【正文】
ing assumes an unusual importance. His “Wessex” villages cast intangibly such as spell upon the villagers that once they leave their hometowns they will inevitably suffer from disasters, and the farther they are away from their hometowns, the more, terrible their disasters will be. For example, in the Tess of the D’Urbervilles, the Vale of Blakemore was the place where Tess was born and her life was to unfold. Every contour of the surrounding hills was as personal to her as that of her relatives’ faces。 (4) the general environment of the characters, for example, religious, mental, moral, social, and emotional conditions through which characters in the story move. (Holman and Harman, A Handbook to literature, 1986) But often, in an effective story, setting may figure as more than mere background. It can make things happen. It can prompt characters to act, bring them to realizations, or cause them to reveal their innermost natures, as we shall see in John Cheever’s short story “The Swimmer”. (2) the occupations and daily manner of living of the characters。1. The elements making up a settingAn event occurs and a character exists in a particular time and place. This particular time and place is referred to as setting. A setting is the background against which a character is depicted or an event narrated. Its purpose is to provide an imaginary link between what happens in the novel and what the reader takes to be reality. Like some other elements, setting is not peculiar to the novel. The reader finds it serving the same purpose in different genres. The traditional way to tell a story reveals much about setting.This is the opening sentences of “Golden Touch”, which introduces the time, place, and the usual mentality of the character. Chapter Four SettingWhen we have worked our statement of theme, have we cast our statement into general language, not just given a plot summary? Does the author (through the narrator) make any general observations about life or human nature? Do the characters make any (Caution: Characters now and again will utter opinions with which the reader is not necessarily supposed to agree.)Look back once more at the title of the story. What does it indicate in relation to the whole story? When we say that the title of Pride and Prejudice conveys the theme of the novel or that Uncle Tom’s Cabin and The Grapes of Wrath treat the themes of slavery and migratory labor respectively, this is to use theme in a larger and more abstract sense than it is in our discussion of Hemingway’s “A Clean, WellLighted Place.” In this larger sense it is relatively easy to say that Mark Twain’s Huckleberry Finn, Updike’s A amp。 Moral inferences drawn from most stories:基于流分類的靈活QinQ實(shí)現(xiàn)機(jī)理如下:基于流的QinQ特性(Selected QinQ),可靈活根據(jù)流分類的結(jié)果選擇是否打外層VLAN tag、打上何種外層VLAN tag:如根據(jù)用戶Vlan tag、MAC地址、IP協(xié)議、源地址、目的地址、優(yōu)先級(jí)、或應(yīng)用程序的端口號(hào)等信息實(shí)施靈活QinQ特性。由于基于端口的QinQ比較容易實(shí)現(xiàn),所以業(yè)界主流廠家的三層交換機(jī)都支持?;诙丝诘腝inQ的實(shí)現(xiàn)機(jī)理如下:當(dāng)該設(shè)備端口接收到報(bào)文,無論報(bào)文是否帶有VLAN Tag,交換機(jī)都會(huì)為該報(bào)文打上本端口缺省VLAN的VLAN Tag。MPLS VPNs 提供與用戶內(nèi)部網(wǎng)的無縫集成。MPLS VPN 通過限制VPN 路由信息的傳播僅在VPN成員內(nèi)部,可提供與第二層VPN 相同的私密性及安全性?;贛PLS 的VPN具有以下優(yōu)勢(shì)。MPLSVPN即采用MPLS技術(shù),在公共IP網(wǎng)絡(luò)上構(gòu)建企業(yè)IP專網(wǎng),實(shí)現(xiàn)數(shù)據(jù)、語音、圖像多業(yè)務(wù)寬帶連接,并結(jié)合差別服務(wù)、流量工程等相關(guān)技術(shù),為用戶提供高質(zhì)量的服務(wù)。 在MPLS入口處的LER接收IP包,完成第三層功能,并給IP包加上標(biāo)簽;在MPLS出口處的LER將分組中的標(biāo)簽去掉后繼續(xù)進(jìn)行轉(zhuǎn)發(fā)。MPLS 結(jié)合了IP的靈活連接和可擴(kuò)展性,以及ATM的可靠傳輸和QOS。MPLS,不是特指某一種業(yè)務(wù)或應(yīng)用,而是一種標(biāo)準(zhǔn)化的路由與交換技術(shù)平臺(tái),可以支持各種高層協(xié)議與業(yè)務(wù),MPLS報(bào)文交換和轉(zhuǎn)發(fā)是基于標(biāo)簽的。MPLS VPN網(wǎng)絡(luò)中,有三種設(shè)備:CE、PE和P路由器,CE是用戶直接與服務(wù)提供商相連的邊緣設(shè)備,可以是路由器、交換機(jī)或者終端;PE是骨干網(wǎng)中的邊緣設(shè)備,它直接與用戶的CE相連;P 路由器是骨干網(wǎng)中不與CE直接相連的設(shè)備。MPLS VPN的網(wǎng)絡(luò)構(gòu)造由服務(wù)提供商來完成。 MPLS/VPNMPLS是多協(xié)議標(biāo)簽交換協(xié)議的簡(jiǎn)稱。隨著三網(wǎng)合一的推行,突破接入網(wǎng)瓶頸變得越來越迫切,只有突破接入部分的帶寬“瓶頸”,才能使整個(gè)網(wǎng)絡(luò)有效發(fā)揮寬帶的作用,真正推動(dòng)各種業(yè)務(wù)的發(fā)展。2 技術(shù)介紹隨著寬帶業(yè)務(wù)的發(fā)展,人們?cè)絹碓揭庾R(shí)到網(wǎng)絡(luò)的接入部分(最后1 km)存在嚴(yán)重的帶寬“瓶頸”。 可運(yùn)營(yíng)可管理 - 網(wǎng)絡(luò)應(yīng)提供良好的業(yè)務(wù)管理和靈活的控制能力;實(shí)現(xiàn)集中監(jiān)測(cè)、分權(quán)管理,實(shí)現(xiàn)統(tǒng)一的網(wǎng)絡(luò)業(yè)務(wù)調(diào)度和管理,降低網(wǎng)絡(luò)運(yùn)營(yíng)成本。 多業(yè)務(wù)支持能力強(qiáng) - 通過劃分邏輯平面,使網(wǎng)絡(luò)具備端到端的QoS保證能力,通過合理規(guī)劃,能滿足多業(yè)務(wù)承載的QoS要求。 高性能 - 設(shè)備處理能力、網(wǎng)絡(luò)帶寬及業(yè)務(wù)承載能力設(shè)計(jì)時(shí)應(yīng)有余量,保證網(wǎng)絡(luò)在高負(fù)荷或任何單點(diǎn)故障情況下仍具有較高的吞吐能力,不影響業(yè)務(wù)質(zhì)量。經(jīng)濟(jì)適用性的原則。就是要求網(wǎng)絡(luò)規(guī)劃要從技術(shù)角度保障方案實(shí)施的可行性。具體表現(xiàn)為以下的技術(shù)指標(biāo):A、核心層高性能、有效的數(shù)據(jù)轉(zhuǎn)發(fā);能夠承載普通上網(wǎng)業(yè)務(wù)、廣電內(nèi)部DCN業(yè)務(wù)以及未來3G、NGN等業(yè)務(wù);需要提供不同業(yè)務(wù)所需的QoS保證,以保證IPTV、NGN等應(yīng)用對(duì)QOS的嚴(yán)格要求;電信級(jí)的穩(wěn)定可靠性,具備自愈能力和快速的路由收斂;支持OSPF、ISIS、BGP,具備良好的路由轉(zhuǎn)發(fā)處理能力,支持大容量路由表,支持 Differsrv/MPLS QOS,支持MPLS VPN、組播等協(xié)議;提供兩個(gè)網(wǎng)絡(luò)出口連接到兩個(gè)ISP,實(shí)現(xiàn)城域網(wǎng)出口的備份;為各種增值業(yè)務(wù)和VPN提供單獨(dú)的城域網(wǎng)出口;B、匯聚層支持千兆上行,每個(gè)縣/區(qū)雙歸屬到核心層,保障業(yè)務(wù)的不間斷;為每個(gè)區(qū)/縣提供兩個(gè)連接到骨干網(wǎng)的出口,為普通業(yè)務(wù)和專線業(yè)務(wù)提供各自的出口,同時(shí)兩個(gè)出口互相備份;在每個(gè)區(qū)/縣的網(wǎng)絡(luò)出口,部署QOS,通過業(yè)務(wù)感知、業(yè)務(wù)標(biāo)識(shí),實(shí)現(xiàn)不同用戶或不同業(yè)務(wù),分流到不同的業(yè)務(wù)平面,提供不同的服務(wù)質(zhì)量保證;能夠支持接入層用戶靈活的接入方式,除了支持傳統(tǒng)的以太網(wǎng)接入外,還支持EPON、WLAN等方式的接入;C、接入層為每個(gè)最終用戶提供有足夠的帶寬,滿足寬帶上網(wǎng)和NGN等應(yīng)用;具有IP、VLAN、MAC、PORT綁定;入戶采用百兆速率;接入用戶的二層隔離;限速功能,可以為不同的用戶分配不同的帶寬;可以實(shí)現(xiàn)特殊用戶的VPN等需求。3) MPLS VPN業(yè)務(wù) 提供大客戶的專網(wǎng)接入,重點(diǎn)是跨地區(qū)的專網(wǎng)業(yè)務(wù)。初期目標(biāo)為10000戶增強(qiáng)型數(shù)字電視( VOD )用戶。在建網(wǎng)初期通過少量的投資和設(shè)備就可以提供完整的業(yè)務(wù)能力,并且隨著業(yè)務(wù)的發(fā)展,在保護(hù)原有投資的情況下,可以對(duì)網(wǎng)絡(luò)做平滑升級(jí),直至萬兆骨干城域網(wǎng)。 項(xiàng)目目標(biāo) 桐鄉(xiāng)IP城域網(wǎng)將根據(jù)桐鄉(xiāng)廣電臺(tái)對(duì)數(shù)字電視網(wǎng)絡(luò)建設(shè)的指導(dǎo)意見,充分參考杭州成熟的運(yùn)營(yíng)模式,建設(shè)一個(gè)高質(zhì)量、高可靠性、高擴(kuò)展性的多業(yè)務(wù)網(wǎng)絡(luò),網(wǎng)絡(luò)設(shè)計(jì)堅(jiān)持適度超前的原則,以滿足未來幾年桐鄉(xiāng)廣電對(duì)于業(yè)務(wù)的需求。城區(qū)由4個(gè)分前端(分別為:體育路機(jī)房、梧桐廣電站機(jī)房、銀菊機(jī)房、傳媒中心機(jī)房)組成,分別設(shè)置匯聚層交換機(jī),小區(qū)機(jī)房放置接入層交換機(jī)。 總體需求桐鄉(xiāng)廣電網(wǎng)絡(luò)基本需求:根據(jù)桐鄉(xiāng)市廣電的實(shí)際情況,本次工程將升級(jí)中心機(jī)房的核心路由交換機(jī)(現(xiàn)有的是CISCO6509),通過12條單模光纖連接12個(gè)鎮(zhèn)、街道廣電站的交換機(jī)(現(xiàn)有的是CISCO3550及CISCO2924),通過單模中距光纖連接到桐鄉(xiāng)市區(qū)各個(gè)分前端機(jī)房匯聚層交換機(jī),通過分前端機(jī)房再連接到小區(qū)機(jī)房接入層交換機(jī)。建設(shè)一個(gè)基于IP的高帶寬、高可靠性、可運(yùn)營(yíng)管理、具備多種業(yè)務(wù)綜合承載能力和擴(kuò)展性的電信級(jí)IP網(wǎng)絡(luò),將成為桐鄉(xiāng)廣電開展全業(yè)務(wù)運(yùn)營(yíng)的關(guān)鍵?;趶V電HFC 網(wǎng)絡(luò), 如何進(jìn)行網(wǎng)絡(luò)改造,順利過渡到下一代有線電視網(wǎng)絡(luò)(NGCN),逐步開展全新的數(shù)字電視業(yè)務(wù)以及豐富的增值業(yè)務(wù),是廣電行業(yè)面臨的巨大挑戰(zhàn)和歷史機(jī)遇。廣電IP城域網(wǎng)改造方案建議書廣電IP城域網(wǎng)改造方案建議書 廣電IP城域網(wǎng)改造方案建議書目錄1 項(xiàng)目概述 1 背景介紹 1 總體需求 1 項(xiàng)目目標(biāo) 2 網(wǎng)絡(luò)設(shè)計(jì)原則 32 技術(shù)介紹 5 MPLS/VPN 5 靈活QinQ技術(shù) 63 承載網(wǎng)整體方案建議 1 1 24 設(shè)備推薦及特性介紹 3 核心路由交換機(jī)S8508 3 匯聚交換機(jī)S5600 10 匯聚交換機(jī)S3900 19 接入交換機(jī)S2000 265 路由策略 31 路由設(shè)計(jì)原則 31 路由協(xié)議選擇 31 域間路由協(xié)議選擇 31 域內(nèi)路由協(xié)議選擇 32 組播路由協(xié)議選擇 326 寬帶接入運(yùn)營(yíng)管理建議 34 VLAN劃分 34 PUPSPV方式 34 PUPV方式 35 PSPV方式 35 混合方式 361 項(xiàng)目概述 背景介紹目前廣電行業(yè)正處于全國(guó)數(shù)字電視整體轉(zhuǎn)換的歷史時(shí)期,廣電運(yùn)營(yíng)商除了傳統(tǒng)廣播電視業(yè)務(wù)的運(yùn)營(yíng)外,對(duì)數(shù)字電視、語音通信、寬帶數(shù)據(jù)等多業(yè)務(wù)融合的有效支持,實(shí)現(xiàn)綜合性全業(yè)務(wù)運(yùn)營(yíng)已成為業(yè)界普遍認(rèn)同的趨勢(shì)。國(guó)家“十一五規(guī)劃”中明確提出了計(jì)算機(jī)網(wǎng)絡(luò)、通信網(wǎng)絡(luò)、廣電網(wǎng)絡(luò)實(shí)現(xiàn)“三網(wǎng)融合”的總體要求,近年來,下一代網(wǎng)絡(luò)也一直是業(yè)界談?wù)摰慕裹c(diǎn)。另一方面,根據(jù)桐鄉(xiāng)廣電寬帶城域網(wǎng)業(yè)務(wù)的發(fā)展和目前網(wǎng)絡(luò)運(yùn)營(yíng)模式的發(fā)展趨勢(shì),現(xiàn)有的城域業(yè)務(wù)網(wǎng)的承載和接入能力已經(jīng)不能滿足當(dāng)前市場(chǎng)的需求,急需進(jìn)行改造和擴(kuò)容。廣電實(shí)現(xiàn)網(wǎng)絡(luò)雙向改造是其業(yè)務(wù)發(fā)展必須經(jīng)過的技術(shù)門檻,實(shí)現(xiàn)網(wǎng)絡(luò)雙向改造的技術(shù)種類在一定時(shí)期內(nèi)會(huì)并存,但最終的發(fā)展方向是IP的方向,以太接入網(wǎng)是最完善的接入方式,EPON是目前廣電以太網(wǎng)建設(shè)的最佳起步方式;目前,華為是EPON技術(shù)的國(guó)內(nèi)領(lǐng)先者。在中心機(jī)房設(shè)置一臺(tái)核心路由交換機(jī),與INTERNET、IPTV點(diǎn)播服務(wù)器連接。本期網(wǎng)絡(luò)建設(shè)節(jié)點(diǎn)之間的