introducing traffic policing and shaping.ppt

Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Implement the DiffServ QoS ModelIntroducing Traffic Policing and ShapingCisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing and Shaping OverviewCisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing and Shaping Overview• These mechanisms must classify packets before policing or shaping the traffic rate. 数据包必须之前被分类后才能够使用流量监管和流量整形技术． • Traffic policing typically drops or marks excess traffic to stay within a traffic rate limit. 流量监管会丢弃或重标记超额流量． • Traffic shaping queues excess packets to stay within the desired traffic rate. 流量整形使用缓存队列缓存超额的流量．Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Why Use Policing?• To limit access to resources when high-speed access is used but not desired (subrate access) 当不期望的对某个资源高速访问时去限制访问速率（子速率接入）• To limit the traffic rate of certain applications or traffic classes 对确定的应用或流量类别进行速率限制• To mark down (recolor) exceeding traffic at Layer 2 or Layer 3 在第二层或第三层重标记流量．Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Why Use Shaping?• To prevent and manage congestion in ATM, Frame Relay, and Metro Ethernet networks, where asymmetric bandwidths are used along the traffic path 用于阻止和管理流量路径中有不对称带宽的ATM,Frame Relay和 Metro Ethernet网络拥塞. • To regulate the sending traffic rate to match the subscribed (committed) rate in ATM, Frame Relay, or Metro Ethernet networks 用于在ATM, Frame Relay或者Metro Ethernet网络中遵守订购的 流量速率. • To implement shaping at the network edge 在网络边缘实现整形.Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Why Use Traffic Conditioners?Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing Example• Do not rate-limit traffic from mission-critical server. 对关键服务器产生流量不执行速率限制. • Rate-limit file-sharing application traffic to 56 kbps. 将文件共享应用速率限制到56 kbps.Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing Example• Do not rate-limit traffic from mission-critical server. 对关键服务器产生流量不执行速率限制. • Rate-limit file-sharing application traffic to 56 kbps. 将文件共享应用速率限制到56 kbps.Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing and Shaping ExampleCisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing and Shaping Example• Central to remote site speed mismatch 中心站点与远程站点速度不匹配Cisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing and Shaping Example• Central to remote site speed mismatch 中心站点与远程站点速度不匹配 • Remote to central site oversubscription 远程站点到中心站点oversubscriptionCisco Network Academy. All rights reserved CCNP+ ONT v1.0Traffic Policing and Shaping Example• Central to remote site speed mismatch 中心站点与远程站点速度不匹配 • Remote to central site oversubscription 远程站点到中心站点oversubscription • Both situations result in buffering and in delayed or dropped packets.Cisco Network Academy. All rights reserved 。