CCNP ONT QoS-in-VPN.pptVIP

Implement the DiffServ QoS Model Implementing QoS Preclassify 执行QoS预分类(VPN中允许数据包在隧道化和加密之前执行分类而进行QoS管理) QoS Preclassify VPNs are growing in popularity. VPN发展大受欢迎 The need to classify traffic within a traffic tunnel is also gaining importance. 隧道化流量需要进行分类 QoS preclassify is a Cisco IOS feature that allows packets to be classified before tunneling and encryption occur. QoS预分类特性允许数据包在隧道化和加密之前执行分类 Preclassification allows traffic flows to be adjusted in congested environments. 在拥塞的环境中预分类允许对流量进行调整 QoS Preclassify Applications When packets are encapsulated by tunnel or encryption headers, QoS features are unable to examine the original packet headers and correctly classify packets. 当数据包通过隧道和加密包头之后，QoS特性不能检查到最初的报头和对数据包进行分类 Packets traveling across the same tunnel have the same tunnel headers, so the packets are treated identically if the physical interface is congested. 通过相同隧道的数据包有相同的隧道报头，如果物理接口拥塞，这些隧道数据包将被等同对待 QoS Preclassify Applications When packets are encapsulated by tunnel or encryption headers, QoS features are unable to examine the original packet headers and correctly classify packets. Packets traveling across the same tunnel have the same tunnel headers, so the packets are treated identically if the physical interface is congested. GRE Tunneling ToS classification of encapsulated packets is based on the tunnel header. TOS分类是基于隧道报头的 By default, the ToS field of the original packet header is copied to the ToS field of the GRE tunnel header. 默认情况下，原始报头的TOS值将复制到GRE报头中的TOS字段中 GRE tunnels commonly are used to provide dynamic routing resilience over IPsec, adding a second layer of encapsulation. GRE隧道通常使用IPsec来保证数据的安全 IPsec ESP IPsec ESP supports both authentication and encryption. ESP支持认证和加密 IPsec ESP consists of an unencrypted header followed by encrypted data and an encrypted trailer. With tunnel mode, the ToS byte value is copied automatically from the original IP header to the tunnel header. 隧道模式，TOS字节直接自动复制到隧道报头中 GRE over IPsec Characteristics GRE encapsulates