流控技术在分布式路由器FPGA接口卡上的设计与实现

发布时间：2019-06-15 06:04

【摘要】：随着网络技术的发展,网络用户与网络中流量飞速增加,需要连接网络的分布式路由器具有更快的转发速率,而IP报文在路由器FPGA (Field-Programmable Gate Array,现场可编程门阵列)接口卡上的转发主要是通过接口卡内部的FPGA完成,相比于通过CPU (Central Processing Unit,中央处理器)转发报文的方式,具有更快的转发速率。面对增加的业务流量,网络有限的资源无法满足每个用户的业务需求,而流量控制技术,简称流控技术,便是通过控制报文在分布式路由器上的转发速率从而保证网络资源的合理利用。为了达到对业务流量进一步细化的目的,分层流控技术应运而生,分层流控技术可以对多用户、多业务进行分层调度从而完成统一管理。所以,在分布式路由器FPGA接口卡上设计实现流控技术与分层的流控技术是十分必要的。而CAR (Committed Access Rate,承诺访问速率)技术则作为流量控制的主要的技术手段被广泛应用,CAR技术又分为非分层CAR技术与分层CAR技术。本论文在分布式路由器的FPGA的接口卡上设计实现了非分层CAR技术与分层CAR技术。首先,介绍了论文的研究背景、国内外研究现状及本论文的研究内容。随后,对流控相关技术进行相关介绍,包括QoS (Quality of Service,服务质量)技术、CAR技术原理与令牌桶算法。然后,介绍了FPGA接口卡内部结构及报文转发在接口卡内的处理流程。接下来,通过对IQoS (Input QoS,上行QoS)模块、CAR模块的详细设计与实现,完成FPGA接口卡上的非分层CAR技术与分层CAR技术的功能的实现。最后,对具有非分层CAR技术与分层CAR技术的FPGA接口卡进行功能测试进而验证其功能的实现。而通过比较非分层CAR技术场景下与分层CAR技术场景下的报文平均传输时延,可以得到分层CAR技术场景下报文平均传输时延较高的结论,说明尽管分层CAR技术可以通过对多用户、多业务的分层调度从而完成统一管理,但具有更高的传输时延的缺点,所以非分层CAR技术与分层CAR技术各有利弊,需要用户根据不同需求选择合适的CAR技术进行流量控制。
[Abstract]:With the development of network technology, the traffic between network users and the network increases rapidly, and the distributed routers that need to connect to the network have faster forwarding rate. The forwarding of IP messages on the router FPGA (Field-Programmable Gate Array, Field programmable Gate Array) interface card is mainly done through the FPGA inside the interface card, which has a faster forwarding rate than the way of forwarding messages through CPU (Central Processing Unit, central processor (CPU). In the face of increased traffic, the limited resources of the network can not meet the business needs of each user, and flow control technology, referred to as flow control technology, is to ensure the rational use of network resources by controlling the forwarding rate of messages on distributed routers. In order to further refine the traffic flow, hierarchical flow control technology emerges as the times require. Hierarchical flow control technology can schedule multi-user and multi-service hierarchically to complete unified management. Therefore, it is very necessary to design and implement flow control technology and hierarchical flow control technology on distributed router FPGA interface card. CAR (Committed Access Rate, promised access rate) technology is widely used as the main technical means of flow control. CAR technology is divided into non-hierarchical CAR technology and hierarchical CAR technology. In this paper, the non-hierarchical CAR technology and hierarchical CAR technology are designed and implemented on the interface card of FPGA of distributed router. First of all, it introduces the research background, domestic and foreign research status and the research content of this paper. Then, the related technologies of flow control are introduced, including QoS (Quality of Service, quality of service (QoS) technology, CAR technology principle and token bucket algorithm. Then, the internal structure of FPGA interface card and the processing flow of message forwarding in interface card are introduced. Next, through the detailed design and implementation of IQoS (Input QoS, uplink QoS) module and CAR module, the functions of non-hierarchical CAR technology and hierarchical CAR technology on FPGA interface card are completed. Finally, the function of FPGA interface card with non-hierarchical CAR technology and hierarchical CAR technology is tested to verify the realization of its function. By comparing the average message transmission delay between the non-hierarchical CAR technology scenario and the hierarchical CAR technology scenario, we can get the conclusion that the average message transmission delay is higher in the hierarchical CAR technology scenario, which shows that although the hierarchical CAR technology can complete the unified management through the hierarchical scheduling of multi-user and multi-service, it has the disadvantage of higher transmission delay, so the non-hierarchical CAR technology and the hierarchical CAR technology have their own advantages and disadvantages. Users need to choose the appropriate CAR technology according to different needs for flow control.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP393.05

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