Efficient Marking Techniques for Differentiated Services in the Internet

当前一代互联网的尽力而为服务模型不足以适应不断发展和扩展的应用，如连续媒体，实时应用和电子商务环境。 这些应用程序需要一定的服务质量（QoS）保证，可以通过在互联网上的服务歧视。 区分服务（DiffServ）已经被提出作为用于在因特网中提供服务区分的可行解决方案。 DiffServ以每跳为基础对聚合流量进行操作，从而避免了与集成服务模型相关的可伸缩性问题。 区分服务体系结构的一个主要组成部分是标记器，该标记器基于相邻互联网域之间的服务级别协议（域间标记器）或端节点与其最先域之间的服务级别协议（叶标记器）来标记分组。 因特网核心路由器基于分组的标记来区分地路由分组。因此，标记技术对区分服务的性能有着重要的影响。 该建议的重点是设计和实施有效的标记技术，在互联网上的差异化服务。 本研究针对域间标记和叶标记的标记问题进行研究。我们正在努力的标记方案域间标记地址随机和早期降级和升级的数据包，以提高带宽利用率，同时保持不同的流之间的公平性。 该方法采用三色标记方案，并使用改进的漏桶技术进行流量控制。 详细的性能研究，各种参数的影响，使用多个优先级，和流量控制技术将使用ns模拟器进行调查。 在叶标记的上下文中，我们建议将标记方案与端节点的TCP层相结合。 因此，除了域间层的聚合级流量控制之外，我们还将实现一定程度的流级服务差异化。 我们的方法是基于分裂的TCP拥塞窗口逻辑上所需的服务水平的基础上。 在拥塞期间，拥塞窗口的分裂得到相应于它们的相对服务水平协议的影响。 这样的方法还将使得流控制在具有不同服务水平协议的多个流之间是公平的。 在先前的几项研究中，比例公平的维护一直是一项艰巨的任务。 我们建议通过一个实验性的实施，以评估所提出的叶标记的影响。 拟议研究的结果将对互联网基础设施及其用户产生更广泛的影响。 具体而言，所提出的技术将提高带宽利用率在互联网上，同时提供差异化的服务。 在地方一级，这项研究将对密歇根州立大学的学生产生积极的教育影响。

The best-effort service model of the current generation Internet is not adequate for evolving and expanding applications such as continuous media, real-time applications, and e-commerce environments. These applications require certain quality of service (QoS) assurance that could be provided through service discrimination in the Internet. Differentiated Services (DiffServ) have been proposed as a viable solution for providing service differentiation in the Internet. DiffServ operates on the aggregate traffic on a per-hop basis and thus avoids the scalability problems associated with the integrated service model. A major component of the DiffServ architecture is the markers that mark packets based on the service level agreements between adjacent Internet domains (interdomain makers) or between the end node and its ver first domain (leaf markers). The Internet core routers route packets discriminatley based on their marking. Thus the marking technique affects the performance of DiffServ significantly. This proposal focusses on the design and implementation of efficient marking techniques for differentiated services in the Internet. The proposed research targets the marking issues at both the interdomain markers and the leaf markers. Our ongoing effort on the marking scheme for interdomain marker addresses random and early demotion and promotion of packets to improve the bandwidth utilization while maintaining fairness between different flows. This approach employs a three-color marking scheme and uses a modified leaky bucket technique for flow control. A detailed performance study, impact of various parameters, usage of multiple precedence levels, and flow control techniques will be investigated using the ns simulator. In the context of leaf markers, we propose to integrate the marking scheme with the TCP layer at the end nodes. Thus in addition to the aggregte level flow control at the interdomain layer, we will also achieve some degree of flow-level service differentiation. Our approach is based on splitting the TCP congestion window logically on the basis of the desired levels of services. During congestion, the splits of the congestion window gets affected corresponding to their relative service level agreements. Such an approach would also make the flow control fair across multiple flows with different service level agreements. Maintenance of proportional fairness has been observed as a difficult task in several prior research. We propose to evaluate the impact of the proposed leaf marker through an experimental implementation. The outcome of the proposed research will have a broader impact on the Internet infrastructure and on its users. Specifically, the proposed techniques will improve the bandwidth utilization in the Internet while providing differentiated services. At the local level, the research will have a positive educational impact on the students of Michigan State University.