具有星际链路的双层通信星座网络可为全球提供宽带实时多媒体通信服务，路由算法设计是其中关键技术之一。本文详细介绍了由低轨卫星与中轨卫星构成的空间信息通信网双层星座系统体系结构，提出了一种新的具有QoS保证的双层卫星网络路由算法。仿真结果表明提出的路由算法可以满足系统的QoS业务要求的延迟、丢包率与抖动等指标。

近年来。随着网络技术的迅猛发展和互联网（Internet）应用的日益广泛，网络性能测量技术成为网络研究领域的热点。网络测量的研究成果对网络的发展具有重要的指导作用。本文综述了网络测量的重要意义、测量指标体系与常用性能指标；回顾国际上在网络性能测量领域所做的工作及取得的进展；对性能测量方法进行分类，总结有效网络测量方法的评价准则；阐述了高速网络环境下进行性能测量的关键技术与难点。最后时进一步的研究工作进行初步探讨。

传统的基于应用层的网卡监测方式已难以对高速网卡活动信息进行实时、准确监测。为此，分析基于NDIS（network drivet interface specification）中间层驱动和Window8网络数据包过滤技术的特点，采用核心态NDIS中间层驱动程序实现了与底层网络接口设备具体细节无关的高速网络设备监测技术，设计并实现了windows平台下基于NDIS的网卡监测器。它分为应用层和驱动层两个模块，能够在保证高性能的情况下在数据链路层同时对多个网卡进行精确监测，其主要特点是对所有数据包的分析处理都在核心态进行。

The end-to-end delay of Internet is a fundamental indicator for network performance evaluation and has been becoming a hot issue in network measurements in recent years. There are two kinds of metrics related to the end-to-end latency, i.e., Round Trip Delay and One-way Delay metric. In the paper, we survey the recent progresses on these two types of metrics measurement. Special concerns are on the clock synchronization issue in one-way delay measurement. The problems in deploying end-to-end delay measurement and the timestamping issue are also summarized. The potential new research directions in delay measurement and analysis are discussed.

The long-tailed distribution characterizes many properties of Internet traffic. The property is often modeled by Lognormal distribution, Weibull or Pareto distribution theoretically. However, it hinders us in traffic analysis and evaluation studies directly from these models due to their complex representations and theoretical properties. This paper proposes a Hyper-Erlang Model (Mixed Erlang distribution) for such long-tailed network traffic approximation. It fits network traffic with long-tailed characteristic into a mixed Erlang distribution directly to facilitate our further analysis. Compared with the well-known hyperexponential based method, the mixed Erlang model is more accurate in fitting the tail behavior and also computationally efficient.