CCUCOMM 網路前瞻實驗室 Yi-Chi Cheng 鄭伊騏 期中報告 CCUCOMM 網路前瞻實驗室 Yi-Chi Cheng 鄭伊騏 ANT LAB@CCU COMM

Outline Introduction HTB Future Work ANT LAB@CCU COMM

Hierarchical Token Bucket (1/2) HTB is one of the packet scheduler. It is currently included in stock Linux kernels from 2.4.20. Control the use of the outbound bandwidth on a given link. Using one physical link to simulate several slower links. ANT LAB@CCU COMM

Hierarchical Token Bucket (2/2) Send different kinds of traffic on different simulated links. Ensures that the amount of service provided to each class is at least the minimum of the amount it requests and the amount assigned to it. Allow “lower” priority queue to borrow the bandwidth form the higher priority queue when it’s idle. ANT LAB@CCU COMM

Traffic control for Linux (1/3) Consist of Queuing disciplines (Qdisc) , classes and filters. filter queuing discipline class packet filter class queuing discipline filter queuing discipline function ANT LAB@CCU COMM

Traffic control for Linux (2/3) Filter 依據封包的來源不同(IP或port)，來決定其Class Class 依據Application及Data type不同，分送到不同的Queuing Discipline Queuing Discipline 不同的Qdisc會有不同的排程方式，如：FIFO ANT LAB@CCU COMM

Traffic control for Linux (3/3) Classful qdisc : CBQ, HTB Classless qdisc : FIFO, TBF, RED Application Aware: 固定port Dynamic port:依據signaling內容來處理 ANT LAB@CCU COMM

Introduction AR: Assure rate CR: ceil rate Mode: Red：R>CR [HTB_CANT_SEND] Yellow：R ≦ CR and R > AR [HTB_MAY_BORROW] Green：otherwise [HTB_CAN_SEND] ANT LAB@CCU COMM

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Future Work Measure the performance of the VoIP transmission with HTB and without HTB. Find out why HTB can’t run so precisely? ANT LAB@CCU COMM