the same time, it is very important that this support cant sacrifice any IPv4 performance. After all, most of current traffics is IPv4. The core router must expand to support IPv6 routing tables and needs to support IPv6 routing protocols, such as BGP4+, OSPFv3, ISISv6, RIPng and etc. It needs to support some migration strategy from IPv4 to IPv6, such as Tunnel, Dual Stack, Translation and etc. Same as many network technologies, successful deployment of IPv6 relies on the deployment of the operators IPv6 network. As one core component in IPv6 network, IPv6 core router is key to network building, applications, performance and stability. At present, mainstream router vendors like Cisco and Juniper announce that their routers can support IPv6 while some traditional IT equipment manufactures, especially those in Japan, think Internet upgrade caused by IPv6 will change the whole landscape of router market, which brings significant opportunities for them to enter router market. From 2000 to 2002, Hitachi, NEC and Fujitsu announced IPv6-capable core router to gain some market share in new Internet network. It must be admitted that IPv6 is still in the initial phase at present, which is reflected in the following aspects: most IPv6 network is in trial phase, the number of access users is low, carried IPv6 traffics cant be comparable to IPv4, the interoperability between IPv6 equipment still needs to be proved, and network engineers lack in experience in large-scale deployment and operation of IPv6 network. The lack of data and experience is one of important causes that make some operators lack in confidence in IPv6 network deployment. Many operators take wait-and-see attitudes. In order to prove IPv6 router (especially IPv6 core router), the support to IPv6, how are they performed and interoperated, provide a practical data basis for the operators to deploy IPv6 network and provide a reference for equipment manufactures to evaluate and improve their equipment, BII(Beijing Internet Institute) collaborate with 6TNet (IPv6 Telecom Trial Network) in China tested IPv6 core routers from 4 ven dors (Fujitsu, Hitachi, Juniper and NEC) in Beijing from October to December 2002. BII performed protocol conformance, performance and  interoperability tests. In these tests, we used the test instruments provided by Agilent and received strong technical support from Agilent. The test is not a comparative performance test in different router vendors. The purpose is to verify the feasibility of IPv6 deployment. With this test, the test team thinks that all SUT (system under test) has the ability to support commercial IPv6 network and provide basic IPv6 capabilities. They can support IPv6 routing protocols, support the forwarding of IPv6 datagram at wire rate and provide interoperability between them. From perspectives of pure technology, the test team thinks the products have been ready to deploy basic IPv6 core network.. Brief Descriptions of Test The requirements for hardware provided by the SUT (system under test) are as follows: IPv6-capable core router OC48 SM ports (both ports must be in different boards) Supports both FE ports and GE ports. The number of FE ports and GE ports is no less than 3 Finally, all vendors basically meet those requirements, although CX5210 provided by NEC doesnt support FE during the time of testing. The requirement for IPv6 capabilities provided by the SUT (system under test) include: support of IPv6 forwarding in hardware and support of related IPv6 routing protocols and migration strategy. Finally, all vendors meet our requirements as shown in the following table. Company IPv6 hardwareDual Stack RIPng OSPFv3 BGP4+ IPv6 over IPv4 forwarding Tunnel Fujitsu 9 9 9 9 9 9 Hitachi 9 9 9 9 9 9 Juniper 9 9 9 9 9 9 NEC 9 9 9 9 9 9 The SUT (system under test) models and OS versions are shown in the following table. Company Model Version Fujitsu Geostream R920 E10V02L03C44 Hitachi GR2000-20H S-9181-61 07-01 [ROUTE-OS6] Juniper M20 5.5R1.2 NEC CX5210 02.0(2e) 45.08.00 The test instruments we used in the test are as follows: Agilent Router Tester 900 Version: Router Tester 5.1,Build 11.15. Agilent QA Robot Version: Router Tester 5.3,Build 5.2 The IPv6 core router test is composed of three parts: Protocol conformance test, interoperability test and IPv6 performance test. Basic IPv6 Protocols and RIPng Basic IPv6 protocols include IPv6 Specification (RFC2460), ICMPv6 (RFC2463), Neighbor Discovery (RFC2461), Stateless Autoconfiguration (RFC2462), Path MTU Discovery (RFC1981), IPv6 address Architecture (RFC1884) and etc., which are basic capabilities provided by an IPv6 implementation. RIPng is defined by RFC2080 and is the extension and expansion of RIPv2. Its basic capabilities are same as RIPv2. The routing information exchanged by RIPng can carry IPv6 addresses and prefixes. RIPng runs on IPv6 network, uses multicasting address ff02::9 as destination to transfer routing information. RIPng is not compatible with RIPv2. RIP protocol is typically used in small networks and is not deployed in large networks because of its scalability and performance, which is same in IPv6 networks. The test does not include basic IPv6 protocols and RIPng because we think both capabilities are most basic and most preliminary capabilities that should be provided in an IPv6 router, these capabilities are implemented and interoperated very well in the routers from 4 vendors, and the 4 tested routers have been tested publicly or non-publicly several times in different occasions and provided good data. Therefore, we think it is unnecessary to make efforts to repeat these work and we skipped this test and focused on more challenged test items. BGP4+ Protocol Conformance Test At present, the external gateway protocol used in the IPv4 network is BGP4. Its basic protocols are defined in RFC1771. In order to carry IPv6 network information in BGP4 updates, IETF has defined a special property multi-protocol BGP (MP-BGP), also called IPv6 NLRI (Network Layer Reachability Information) to exchange IPv6 routing information, which is not a new version of BGP protocol, but an extension to BGP4. The extension is generally called BGP4+, which is compatible with BGP4. Refer to RFC2545 for its definition. Test Purpose and Used Standards: Purpose: To test the implementation of BGP4+ and conform with related standards for SUT (System Under Test). The following standards are referred in the test: Bates, T., Chandra, R., Katz, D. and Y. Rekhter, â€Å"Multiprotocol Extension for BGP-4†, RFC 2858, Jne 2000. Bates, T., Chandra, R., Chen, E., â€Å"BGP Route Reflection An Alternative to Full Mesh IBGP†, RFC2796, April 2000. Chandra, R. and J.Scudder, â€Å"Capabilities Advertisement with BGP-4†, RFC 2842, May 2000. Dupont, F. and P. Marques, â€Å"Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing†, RFC 2545, March 1999. Rekhter, Y. and T. Li, â€Å"A Border Gateway Protocol 4 (BGP-4) †. Traina, P., McPherson, D., Scudder, J., â€Å"Autonomous System Confederations for BGP†, RFC3065, February 2001. Test Methods: All the tests are based on topology emulation. One test port of instrument firstly establishes network topology emulation, then executes pre-written scripts, interacts with the port of SUT, performs related BGP4+ protocol tests individually and each test generates Passed/Failed record. The tests can be divided into active tests and passive tests. Active test means the tester is used to verify the state machine of SUT and the correctness of message format while passive test means the tester is used to interfere with SUT using messages with errors. Test Topology Test instrument and SUT use two independent Fast Ethernet or Gigabit Ethernet connections. All BGP4+ runs on the Fast Ethernet or Gigabit Ethernet connections. The physical topology is as follows: The logical topology is as follows: Test Items and Descriptions of Test Results: The BGP4+ protocol conformance test involves in the BGP multi-protocol extension, setup and transfer of BGP4+ IBGP and EBGP sessions, ability to receive IPv6 route updates, BGP4+ next hop, starting point, MED, local preference, AS_PATH, atom aggregation, community name and various properties, the ability of SUT to correctly process these properties, BGP4+ route reflector capability, BGP4+ federation capability. These tests can only ensure implementation of BGP4+protocol in SUT comply with the standard defined by RFC, and cant ensure SUT fully and successfully deploy BGP4+ routes in commercial IPv6 network. The following diagram briefly describes the test results. Attached table 1 includes all test items, description and detailed results of BGP4+ conformance tests for 4 routers. The test items and descriptions are extracted from RFC2858, RFC2545, RFC2842, RFC2796, RFC3065 and draft-ietf-idr-bgp4-14.txt part. Model Failed test items Fujitsu GeoStream R920 2 Hitachi GR2000-20H 5 Juniper M20 1 NEC CX5210 3 Analysis of Test Results: Capabilities not supported Confederation Route reflector, Community Fujitsus GeoStreamR920 of current version does not support BGP4+ federation capability. In all BGP4+ test items it supported, the general performance is fairly good. What needs to be improved is only one item that is to support the migration of undefined property and handle interim duration. It is hoped to improve null interface which cant support next hop at present. Hitachis GR2000-20H of current version supports all test items, and is only product fully supporting BGP4+ protocols in the core routers from 3 Japanese companies. However, it needs to be improved in the following areas: handling next-hop property of IBGP in BGP4+ protocol, using AS_PATH properties to prevent from route loop, the ability of route reflector to detect ORIGINATOR_ID. At the same time, we found in the interoperability test that GR2000-20H cant establish non-physical direct-connection sessions with IBGP peering entities, which Hitachi needs to improve. It is hoped to add loopback address capability. Junipers M20 passes all tests except one item excellently. NECs CX5210 of current version doesnt support BGP4+ route reflector and community properties. In all BGP4+ test items it supported, the general performance is fairly good. However, it needs to be improved in handling BGP4+ federation AS_CONFED_SEQUENCE property. It is hoped to add null interface configuration. Interoperability Test As above mentioned, IPv6 is in initial phase of commercial deployment at present. A large amount of IPv6-capable network equipments and terminals are available. IPv6 network built by the operators doesnt only use the equipment provided by a vendor. In multi-vendor network environment, the interoperability between equipment is vital. The interoperability test is composed of BGP4+ interoperability test and OSPFv3 interoperability test. It should be noted that specific items in the interoperability test only cover some most common properties of BGP4+ and OSPFv3, and are not the interoperability tests of all properties of BGP4+ and OSPFv3. BGP4+ Interoperability Establish IBGP Sessions Test Descriptions: The test is to verify GR2000-20H, CX5210, R920,M20 and fully meshed iBGP connections that can be established. Reference: RFC1771, RFC2545 and RFC2858. Test steps: GR2000-20H, CX5210, R920, M20 and SUT are connected as shown in the following diagram. 4 routers are in a same autonomous domain and are interconnected using IBGP protocol to form a full-meshed IBGP connection. Test instrument and SUT are interconnected using EBGP connection. Because GR2000-20H doesnt support IBGP across-router Session connection, we use a FE link to connect GR2000-20H to M20 to form a fully-meshed connection. Test Results: We verified whether iBGP sessions were established between GR2000-20H, CX5210, R920 and M20, and it was found all connections were set up successfully. GR2000-20H CX5210 R920 M20 GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A EBGP- Route Advertisement Test Descriptions: To verify GR2000-20H, CX5210, R920 and M20 can advertise routes properly in a fully meshed networks. References: RFC1771, RFC2545 and RFC2858. Test steps: Establish network topology according to previous test, establish eBGP connection between tester and SUT, send 100 EBGP routes from tester to SUT. Results: We verified whether GR2000-20H, CX5210 and R920 and M20 routing tables were correct, and it was found all routing tables were correct. GR2000-20H CX5210 R920 M20 GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A Establish EBGP Sessions Test Descriptions: The test is to verify GR2000-20H, CX5210, R920 and M20 can establish a fully meshed eBGP connections. Reference: RFC1771, RFC2545 and RFC2858. Test steps: GR2000-20H, CX5210, R920 and M20 are connected as shown in the following diagram. Test Descriptions: We verified whether EBGP sessions were established between GR2000-20H, CX5210, R920 and M20, and it was found all connections were established successfully. GR2000-20H CX5210 R920 M20 GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A EBGP Route Advertisement Test Descriptions: To verify GR2000-20H, CX5210, R920 and M20 can advertise EBGP routes properly. References: RFC1771, RFC2545 and RFC2858. Test steps: Establish network topology according to previous tests, send routes from each router to all other routers. Test Results: We verified whether GR2000-20H, CX5210 and R920 and M20 routing tables were correct, and it was found all routing tables were correct. GR2000-20H CX5210 R920, M20r GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A OSPFv3 Interoperability OSPF protocols supporting IPv6 is OSPFv3. OSPFv3 routing mechanism is basically same as OSPFv2. However, OSPFv2 relies primarily on IPv4, while OSPFv3 makes many improvements in OSPFv2 and is not a simple extension, thus OSPFv3, whose corresponding protocol is RFC2740, runs on IPv6. For real world applications, many operators regard OSPFv3 as a brand new protocol, also its stability and maturity need to be further verified, so when IPv6 routing protocols are selected, it tends to use IS-ISv6 (draft-ietf-isis-ipv6-02.txt), which is only a simple extension to IS-ISv4 (RFC1195) (2 TLVs re-defined) and does not make changes fully. However, it is sure the opinion is not authoritative and need to be proved. Because of the limitations of test instrument, It is required for SUT to provide 100M Ethernet interface. As CX5210 does not support Ethernet interface at present, just M20, R920 and GR2000-20H were involved in the testing. However, it does not imply that CX5210 cant interoperate with other 3 routers and has any problems with functions implementation. In the test, GR2000-20H is called SUT1 in short, M20 is called SUT2, and R920 is called SUT3. Establish OSPF Connections DR Election Test Descriptions: In the initial status, set different OSPF priority levels for SUT1, SUT2, SUT3 and the test instrument (10, 8, 5, 0). Connect these equipments based on the network topology below. Verify SUT1, SUT2, SUT3 and test instrument to establish OSPFv3 adjacency and vote DR/BDR. After DR/BDR is established properly, put DR off the network, and check whether DR/BDR is established properly. Put off-net equipment on the network, and check whether DR/BDR is established properly. Change OSPF initialization priorities of SUT1, SUT2, SUT3 and test instrument, and implement new test from step 2. Repeat the tests for 4 times, and ensure each SUT and test instrument have one opportunity to be selected as DR and BDR under the intial status. During the test, all SUTs are in the same OSPF Area 0. Reference: RFC2740 Test Results: During the testing, all the OSPF adjacencys can be established between SUTs and DR, also BDR can be elected properly. After DR is off-line, BDR can be re-elected as DR and the one with sub-top priority will be BDR. When off-line equipment is on-line again, no re-electing process occurs. All test results comply with the requirements in related standards. Exchange LSA Database Test Descriptions: Test instrument simulates an internal network with 4 routers connected, and sends the routing information to SUT. Then verify the routing information received by SUT DR from test instruments will be sent to DR Other correctly. Same as the previous test item, firstly SUT1 is used as DR, then SUT2, and finally SUT3. Reference: RFC2740 Test Results: During the testing, OSPF adjacency can be established properly between all SUTs. DR receive LSA information from test instrument and properly send the information to DR Other, which can also receive and process LSA information properly. IPv6 Performance Test The major approach used for the performance testing was to send the IPv6 traffic with different packet sizes and specific QoS information, via SUT to the destination, and then by the tester measure the throughput, latency and packet loss of SUT in various topologies. For the IPv6 performance test, there are four vendors high-end IPv6 routers, with OC-48 POS ports on which throughput and latency will be measured, with IPv6 packet sizes of 64 bytes, 128bytes, 256 bytes, 512 bytes, 1024 bytes, 1480 bytes and 1500 bytes. The performance in various of circumstances were measured, including IPv4/IPv6 mixed traffics (IPv4 and IPv6 traffics with different ratio), IPv6 traffic with packet sizes mixtures, Sweep Packet Sizes. Also the maximum routing table entry supported and the performance on manually configured tunnels were verified. Most of the referred standards is extracted from RFC2544. At present, there are deficient applications for IPv6, and the number of users in the IPv6 network can not be compared to IPv4. The sum of maximum IPv6 of IX(Internet eXchage) traffics is less than dozens of Mbits/s. These traffics can be handled using a router refitted from a PC. Based on the circumstance, is it necessary to test the performance of OC48 ports ? Actually when the operators build IPv6 network and purchase IPv6 routers, todays IPv6 network is not under their consideration. Their networks should be able to deal with the changes and growth of IPv6 network next 5 7 years. In this sense, it is necessary for IPv6 core router to support the IPv6 traffic forwarding capacities at wire rate. Otherwise, what differences can be made between a real IPv6 router and a router refitted from a PC with installed BSD and Zebra ? The measurement of the number of routing table entry also meets the same situations. At present, therere around 300-400 entries in the IPv6 backbone router routing table, which cant compared to the huge number of IPv4 (110,000 ¼Ã‚ 130,000 routes). Secondly, IPv6 has drawn experience and lessons from IPv4 in design and address assignment. RIR only assigns the large block and fixed length IPv6 addresses to IPv6 operators, instead of the end users. To some extent, this can protect IPv6 routing tables from the explosive growth. The strict prefix filtering mechanism was set on BGP4+ routers by most of IPv6 network administrators and the router only allows minor prefixes, such as /16, /24, /28, /32, /35 and etc. However, the experience of IPv4 teach us a lesson- â€Å"Money Talks!†. In the fiercely competitive ages, it is very difficult for operators to reject users requirements. Under the conditions that IPv6 doesnt solve the problems of Multi-homing completely, it is possible that the network operators are required to broadcast users network prefixes into global IPv6 routing tables in order to achieve Multi-homing applications. So far RIR has begun to assign /48 ad dress segment to IPv6 of IX independently, while it is suggested IX doesnt broadcast the addresses. Thirdly, in many IPv6 networks, there are at least two IPv6 addresses segments, from 6BONE(3ffe::/16) and RIR(2001::/16) respectively, and maybe more prefixes will appear in the future. Fourthly, RIR cant ensure IPV6 addresses assigned to IPv6 operators are from a continuous address block. Current assignment policy indicates that /32 addresses of IPv6 assigned to operators can be continuously extended to /29. If new addresses are further required, they must be assigned to discontinuous address blocks and result in the growth of the number of routing tables. To sum up, the test team suggests that the number of IPv6 routing tables supported by the router should be no less than that of IPv4 routing tables, since it is very difficult to estimate the increasing number of routing tables of IPv6 core network right now. In current IPv6 networks, commercial IPv6 network and IPv6 trial network (6BONE) are interlaced without a explicit boundary between them. A packet from commercial IPv6 network may go through many IPv6 trial network before arriving at another IPv6 network. The network administrators of many trial networks are not regarded as a â€Å"operators†, but a â€Å"players† It is pretty unstable of their networks, with routers reset very frequently. In the meantime, the networks advertise global IPv6 routes to all peers, making their own IPv6 network to implement transit. It causes the instability of current IPv6 of BGP routes, and thus it is required the capabilities of IPv6 routers cover the flapping and convergence properly, which should be included in this test, however due to limited test time frame, it is a pity the test team has to give up these tests. The network topology used for the performance test is shown as following: Ideally, the test topology should be as following, so that the packet forwarding capability of the routers in real-world network environment is shown completely. Send one traffic from a source port of the tester, via multiple ports of the router to the destination ports of tester, measure the performance of the router. However as the vendors cant provide enough OC48 ports, the test team can only perform the test by simply sending packets from one port and receiving packets form another port. In this sense, this test environment cant simulate completely the performance of the router in the real-world network environment. The Measurement of Throughput and Latency with Different IPv6 Packets Sizes at OC-48 POS port Test Descriptions: To test the maximum IPv6 packet forwarding rate of SUT with zero packet loss with different IPv6 packet sizes. Test Methods: Send IPv6 packets, via SUT to the destination ports of the tester, which measures the packet rate of SUT according to the received IPv6 packets. Set the initial offered load to 2%, and If no packet loss occurs, increase the offered load to 100% and repeat the test. If packet loss occurs, decrease the offered load to (100%+2%)/2=51%, repeat the test again†¦Ã¢â‚¬ ¦In a binary search manner, continue to increase or decrease the offered load in subsequent iterations until the difference in offered load between successful and failed tests is less than the resolution for the test. This is the zero-loss throughput rate. Traffic forwarding mode: full duplex. Offered Packet type: IPv6; Offered Packet size (bytes): 64 128 256 512 1024 1480 1500 Test duration of each packet type(s): 5 Bandwidth resolution (%): 0.1 Line BER tolerance (10^_): -10 The results are as follows: Sustainable Throughput of OC-48 POS Port 105.00% 100.00% 95.00% 90.00% 85.00% 80.00% 75.00% 70.00% 65.00% 60.00% 55.00% 50.00% 64 128 256 512 1024 1480 1500 bytes bytes bytes bytes bytes bytes bytes Test Packets Size Average Latency (us) at Variable Test Packets Size 100 90 80 70 60 50 40 30 20 10 0 Test Packets Size Hitachi NEC Fujistu Juniper Hitachi NEC Fujistu Juniper Note: About inherent latency of tester Before we perform tests, we must consider intrinsic latency of tester. The following table indicates inherent latency of tester for different test packet sizes when sending 100% offered load. Inherent latency of tester (100% offered load) Packet Size (bytes) 64 128 256 512 1024 1480 1500 Average Inherent 2.74 2.69 2.69 2.65 2.65 2.60 2.60 Latency (us) From the above, the inherent latency of tester under different packet sizes is about 2.7us. Compared to the tens of us of SUTs latency, there are not significant impacts on the test results. In addition, the impact of inherent latency is fair to these 4 SUTs. Forwarding Performance of IPv4/IPv6 Packets on OC48 Ports Test Descriptions: To verify the performance of SUT to forward IPv4/IPv6 packets in offered packets sizes. The test requires SUT to support IPv4/IPv6 dual protocol stacks. Test Methods: The tester sends IPv4 and IPv6 traffic simultaneously in full duplex configuration, via SUT to the destination port, measure the throughput and latency with various ratio of IPv4 and IPv6 traffic. Send traffic with 50% of IPv4 and 50% of IPv6 and 100% offered load first time. If packet loss occurs, decrease the offered load in 5% resolution until the difference in offered load between successful and failed tests is less than the resolution for the test. This is the zero-loss throughput rate. At the same time, measure the latency at maximum forwarding rate. Then change the ratio of IPv4 and IPv6 traffic to test again. Increase continuously the proportion of IPv6 traffic to simulate the change of traffic characteristics in the real-world network transition. Test Descriptions: Offered load (%): initial100% with 5% increment and final 0 Offered packet types: IPv6 Percentage of IPv4 and IPv6 traffic: 50:50—10:90 (IPv4:IPv6) Offered packet size (bytes): 62 512 1518 Test duration of each packet size(s): 5 The test results are as follows: Sustainable throughput of OC-48 POS port at packet size 64 bytes with different percentage of IPv4 and IPv6 traffic Sustainable Throughput of OC-48 POS Port at Packet Size 64 bytes with different Percentage of IPv4 and IPv6 Traffic 105% 100% 95% 90% 85% Hitachi 80% NEC 75% Fujistu 70% Juniper 65% 60% 55% 50% 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Sustainable throughput of OC-48 POS port at packet size 512 bytes with different percentage of IPv4 and IPv6 traffic Sustainable Throughput of OC-48 POS Port at Packet Size 512 bytes with different Percentage of IPv4 and IPv6 Traffic 105% 100% 95% 90% 85% Hitachi 80% NEC 75% Fujistu 70% Juniper 65% 60% 55% 50% 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Sustainable throughput of OC-48 POS port at packet size 1518 bytes with different percentage of IPv4 and IPv6 traffic Sustainable Throughput of OC-48 POS Port at Packet Size 1518 bytes with different Percentage of IPv4 and IPv6 Traffic 105% 100% 95% 90% 85% Hitachi 80% NEC 75% Fujistu 70% Juniper 65% 60% 55% 50% 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Average latency (us) at test packets size 64 bytes with different percentage of IPv4 and IPv6 traffic Average Latency (us) at Test Packets Size 64 bytes with Different Percentage of IPv4 and IPv6 Traffic 100 90 80 70 60 50 40 30 20 10 0 50/50 40/6 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Hitachi NEC Fujistu Juniper Average latency (us) at test packets size 512 bytes with different percentage of IPv4 and IPv6 traffic Average Latency (us) at Test Packets Size 512 bytes with Different Percentage of IPv4 and IPv6 Traffic 100 90 80 70 60 50 40 30 20 10 0 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Hitachi NEC Fujistu Juniper Average latency (us) at test packets size 1518 bytes with different percentage of IPv4 and IPv6 traffic Average Latency (us) at Test Packets Size 1518 bytes with Different Percentage of IPv4 and IPv6 Traffic 100 90 80 70 60 50 40 30 20 10 0 50/50 40/60 30/70 20/80  Ã‚  Ã‚  Ã‚   10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Hitachi NEC Fujistu Juniper IPv6 over IPv4 Configured Tunneling Performance of OC-48 POS Port Test Description: Tunneling technology is an effective means to connect separate IPv6 networks via IPv4 backbone. This item is to verify the performance of SUT when SUT encapsulates IPv6 data packets into IPv4 payload and forwards the packets. Test Method: The tester sends IPv6 data packets to SUT, and configures an IPv6 over IPv4 tunnel between SUT and the tester. Thus after SUT receives pure IPv6 packets from the tester, it will encapsulate it into IPv4 packet payload, and send IPv6 packets to destination over IPv4 network. The tester analyzes the packets forwared by the SUT at receiving end, calculates the throughput of SUT for different sizes of packets under the IPv6 over IPv4 configured tunnel. Test Results: IPv6 packet size: 512 Destination address of sending IPv6 data packets: 3FFE:0:0:4::2/64 Bandwidth range of sending IPv6 tra Internet Protocol Version 6 (IPv6) Analysis Internet Protocol Version 6 (IPv6) Analysis Overview Internet Protocol version 6 (IPv6) is the next generation of protocol defined by InternetEngineering Task force (IETF) to replace the exiting IPv4 protocol. At present, the majority of Internet users are still using IPv4 protocol, and given that most of current networking applications and network equipment run in IPv4 environments, the migration from IPv4 to IPv6 cant be accomplished overnight. It is predictable that the migration will be a long-term process (it is forecasted that the process will take 10 20 years). During the migration, IPv4 and IPv6 will coexist in a same network. This migration process poses new challenges on the routers that are the core equipment in IP network. Traditional routers cant accommodate new future network with IPv4/v6 coexistence. The routers must be improved and upgraded so that they can support both IPv4 and IPv6.Given that the core router is very important and carries huge Internet traffics, it must be able to support IPv6 forwarding at wire rate. It means ASIC chip, but not software is used to support IPv6 packet processing. At the same time, it is very important that this support cant sacrifice any IPv4 performance. After all, most of current traffics is IPv4. The core router must expand to support IPv6 routing tables and needs to support IPv6 routing protocols, such as BGP4+, OSPFv3, ISISv6, RIPng and etc. It needs to support some migration strategy from IPv4 to IPv6, such as Tunnel, Dual Stack, Translation and etc. Same as many network technologies, successful deployment of IPv6 relies on the deployment of the operators IPv6 network. As one core component in IPv6 network, IPv6 core router is key to network building, applications, performance and stability. At present, mainstream router vendors like Cisco and Juniper announce that their routers can support IPv6 while some traditional IT equipment manufactures, especially those in Japan, think Internet upgrade caused by IPv6 will change the whole landscape of router market, which brings significant opportunities for them to enter router market. From 2000 to 2002, Hitachi, NEC and Fujitsu announced IPv6-capable core router to gain some market share in new Internet network. It must be admitted that IPv6 is still in the initial phase at present, which is reflected in the following aspects: most IPv6 network is in trial phase, the number of access users is low, carried IPv6 traffics cant be comparable to IPv4, the interoperability between IPv6 equipment still needs to be proved, and network engineers lack in experience in large-scale deployment and operation of IPv6 network. The lack of data and experience is one of important causes that make some operators lack in confidence in IPv6 network deployment. Many operators take wait-and-see attitudes. In order to prove IPv6 router (especially IPv6 core router), the support to IPv6, how are they performed and interoperated, provide a practical data basis for the operators to deploy IPv6 network and provide a reference for equipment manufactures to evaluate and improve their equipment, BII(Beijing Internet Institute) collaborate with 6TNet (IPv6 Telecom Trial Network) in China tested IPv6 core routers from 4 ven dors (Fujitsu, Hitachi, Juniper and NEC) in Beijing from October to December 2002. BII performed protocol conformance, performance and  interoperability tests. In these tests, we used the test instruments provided by Agilent and received strong technical support from Agilent. The test is not a comparative performance test in different router vendors. The purpose is to verify the feasibility of IPv6 deployment. With this test, the test team thinks that all SUT (system under test) has the ability to support commercial IPv6 network and provide basic IPv6 capabilities. They can support IPv6 routing protocols, support the forwarding of IPv6 datagram at wire rate and provide interoperability between them. From perspectives of pure technology, the test team thinks the products have been ready to deploy basic IPv6 core network.. Brief Descriptions of Test The requirements for hardware provided by the SUT (system under test) are as follows: IPv6-capable core router OC48 SM ports (both ports must be in different boards) Supports both FE ports and GE ports. The number of FE ports and GE ports is no less than 3 Finally, all vendors basically meet those requirements, although CX5210 provided by NEC doesnt support FE during the time of testing. The requirement for IPv6 capabilities provided by the SUT (system under test) include: support of IPv6 forwarding in hardware and support of related IPv6 routing protocols and migration strategy. Finally, all vendors meet our requirements as shown in the following table. Company IPv6 hardwareDual Stack RIPng OSPFv3 BGP4+ IPv6 over IPv4 forwarding Tunnel Fujitsu 9 9 9 9 9 9 Hitachi 9 9 9 9 9 9 Juniper 9 9 9 9 9 9 NEC 9 9 9 9 9 9 The SUT (system under test) models and OS versions are shown in the following table. Company Model Version Fujitsu Geostream R920 E10V02L03C44 Hitachi GR2000-20H S-9181-61 07-01 [ROUTE-OS6] Juniper M20 5.5R1.2 NEC CX5210 02.0(2e) 45.08.00 The test instruments we used in the test are as follows: Agilent Router Tester 900 Version: Router Tester 5.1,Build 11.15. Agilent QA Robot Version: Router Tester 5.3,Build 5.2 The IPv6 core router test is composed of three parts: Protocol conformance test, interoperability test and IPv6 performance test. Basic IPv6 Protocols and RIPng Basic IPv6 protocols include IPv6 Specification (RFC2460), ICMPv6 (RFC2463), Neighbor Discovery (RFC2461), Stateless Autoconfiguration (RFC2462), Path MTU Discovery (RFC1981), IPv6 address Architecture (RFC1884) and etc., which are basic capabilities provided by an IPv6 implementation. RIPng is defined by RFC2080 and is the extension and expansion of RIPv2. Its basic capabilities are same as RIPv2. The routing information exchanged by RIPng can carry IPv6 addresses and prefixes. RIPng runs on IPv6 network, uses multicasting address ff02::9 as destination to transfer routing information. RIPng is not compatible with RIPv2. RIP protocol is typically used in small networks and is not deployed in large networks because of its scalability and performance, which is same in IPv6 networks. The test does not include basic IPv6 protocols and RIPng because we think both capabilities are most basic and most preliminary capabilities that should be provided in an IPv6 router, these capabilities are implemented and interoperated very well in the routers from 4 vendors, and the 4 tested routers have been tested publicly or non-publicly several times in different occasions and provided good data. Therefore, we think it is unnecessary to make efforts to repeat these work and we skipped this test and focused on more challenged test items. BGP4+ Protocol Conformance Test At present, the external gateway protocol used in the IPv4 network is BGP4. Its basic protocols are defined in RFC1771. In order to carry IPv6 network information in BGP4 updates, IETF has defined a special property multi-protocol BGP (MP-BGP), also called IPv6 NLRI (Network Layer Reachability Information) to exchange IPv6 routing information, which is not a new version of BGP protocol, but an extension to BGP4. The extension is generally called BGP4+, which is compatible with BGP4. Refer to RFC2545 for its definition. Test Purpose and Used Standards: Purpose: To test the implementation of BGP4+ and conform with related standards for SUT (System Under Test). The following standards are referred in the test: Bates, T., Chandra, R., Katz, D. and Y. Rekhter, â€Å"Multiprotocol Extension for BGP-4†, RFC 2858, Jne 2000. Bates, T., Chandra, R., Chen, E., â€Å"BGP Route Reflection An Alternative to Full Mesh IBGP†, RFC2796, April 2000. Chandra, R. and J.Scudder, â€Å"Capabilities Advertisement with BGP-4†, RFC 2842, May 2000. Dupont, F. and P. Marques, â€Å"Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing†, RFC 2545, March 1999. Rekhter, Y. and T. Li, â€Å"A Border Gateway Protocol 4 (BGP-4) †. Traina, P., McPherson, D., Scudder, J., â€Å"Autonomous System Confederations for BGP†, RFC3065, February 2001. Test Methods: All the tests are based on topology emulation. One test port of instrument firstly establishes network topology emulation, then executes pre-written scripts, interacts with the port of SUT, performs related BGP4+ protocol tests individually and each test generates Passed/Failed record. The tests can be divided into active tests and passive tests. Active test means the tester is used to verify the state machine of SUT and the correctness of message format while passive test means the tester is used to interfere with SUT using messages with errors. Test Topology Test instrument and SUT use two independent Fast Ethernet or Gigabit Ethernet connections. All BGP4+ runs on the Fast Ethernet or Gigabit Ethernet connections. The physical topology is as follows: The logical topology is as follows: Test Items and Descriptions of Test Results: The BGP4+ protocol conformance test involves in the BGP multi-protocol extension, setup and transfer of BGP4+ IBGP and EBGP sessions, ability to receive IPv6 route updates, BGP4+ next hop, starting point, MED, local preference, AS_PATH, atom aggregation, community name and various properties, the ability of SUT to correctly process these properties, BGP4+ route reflector capability, BGP4+ federation capability. These tests can only ensure implementation of BGP4+protocol in SUT comply with the standard defined by RFC, and cant ensure SUT fully and successfully deploy BGP4+ routes in commercial IPv6 network. The following diagram briefly describes the test results. Attached table 1 includes all test items, description and detailed results of BGP4+ conformance tests for 4 routers. The test items and descriptions are extracted from RFC2858, RFC2545, RFC2842, RFC2796, RFC3065 and draft-ietf-idr-bgp4-14.txt part. Model Failed test items Fujitsu GeoStream R920 2 Hitachi GR2000-20H 5 Juniper M20 1 NEC CX5210 3 Analysis of Test Results: Capabilities not supported Confederation Route reflector, Community Fujitsus GeoStreamR920 of current version does not support BGP4+ federation capability. In all BGP4+ test items it supported, the general performance is fairly good. What needs to be improved is only one item that is to support the migration of undefined property and handle interim duration. It is hoped to improve null interface which cant support next hop at present. Hitachis GR2000-20H of current version supports all test items, and is only product fully supporting BGP4+ protocols in the core routers from 3 Japanese companies. However, it needs to be improved in the following areas: handling next-hop property of IBGP in BGP4+ protocol, using AS_PATH properties to prevent from route loop, the ability of route reflector to detect ORIGINATOR_ID. At the same time, we found in the interoperability test that GR2000-20H cant establish non-physical direct-connection sessions with IBGP peering entities, which Hitachi needs to improve. It is hoped to add loopback address capability. Junipers M20 passes all tests except one item excellently. NECs CX5210 of current version doesnt support BGP4+ route reflector and community properties. In all BGP4+ test items it supported, the general performance is fairly good. However, it needs to be improved in handling BGP4+ federation AS_CONFED_SEQUENCE property. It is hoped to add null interface configuration. Interoperability Test As above mentioned, IPv6 is in initial phase of commercial deployment at present. A large amount of IPv6-capable network equipments and terminals are available. IPv6 network built by the operators doesnt only use the equipment provided by a vendor. In multi-vendor network environment, the interoperability between equipment is vital. The interoperability test is composed of BGP4+ interoperability test and OSPFv3 interoperability test. It should be noted that specific items in the interoperability test only cover some most common properties of BGP4+ and OSPFv3, and are not the interoperability tests of all properties of BGP4+ and OSPFv3. BGP4+ Interoperability Establish IBGP Sessions Test Descriptions: The test is to verify GR2000-20H, CX5210, R920,M20 and fully meshed iBGP connections that can be established. Reference: RFC1771, RFC2545 and RFC2858. Test steps: GR2000-20H, CX5210, R920, M20 and SUT are connected as shown in the following diagram. 4 routers are in a same autonomous domain and are interconnected using IBGP protocol to form a full-meshed IBGP connection. Test instrument and SUT are interconnected using EBGP connection. Because GR2000-20H doesnt support IBGP across-router Session connection, we use a FE link to connect GR2000-20H to M20 to form a fully-meshed connection. Test Results: We verified whether iBGP sessions were established between GR2000-20H, CX5210, R920 and M20, and it was found all connections were set up successfully. GR2000-20H CX5210 R920 M20 GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A EBGP- Route Advertisement Test Descriptions: To verify GR2000-20H, CX5210, R920 and M20 can advertise routes properly in a fully meshed networks. References: RFC1771, RFC2545 and RFC2858. Test steps: Establish network topology according to previous test, establish eBGP connection between tester and SUT, send 100 EBGP routes from tester to SUT. Results: We verified whether GR2000-20H, CX5210 and R920 and M20 routing tables were correct, and it was found all routing tables were correct. GR2000-20H CX5210 R920 M20 GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A Establish EBGP Sessions Test Descriptions: The test is to verify GR2000-20H, CX5210, R920 and M20 can establish a fully meshed eBGP connections. Reference: RFC1771, RFC2545 and RFC2858. Test steps: GR2000-20H, CX5210, R920 and M20 are connected as shown in the following diagram. Test Descriptions: We verified whether EBGP sessions were established between GR2000-20H, CX5210, R920 and M20, and it was found all connections were established successfully. GR2000-20H CX5210 R920 M20 GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A EBGP Route Advertisement Test Descriptions: To verify GR2000-20H, CX5210, R920 and M20 can advertise EBGP routes properly. References: RFC1771, RFC2545 and RFC2858. Test steps: Establish network topology according to previous tests, send routes from each router to all other routers. Test Results: We verified whether GR2000-20H, CX5210 and R920 and M20 routing tables were correct, and it was found all routing tables were correct. GR2000-20H CX5210 R920, M20r GR2000-20H N/A OK OK OK CX5210 OK N/A OK OK R920 OK OK N/A OK M20 OK OK OK N/A OSPFv3 Interoperability OSPF protocols supporting IPv6 is OSPFv3. OSPFv3 routing mechanism is basically same as OSPFv2. However, OSPFv2 relies primarily on IPv4, while OSPFv3 makes many improvements in OSPFv2 and is not a simple extension, thus OSPFv3, whose corresponding protocol is RFC2740, runs on IPv6. For real world applications, many operators regard OSPFv3 as a brand new protocol, also its stability and maturity need to be further verified, so when IPv6 routing protocols are selected, it tends to use IS-ISv6 (draft-ietf-isis-ipv6-02.txt), which is only a simple extension to IS-ISv4 (RFC1195) (2 TLVs re-defined) and does not make changes fully. However, it is sure the opinion is not authoritative and need to be proved. Because of the limitations of test instrument, It is required for SUT to provide 100M Ethernet interface. As CX5210 does not support Ethernet interface at present, just M20, R920 and GR2000-20H were involved in the testing. However, it does not imply that CX5210 cant interoperate with other 3 routers and has any problems with functions implementation. In the test, GR2000-20H is called SUT1 in short, M20 is called SUT2, and R920 is called SUT3. Establish OSPF Connections DR Election Test Descriptions: In the initial status, set different OSPF priority levels for SUT1, SUT2, SUT3 and the test instrument (10, 8, 5, 0). Connect these equipments based on the network topology below. Verify SUT1, SUT2, SUT3 and test instrument to establish OSPFv3 adjacency and vote DR/BDR. After DR/BDR is established properly, put DR off the network, and check whether DR/BDR is established properly. Put off-net equipment on the network, and check whether DR/BDR is established properly. Change OSPF initialization priorities of SUT1, SUT2, SUT3 and test instrument, and implement new test from step 2. Repeat the tests for 4 times, and ensure each SUT and test instrument have one opportunity to be selected as DR and BDR under the intial status. During the test, all SUTs are in the same OSPF Area 0. Reference: RFC2740 Test Results: During the testing, all the OSPF adjacencys can be established between SUTs and DR, also BDR can be elected properly. After DR is off-line, BDR can be re-elected as DR and the one with sub-top priority will be BDR. When off-line equipment is on-line again, no re-electing process occurs. All test results comply with the requirements in related standards. Exchange LSA Database Test Descriptions: Test instrument simulates an internal network with 4 routers connected, and sends the routing information to SUT. Then verify the routing information received by SUT DR from test instruments will be sent to DR Other correctly. Same as the previous test item, firstly SUT1 is used as DR, then SUT2, and finally SUT3. Reference: RFC2740 Test Results: During the testing, OSPF adjacency can be established properly between all SUTs. DR receive LSA information from test instrument and properly send the information to DR Other, which can also receive and process LSA information properly. IPv6 Performance Test The major approach used for the performance testing was to send the IPv6 traffic with different packet sizes and specific QoS information, via SUT to the destination, and then by the tester measure the throughput, latency and packet loss of SUT in various topologies. For the IPv6 performance test, there are four vendors high-end IPv6 routers, with OC-48 POS ports on which throughput and latency will be measured, with IPv6 packet sizes of 64 bytes, 128bytes, 256 bytes, 512 bytes, 1024 bytes, 1480 bytes and 1500 bytes. The performance in various of circumstances were measured, including IPv4/IPv6 mixed traffics (IPv4 and IPv6 traffics with different ratio), IPv6 traffic with packet sizes mixtures, Sweep Packet Sizes. Also the maximum routing table entry supported and the performance on manually configured tunnels were verified. Most of the referred standards is extracted from RFC2544. At present, there are deficient applications for IPv6, and the number of users in the IPv6 network can not be compared to IPv4. The sum of maximum IPv6 of IX(Internet eXchage) traffics is less than dozens of Mbits/s. These traffics can be handled using a router refitted from a PC. Based on the circumstance, is it necessary to test the performance of OC48 ports ? Actually when the operators build IPv6 network and purchase IPv6 routers, todays IPv6 network is not under their consideration. Their networks should be able to deal with the changes and growth of IPv6 network next 5 7 years. In this sense, it is necessary for IPv6 core router to support the IPv6 traffic forwarding capacities at wire rate. Otherwise, what differences can be made between a real IPv6 router and a router refitted from a PC with installed BSD and Zebra ? The measurement of the number of routing table entry also meets the same situations. At present, therere around 300-400 entries in the IPv6 backbone router routing table, which cant compared to the huge number of IPv4 (110,000 ¼Ã‚ 130,000 routes). Secondly, IPv6 has drawn experience and lessons from IPv4 in design and address assignment. RIR only assigns the large block and fixed length IPv6 addresses to IPv6 operators, instead of the end users. To some extent, this can protect IPv6 routing tables from the explosive growth. The strict prefix filtering mechanism was set on BGP4+ routers by most of IPv6 network administrators and the router only allows minor prefixes, such as /16, /24, /28, /32, /35 and etc. However, the experience of IPv4 teach us a lesson- â€Å"Money Talks!†. In the fiercely competitive ages, it is very difficult for operators to reject users requirements. Under the conditions that IPv6 doesnt solve the problems of Multi-homing completely, it is possible that the network operators are required to broadcast users network prefixes into global IPv6 routing tables in order to achieve Multi-homing applications. So far RIR has begun to assign /48 ad dress segment to IPv6 of IX independently, while it is suggested IX doesnt broadcast the addresses. Thirdly, in many IPv6 networks, there are at least two IPv6 addresses segments, from 6BONE(3ffe::/16) and RIR(2001::/16) respectively, and maybe more prefixes will appear in the future. Fourthly, RIR cant ensure IPV6 addresses assigned to IPv6 operators are from a continuous address block. Current assignment policy indicates that /32 addresses of IPv6 assigned to operators can be continuously extended to /29. If new addresses are further required, they must be assigned to discontinuous address blocks and result in the growth of the number of routing tables. To sum up, the test team suggests that the number of IPv6 routing tables supported by the router should be no less than that of IPv4 routing tables, since it is very difficult to estimate the increasing number of routing tables of IPv6 core network right now. In current IPv6 networks, commercial IPv6 network and IPv6 trial network (6BONE) are interlaced without a explicit boundary between them. A packet from commercial IPv6 network may go through many IPv6 trial network before arriving at another IPv6 network. The network administrators of many trial networks are not regarded as a â€Å"operators†, but a â€Å"players† It is pretty unstable of their networks, with routers reset very frequently. In the meantime, the networks advertise global IPv6 routes to all peers, making their own IPv6 network to implement transit. It causes the instability of current IPv6 of BGP routes, and thus it is required the capabilities of IPv6 routers cover the flapping and convergence properly, which should be included in this test, however due to limited test time frame, it is a pity the test team has to give up these tests. The network topology used for the performance test is shown as following: Ideally, the test topology should be as following, so that the packet forwarding capability of the routers in real-world network environment is shown completely. Send one traffic from a source port of the tester, via multiple ports of the router to the destination ports of tester, measure the performance of the router. However as the vendors cant provide enough OC48 ports, the test team can only perform the test by simply sending packets from one port and receiving packets form another port. In this sense, this test environment cant simulate completely the performance of the router in the real-world network environment. The Measurement of Throughput and Latency with Different IPv6 Packets Sizes at OC-48 POS port Test Descriptions: To test the maximum IPv6 packet forwarding rate of SUT with zero packet loss with different IPv6 packet sizes. Test Methods: Send IPv6 packets, via SUT to the destination ports of the tester, which measures the packet rate of SUT according to the received IPv6 packets. Set the initial offered load to 2%, and If no packet loss occurs, increase the offered load to 100% and repeat the test. If packet loss occurs, decrease the offered load to (100%+2%)/2=51%, repeat the test again†¦Ã¢â‚¬ ¦In a binary search manner, continue to increase or decrease the offered load in subsequent iterations until the difference in offered load between successful and failed tests is less than the resolution for the test. This is the zero-loss throughput rate. Traffic forwarding mode: full duplex. Offered Packet type: IPv6; Offered Packet size (bytes): 64 128 256 512 1024 1480 1500 Test duration of each packet type(s): 5 Bandwidth resolution (%): 0.1 Line BER tolerance (10^_): -10 The results are as follows: Sustainable Throughput of OC-48 POS Port 105.00% 100.00% 95.00% 90.00% 85.00% 80.00% 75.00% 70.00% 65.00% 60.00% 55.00% 50.00% 64 128 256 512 1024 1480 1500 bytes bytes bytes bytes bytes bytes bytes Test Packets Size Average Latency (us) at Variable Test Packets Size 100 90 80 70 60 50 40 30 20 10 0 Test Packets Size Hitachi NEC Fujistu Juniper Hitachi NEC Fujistu Juniper Note: About inherent latency of tester Before we perform tests, we must consider intrinsic latency of tester. The following table indicates inherent latency of tester for different test packet sizes when sending 100% offered load. Inherent latency of tester (100% offered load) Packet Size (bytes) 64 128 256 512 1024 1480 1500 Average Inherent 2.74 2.69 2.69 2.65 2.65 2.60 2.60 Latency (us) From the above, the inherent latency of tester under different packet sizes is about 2.7us. Compared to the tens of us of SUTs latency, there are not significant impacts on the test results. In addition, the impact of inherent latency is fair to these 4 SUTs. Forwarding Performance of IPv4/IPv6 Packets on OC48 Ports Test Descriptions: To verify the performance of SUT to forward IPv4/IPv6 packets in offered packets sizes. The test requires SUT to support IPv4/IPv6 dual protocol stacks. Test Methods: The tester sends IPv4 and IPv6 traffic simultaneously in full duplex configuration, via SUT to the destination port, measure the throughput and latency with various ratio of IPv4 and IPv6 traffic. Send traffic with 50% of IPv4 and 50% of IPv6 and 100% offered load first time. If packet loss occurs, decrease the offered load in 5% resolution until the difference in offered load between successful and failed tests is less than the resolution for the test. This is the zero-loss throughput rate. At the same time, measure the latency at maximum forwarding rate. Then change the ratio of IPv4 and IPv6 traffic to test again. Increase continuously the proportion of IPv6 traffic to simulate the change of traffic characteristics in the real-world network transition. Test Descriptions: Offered load (%): initial100% with 5% increment and final 0 Offered packet types: IPv6 Percentage of IPv4 and IPv6 traffic: 50:50—10:90 (IPv4:IPv6) Offered packet size (bytes): 62 512 1518 Test duration of each packet size(s): 5 The test results are as follows: Sustainable throughput of OC-48 POS port at packet size 64 bytes with different percentage of IPv4 and IPv6 traffic Sustainable Throughput of OC-48 POS Port at Packet Size 64 bytes with different Percentage of IPv4 and IPv6 Traffic 105% 100% 95% 90% 85% Hitachi 80% NEC 75% Fujistu 70% Juniper 65% 60% 55% 50% 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Sustainable throughput of OC-48 POS port at packet size 512 bytes with different percentage of IPv4 and IPv6 traffic Sustainable Throughput of OC-48 POS Port at Packet Size 512 bytes with different Percentage of IPv4 and IPv6 Traffic 105% 100% 95% 90% 85% Hitachi 80% NEC 75% Fujistu 70% Juniper 65% 60% 55% 50% 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Sustainable throughput of OC-48 POS port at packet size 1518 bytes with different percentage of IPv4 and IPv6 traffic Sustainable Throughput of OC-48 POS Port at Packet Size 1518 bytes with different Percentage of IPv4 and IPv6 Traffic 105% 100% 95% 90% 85% Hitachi 80% NEC 75% Fujistu 70% Juniper 65% 60% 55% 50% 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Average latency (us) at test packets size 64 bytes with different percentage of IPv4 and IPv6 traffic Average Latency (us) at Test Packets Size 64 bytes with Different Percentage of IPv4 and IPv6 Traffic 100 90 80 70 60 50 40 30 20 10 0 50/50 40/6 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Hitachi NEC Fujistu Juniper Average latency (us) at test packets size 512 bytes with different percentage of IPv4 and IPv6 traffic Average Latency (us) at Test Packets Size 512 bytes with Different Percentage of IPv4 and IPv6 Traffic 100 90 80 70 60 50 40 30 20 10 0 50/50 40/60 30/70 20/80 10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Hitachi NEC Fujistu Juniper Average latency (us) at test packets size 1518 bytes with different percentage of IPv4 and IPv6 traffic Average Latency (us) at Test Packets Size 1518 bytes with Different Percentage of IPv4 and IPv6 Traffic 100 90 80 70 60 50 40 30 20 10 0 50/50 40/60 30/70 20/80  Ã‚  Ã‚  Ã‚   10/90 IPv4/IPv6 Test Packets Percentage (IPv4/IPv6) Hitachi NEC Fujistu Juniper IPv6 over IPv4 Configured Tunneling Performance of OC-48 POS Port Test Description: Tunneling technology is an effective means to connect separate IPv6 networks via IPv4 backbone. This item is to verify the performance of SUT when SUT encapsulates IPv6 data packets into IPv4 payload and forwards the packets. Test Method: The tester sends IPv6 data packets to SUT, and configures an IPv6 over IPv4 tunnel between SUT and the tester. Thus after SUT receives pure IPv6 packets from the tester, it will encapsulate it into IPv4 packet payload, and send IPv6 packets to destination over IPv4 network. The tester analyzes the packets forwared by the SUT at receiving end, calculates the throughput of SUT for different sizes of packets under the IPv6 over IPv4 configured tunnel. Test Results: IPv6 packet size: 512 Destination address of sending IPv6 data packets: 3FFE:0:0:4::2/64 Bandwidth range of sending IPv6 tra

To Kill a Mockingbird by Harper Lee :: To Kill a Mockingbird Essays

A summary: When Scout was six, Dill (Charles Baker Harris) comes to visit his aunt and becomes good friends with the Finches. The children in Maycomb spend all their free time of summer trying to get Boo (Arthur) Radley come out of his house. None of the children have ever seen the mysterious man that lives next door, but they never find out that he is actually shut up in this house. After the summer is over, Scout enters school and gets into trouble because she already knows how to read and to write. She is always constantly getting into fights with boys like Walter Cunningham, the son of a poor farmer. During that year, Scout and her older brother Jem begin to find things in a hole in a tree on the Radley property as they pass it going to and from school. The next summer, Dill returns and the three continue their plans to make Boo Radley emerge from his house. They try to use a fishing pole to stick a note onto one of the windows of the Radleys. One night they decided to sneak up t o one of the windows to have a peek inside. Jem reaches the porch when a shadow appears and the three of them run for their lives just as a shotgun blast is heard. Jem gets caught on the fence by his pants so he has to slip out of them in order to escape. Later he tries to go get the pants that he lost and is afraid. A little bit later Scout hears that the pants were mended very strangely and lying on the fence. The next fall, the children make their first snowman. During this cold spell, Miss Maudie's house burns down and Scout and Jem have to stand outside for fear that their house might also burn down. While they are shivering in the cold, someone wraps a blanket around scout without their knowing it. All indications point to Boo Radley putting the blanket around her. About this time, the children begin to hear in the town that their father is a "nigger- lover." Atticus warns his children never to fight about this, but at Christmas time when one of Scout's cousins makes the same statement, she bloodies his nose. That Christmas, both children receive air rifles but they are given instructions that they must never kill a