Design And Implementation Of Bandwidthcontrol In Linux Based On Quality Of Service

Rapid development of network and multimedia applications lead to Bandwidthdemand grow with each passing day， and it often causes network congestion reducingoverall network efficiency， however， the current network architecture provides onlybest-effort service model can not effectively ensure the quality of transmission， based onthe Bandwidth under the situation of Limited resources， if can use Bandwidthmanagement Bandwidth resources management the most effective allocation， will ensurethat the user basic guarantee Bandwidth， which can improve the transmission quality ofservice (Quality of Service; Qos)， but also can inhibit the abnormal discharge amount anddistribution of Bandwidth， and when the Bandwidth for the distribution of the remainingtime can provide to other multimedia applications， in order to make full use of Bandwidthresources Limited.This paper mainly introduces no TC module transmits the data packet of the generalprocess， sending each packet will call the dev_queue_xmit， and then determine the needto support AF_PACKET protocol to transfer data packets， the last direct calls to the NICdriver send function registered sends packets out. Join the process of sending TC to senddata packets for each packet will call the dev_queue_xmit， and then determine the need tosupport AF_PACKET protocol to transfer data packets， acquisition strategy object usedby current equipment， and then call the enqueue method of the object data bag is pressedinto the queue and calls the object. The dequeue method is removed from the queue ofpackets， sending function to send the final call network card driver.This paper uses the Traffic Control Linux tool to plan and design the Bandwidthsharing architecture，we distinguish data packet of GAME and VOIP，FTP，P2P packetsto their respective characteristics， and then use the HTB (Hierarchical Token Bucket)queue algorithm and Bandwidth management the basic function of the FWFilter and the action and transfer the connection tracking module in IPTABLES the management of thenetwork packet flow.