IPv6流标签提供的服务质量支持

Aspects of IPv6 Flow Label in Supporting QoS

作为下一代互联网协议,IPv6除了在地址空间上明显优于IPv4之外,还在数据报头中保留了20位流标签字段为实时流提供有别于尽力而为流的服务。流标签的研究尚处于试验阶段,目前还没有制定出正式的规范。本文在介绍了流和流标签的定义及属性之后,从流标签支持包分类、加速包转发、支持资源预留以及支持QoS的格式定义等多个方面探讨了流标签支持服务质量的能力,分析各种方式的利弊.给出可能的发展方向。

As the next generation Internet Protocol, IPv6 has obvious advantages in extending address space. Another important fact is that IPv6 also defines 20-bit Flow Label to support QoS of real-time flows, and to provide service better than pure best effort delivery. Currently there is no standardized specification of flow label, and a lot of research works are still in experimenting stage. This paper first describes variant types of flows and their characteristics, and then introduces definition of Flow Label in IPv6 briefly. The paper mainly focuses on discussion about variant methods to use Flow Label to support quality of service, such as packet classification, packet forwarding, resource reservation and different QoS description formats in Flow Label. The paper finally analyzes the advantages and disadvantages of each method, and gives some potential research direction in future.