【正文】 n 高可靠性S3900不僅支持STP/RSTP/MSTP生成樹協(xié)議，還提供Smartlink技術(shù)，能實現(xiàn)主備鏈路毫秒級倒換，解決了電信級業(yè)務(wù)接入可靠性問題。增強型支持復雜的路由協(xié)議和豐富的業(yè)務(wù)特性，支持全部的IRF功能（分布設(shè)備管理、分布冗余路由和分布鏈路聚合）。 S3900系列智能彈性以太網(wǎng)交換機（以下簡稱S3900）是華為公司為設(shè)計和構(gòu)建高彈性、高智能網(wǎng)絡(luò)需求而推出的新一代以太網(wǎng)交換機產(chǎn)品。通過各種開放的標準MIB和擴展MIB的支持可以提供完善的基于SNMP的第三方管理能力。支持CAR（Committed Access Rate）功能，可以實現(xiàn)基于端口和基于流的速率限制，限制的粒度可以精確至64Kbps，為網(wǎng)絡(luò)帶寬的精細化管理提供了手段。支持在設(shè)備上配置多條等價路由的方式實現(xiàn)上行路由的冗余備份，當主上行路由發(fā)生故障時自動切換到下一條備份路由，實現(xiàn)上行路由的多級備份。n 高可靠性S5600系列交換機采用IRF技術(shù)組網(wǎng)后，能夠在整個堆疊組內(nèi)實現(xiàn)控制平面和數(shù)據(jù)平面所有信息的冗余備份，極大地增強了設(shè)備和網(wǎng)絡(luò)的可靠性，消除了單點故障，避免了業(yè)務(wù)中斷?？梢詣討B(tài)的為通過認證的用戶提供預先配置的一套QoS功能。在用戶接入網(wǎng)絡(luò)時完成必要的身份認證，還可以通過靈活的MAC、IP、VLAN、PORT任意組合綁定，有效的防止非法用戶訪問網(wǎng)絡(luò)。硬件支持二/三層線速交換，能夠識別、處理四到七層的應(yīng)用業(yè)務(wù)流，所有端口都具有單獨的數(shù)據(jù)包過濾、區(qū)分不同應(yīng)用流，并根據(jù)不同的流進行不同的管理和控制。通過支持POE和Voice VLAN技術(shù)，S5600系列交換機能夠提供完美的數(shù)據(jù)和語音融合解決方案。3) DLA（分布鏈路聚合）：支持跨設(shè)備的鏈路聚合，可以在設(shè)備之間進行鏈路的負載分擔和互為備份。用戶可以通過CONSOLE、SNMP、TELNET、WEB等多種方式來管理整個Fabric。前面板提供24個千兆SFP接口和4個o的10/100/1000BaseT自協(xié)商以太網(wǎng)端口（RJ45連接器）產(chǎn)品特點n IRF智能彈性架構(gòu)技術(shù)S5600系列全千兆智能彈性交換機支持華為創(chuàng)新的IRF（Intelligent Resilient Framework）技術(shù)，能夠?qū)崿F(xiàn)用戶網(wǎng)絡(luò)的高度彈性智能擴展。后面板提供兩個固定的堆疊接口和一個擴展模塊插槽，擴展模塊可選配8端口千兆SFP模塊、1端口萬兆模塊或2端口萬兆模塊。系統(tǒng)采用華為公司創(chuàng)新的IRF（Intelligent Resilient Framework，智能彈性架構(gòu))技術(shù)，支持高達96G的堆疊帶寬和高密度千兆端口，支持萬兆上行。n 完善的安全機制S8500支持OSPF 、RIP v2及BGP v4報文的明文及MD5密文認證；，支持安全的SNMP v3網(wǎng)管協(xié)議、支持配置安全，對登錄用戶進行認證，不同級別的用戶有不同的配置權(quán)限，并提供兩種用戶認證方式：本地認證和RADIUS認證。n 支持完善QinQ特性S8500支持靈活QinQ功能，可以根據(jù)內(nèi)層VLAN tag靈活標記外層VLAN tag，滿足城域接入網(wǎng)一般建設(shè)需求。 S8500系列核心路由交換機提供大容量、高密度、模塊化體系架構(gòu)，提供二、三層線速轉(zhuǎn)發(fā)能力，具有強大的IP路由功能，同時支持分布式的IP/MPLS線速轉(zhuǎn)發(fā)、完善的QoS保障、有效的安全管理機制和電信級高可靠設(shè)計，滿足用戶對多業(yè)務(wù)、高可靠、大容量的需求，可廣泛應(yīng)用于IP城域網(wǎng)、大型園區(qū)網(wǎng)的交換核心和匯聚中心。 4 設(shè)備推薦及特性介紹 核心路由交換機S8508由于該網(wǎng)絡(luò)層次簡單,覆蓋地域較小,主要承載VOD點播等封閉流量. 所以需要網(wǎng)絡(luò)設(shè)備具備大容量快速轉(zhuǎn)發(fā)能力,S8500具有720G交換機能力,更適合該類需求。業(yè)務(wù)網(wǎng)絡(luò)時延上限延時抖動上限丟包率上限包誤差率上限視頻直播1s1s1/10001/10000視頻點播10s1s1/10001/10000視頻會議400ms50ms1/10001/10000游戲200msN/AN/AN/A建議整體網(wǎng)絡(luò)拓撲圖如下：本工程建議在中心機房設(shè)置核心層設(shè)備S8508 1臺，配置雙個引擎，冗余交流電源模塊。216。216。216?！璚hen setting dominates, or when a piece of fiction is written largely to present the manners and customs of a locality, the writing is often called local color writing or regionalism and the writer, a regional writer.Apparently, the author makes a contrast between the ugly jailhouse with a tangled grassplot overgrown with burdock and pigweed and something as beautiful as a wild rose. As the story unfolds, he will further suggest that secret sin and a pretty child may go together like a pigweed and wild roses. In this artfully crafted novel, setting is intimately blended with characters, symbolism, and theme. she loved the place and was loved in the place. The vale, far from the madding crowd of the civilized city, was as serene and pure as the inhabitants. Tess, imbued deeply with the natural hue of the vale and bound closely to this world of simplicity and seclusion, experienced her own delight and happiness though her family was poor. It was, to some extent, her departure from her native place that led to her tragedy. In The Return of the Native, the atmosphere of Egdon Heath prevails over the whole book。 (3) the time or period in which the action takes place, for example, the late eighteenth century in history or winter of the year。Usually, a setting consists of time and place. It can also mean circumstances such as Midas’s mentality. A setting may be detailed or sketchy. It depends on the novelist’s purpose of writing and his idea of works of art. A setting may or may not be symbolic. Generally, a setting is more concerned with the physical aspects. Setting is closely related with exposition in that they both help to make possible the events in the novel. In fact, an exposition must have a setting. But setting goes along with every event in the novel whereas exposition is only the initiating action.“Once upon a time there lived a king named Midas in Phrygia. He loved gold more than anything else but his little daughter.” Does the story contain any especially curious objects, mysterious flat characters, significant animals, repeated names, special allusions, or whatever, that hint towards meanings larger than such things ordinarily have? In literary stories, such symbols or metaphors may point to central themes. P, and Faulkner’s Barn Burning concern the theme of “initiation into maturity.” Such general descriptions of theme can be useful, especially if we want to sort a large number of stories and novels into rough categories, but the fact that they are similar in theme does not mean that they mean the same thing. The attitude towards the theme may be very different: the tone of treatment may be, for example, either ic or tragic, straightforward or ironic. The writer’s vision of life is the special underlying fact of a story, and a theme, abstractly stated, is not the same thing as a vision of life. And we suggest anyway that, in the beginning, you look for whatever truth or insight you think the writer of a story intends to reveal. Try to state a theme in a sentence. By doing so, we will find ourselves looking closely at the story. Kennedy and Gioia make a helpful suggestion to consider the following points when we think about the theme of a story:借助上述流分類方法，實際實現(xiàn)了根據(jù)不同用戶、不同業(yè)務(wù)、不同優(yōu)先級等對報文進行外層VLAN tag封裝，對多種業(yè)務(wù)實施不同承載的方案57opinion about, and statement of, the theme.這樣，如果接收到的是已經(jīng)帶有VLAN Tag的報文，該報文就成為雙Tag的報文；如果接收到的是untagged的報文，該報文就成為帶有端口缺省VLAN Tag的報文。MPLS VPNs擴展性好，每個服務(wù)提供商可以設(shè)定數(shù)十萬VPN， 每個VPN 可有數(shù)千個現(xiàn)場。MPLSVPN能夠在提供原有VPN網(wǎng)絡(luò)所有功能的同時，提供強有力的QoS能力，具有可靠性高、安全性高、擴展能力強、控制策略靈活以及管理能力強大等特點。標簽交換的工作流程如下：由LDP（標簽分發(fā)協(xié)議）和傳統(tǒng)路由協(xié)議（OSPF等）在LSR中建立路由表和標簽映射表。P 路由器并也不知道有VPN的存在，僅僅負責骨干網(wǎng)內(nèi)部的數(shù)據(jù)傳輸，但其必須能夠支持MPLS協(xié)議，并使能該協(xié)議；PE位于服務(wù)提供商網(wǎng)絡(luò)的邊緣，所有的VPN的構(gòu)建、連接和管理工作都是在PE上進行的。采用MPLS VPN技術(shù)可以把物理上單一的IP網(wǎng)絡(luò)分解成邏輯上隔離的網(wǎng)絡(luò)，并且每個VPN單獨構(gòu)成一個獨立的地址空間，即VPN之間可以重用地址，在分配地址時不必考慮是否會與其他的VPN發(fā)生沖突，只需要考慮在本VPN之內(nèi)不沖突即可，這樣可以解決IP網(wǎng)絡(luò)地址不足的問題，也方便網(wǎng)絡(luò)的擴展和變更。接入部分兩邊目前都已跨入吉比特級以上的速率，如用戶端廣泛使用的PC其內(nèi)部傳送速率已達到千兆比特速率；而作為接入部分的另一頭，～10 Gbps，它們都比接入部分高出至少3個數(shù)量級。實現(xiàn)多種業(yè)務(wù)的安全隔離，避免相互干擾，充分保證各業(yè)務(wù)的安全性。要以市場為導向，如果建設(shè)太超前，原始投資就不能馬上全部得到收益，因此在規(guī)劃中需充分把握技術(shù)先進性與經(jīng)濟適用性的分寸，不能盲目追求功能的先進與完備高可靠性 － 合理選擇設(shè)備、規(guī)劃網(wǎng)絡(luò)結(jié)構(gòu)和路由部署，網(wǎng)絡(luò)具備一定的冗余度和較強的故障自愈能力，保證網(wǎng)絡(luò)穩(wěn)定可靠運行。 網(wǎng)絡(luò)設(shè)計原則實事求是的原則。2) 家庭用戶寬帶上網(wǎng)業(yè)務(wù)在數(shù)字電視網(wǎng)絡(luò)基礎(chǔ)上發(fā)展寬帶數(shù)據(jù)用戶，包括企業(yè)專線、家庭寬帶等以及相應(yīng)