Accommodating Network Evolution and Heterogeneity by Improving Network Transparency

互联网的核心设计原则之一是这样一种思想，即网络只需实现一组最小的功能（IP协议），就足以允许网络互操作和任何两个节点进行通信。 然而，由于这个原因，许多最近的网络技术（例如，无线、长延迟和频繁中断的链路）难以集成到互联网中。这个项目探讨了两个核心技术，使更好地支持不寻常的链接：显式路径查询和端到端的适应。互联网对明确路径查询的支持将允许端点了解用于其通信的链接的关键属性。日本早稻田大学和AIST的i-Path系统为这种路径查询机制提供了基础。新的端到端自适应机制将允许端点根据通信路径的能力或特性调整其行为，特别是，该项目正在修改两个端点系统以响应路径查询结果：1）TCP拥塞控制和重传以及2）多媒体流应用。这项工作预计将显示这样的系统应该如何适应路径属性，如延迟，带宽，丢失率，路由器缓冲和网络内压缩支持。这项工作的更广泛的影响来自于显示显式路径查询对于简化向Internet添加新技术至关重要。通过降低支持链接新技术的门槛，这项研究使许多系统能够产生重大的社会影响，例如老年人家庭护理传感器，以及与欠发达地区的延迟容忍链接。

One of the core design principles of the Internet is the idea that it is sufficient for networks to implement a minimal set of functionality (the IP protocol) to allow networks to interoperate and any two nodes to communicate. However, many recent network technologies (e.g. wireless, long-latency and frequently-disrupted links) have been difficult to integrate into the Internet for this reason. This project explores two core techniques that enable better support for unusual links: explicit path queries and end-to-end adaptation. Internet support for explicit path queries would allow end-points to learn key properties of the links used for their communication. The i-Path system from Waseda University and AIST in Japan provides the foundation for this path query mechanism. New end-to-end adaptation mechanisms would allow end-points to adapt their behavior to the capabilities or quirks of the communication path. In particular, the project is modifying two end-point systems to react to path query results: 1) TCP congestion control and retransmission and 2) multimedia streaming applications. This effort is expected to show how such systems should adapt to the path properties, such as latency, bandwidth, loss rate, router buffering and in-network compression support. The broader impact of this work comes from showing that explicit path querying is critical for simplifying the addition of new technologies to the Internet. By lowering the bar for supporting link new technologies, this research enables a number of systems that will have significant social impact, such as sensors for elderly homecare, and delay-tolerant links to underdeveloped regions.