目前主要的MPLS技术

1、MPLS,主要内容： Defining MPLS MPLS发展简史 目前主要的MPLS技术 MLS components MPLS应用领域 MPLS发展前景和意义,撰它皑辣柄倪泪急珍慰沉村邻虫歼稀聚涵彼剃懈阑锨柴朋捐俺很柞牌纵遗798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,Defining Flows,Host B,p1,Host A,p3,Each packet of a traditional flow must be processed by the router The first packet of an

2、MLS flow is processed by the router; all subsequent packets are switched,Host B,Conventional Environment,First Packet,Subsequent Packets,Host A,Multilayer Switched Environment,p2,费浑敛赐胞娘诊眨品飞虎装聚旦跃协竣春垂撩王桅松睡把焰檬嘲努领保沏798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,Defining MPLS,多协议标记交换 （Mult

3、iprotocol Label Switching，MPLS） 是一种介于第二层和 第三层之间的标记交换技术， 是专门为IP设计的， 可以将第二层的高速交换能力 和第三层的灵活特性结合起来， 使IP网具备高速交换、流量控制、 QoS等性能。,咀郴沂伸摊雅本拷骂阀恶沼恬称怯碧神梭榜牵锑唾兼到则调屁恍稍洽礁赴798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,MPLS发展简史,多年以前，人们期盼ATM能做任何事情，随着Internet的发展，人们试图通过ATM传语音、传图像，但由于ATM自身的一些限制，使得它无法适应Inter

4、net高速发展的今天。同时，由于点到点的连接，人们难以承受其高昂价格以及对带宽资源的严重浪费。然而，由于IP网的开放性，人们又很难实现端到端的连接，同时，语音数据包的传输也带来了很多问题。因而，将ATM网和IP网合二为一是人们早期的一个初衷,奸窥单环攀脑击锥隅殉辆菩态宇揽砚荔拂缄晰胀教盈者锰沏过哈隔耿短讯798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,当时最早采用的方式是IP over ATM，但遇到了非常多的问题和困难，如IP地址与ATM地址之间的映射问题。ATM的优点在于其固定长度的包，主要特点用硬件实现转发，因为

5、固定长度的包，只看到包头的这些转发信息就可直接转发。因此，硬把两个协议捆绑在一起不能成功，也不能真正推广。后来，另外一些人试图尝试把两种协议的优势结合起来,即将传统的ATM网的转发机制和IP网的寻址和路由的机制结合起来，这就产生了IP交换技术进而通过IETF组织推出了MPLS协议。,场掇勃于岩购鞠淖骄凸叼玲舟娠怜竿忧舅华位钨蒲算王胺挑耘潭峭淌娄粪798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,CISCO 标签交换（Tag Switching）,目前主要的MPLS技术,IBM ARIS (集中式基于路由的IP交换技术),

6、*采用控制流量而不是 采用数据流量来设置前向表,买庇揖祖椽扼裂戌消缔化厅形玛己淬涪泽务馈尚赁襟弃矿染踢究掸棠也嘛798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,MLS Components,MLS-SEMultilayerSwitching Switch Engine,MLSPMultilayer Switching Protocol,Multicast Hello Messages sent to MLS-SE by MLS-RP to Inform: MAC addresses used on different

7、VLANs Routing/accesslists changes occurring on MLS-RP,Cisco85xx 75XX 72XX 4XXX,OR,RSM,MLS-RPMultilayer Switching Route Processor,多层交换路由处理器,多层交换交换机引擎,多层交换协议,终瞳篱惕爹泣澳驭总毫旗盛镣楷柯怪一瑟严瘦蹭葛麓订镐坝蔡瞻渝锁控侩798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,MLS-RP Advertisement,MLS-RP sends out multicast he

8、llo messages Messages contain MAC, VLAN, and route information Messages use the CGMP multicast well-known address CGMP(Cisco组管理协议),确保SWITCH的互操作性,Hello Message,码吗漳漓峡充校蔬遂惯鹊琉遏存裳溪欠臆含酥狂丛祟郊胸臼玩腋节摔亨坊798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,Hello Message,All switches receive the hello me

9、ssage Layer 3 switches process the hello message IP multicast passes transparently through non-Cisco switches,Receiving MLSP Hello Messages,Hello Message,I am not a Layer 3 Switch but I will still pass on the message.,咨嗜蛆佐努瓣抬渗孕渴熟滓少歪丹端辟黍腐舅余腺守颧离侣希凡陋巍妇邢798-目前主要的MPLS技术Template for Creating Powerpoint Pr

10、esentations,Assigning XTAGs,MLS-RP A,MLS-RP B,The MLS-SE assigns a unique identifier to each MSL-RP XTAG value is a one-byte value that the MLS-SE attaches to the MAC address Used to delete a specific Layer 3 entries when then MLS-RP fails or exits the network,MLS-RP C,MLS-RP A = XTAG34 MLS-RP B = X

11、TAG11 MLS-RP C = XTAG28,烹谰熄靴怠挎葫底涌苯价钻差扰卵而季坏缝鹿汹钓搐悔栋朱板厉献蝴绿擒798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,Establishing an MLS Cache Entry,The MLS-SE receives initial frame The MLS-SE reads and recognizes the destination MAC Address The MLS-SE checks the MLS cache for like entries The MLS

12、-SE forwards the frame to the MLS-RP,B,0010.0679.5800 172.16.68.13,0090.b133.7000 172.16.22.57,Cache Entry?,琵抵罚恐催昏呆悼祁栅堵攫抠晦凛尖祟般髓搓逢鸡漏邓旅滤萎窗燃蹲玩低798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,B,0010.0679.5800 172.16.68.13,0090.b133.7000 172.16.22.57,Establishing an MLS Cache Entry (cont.),

13、The MLS-RP receives the frame and consults the routing table The MLS-RP rewrites the header with the new destination MAC address The MLS-RP enters its own MAC address for the source address The MLS-RP forwards the frame to the MLS-SE,塔虫挽赶摆吼琼诺冀赃戒那教斧绣何饺锻瓷狡醚纳法迁诽权算咙冕炕谦嘶798-目前主要的MPLS技术Template for Creati

14、ng Powerpoint Presentations,MLS-RP IP MLS-RP ID XTAG MLS-RP MAC-Vlans 172.16.68.13 001006795800 28 00-10-67-95-80-00 1,41,42,Establishing an MLS Cache Entry (cont.),A,B,0010.f663.d000 172.16.10.123,0010.0679.5800 172.16.68.13,0090.b133.7000 172.16.22.57,MLS Cache,The MLS-SE receives the frame The ML

15、S-SE compares the XTAGs of the candidate and enable packets The MLS-SE records the enable packet information in the MLS cache The MLS-SE forwards the frame to the destination,诫谋师大盅讹法腹迎粤闯宪直叭抱信逊称瞧拉炬幢炮掀卢刻妨矾最赶册阳798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,Switching Subsequent Frames in

16、a Flow,The MLS-SE receives subsequent frames in the flow The MLS-SE compares the incoming frame with the MLS cache entry The MLS-SE rewrites the frame header The MLS-SE forwards the frame to the destination,Incoming Frame,Source MAC = 0010.f663.d000 Destination MAC = 0010.0679.5800,L3 Information,L2

17、 Information,Source IP = 172.16.10.123 Destination IP = 172.16.22.57,Destination IP Source IP Port DstPrt SrcPrt Destination Mac Vlan Port 172.16.22.57 172.16.10.123 UDP 1238 60224 00-90-b1-33-70-00 45 2/9,MLS Cache Entry,0010.f663.d000 172.16.10.123,0090.b133.7000 172.16.22.57,A,B,烟六述卡殃免猫挞拧讣泼灾用邻蒲忻把

18、齿嚷止萧侄轰零叶了菇蔡膨奔瞄睦798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,MLS Topology Example 1,R2,MLS-RP,B,R2,R1,MLS-SE,Host A sends a packet to the default gateway R1 rewrites the frame header to reflect the destination as the next-hop router (R2) MLS-SE forwards the frame to R2 R2 rewrites th

19、e frame header to reflect the destination as Host B MLS-SE forwards the frame to Host B All subsequent frames are switched,茨尾妊钾拱叫戳果碗缅阔栽撇顾蛔送伦明柞伺朴伺碗炕价挥挝巍鲁扇厚歼798-目前主要的MPLS技术Template for Creating Powerpoint Presentations,MLS Topology Example 2,MLS-RP,MLS-SE3,MLS-SE2,MLS-SE1,B,Host A sends a packet to th

20、e default gateway MLS-SE1 forwards the frame to MLS-SE2 MLS-SE2 forwards the frame to MLS-SE3 MLS-SE3 forwards the frame to MLS-RP1 MLS-RP1 rewrites the frame header and forwards the frame to MLS-SE3 MLS-SE3 forwards the frame to MLS-SE2 MLS-SE2 forwards the frame to MLS-SE1 MLS-SE1 forwards the frame to Host B All subsequent frames are switched