摘要： 按照单播树、多播树和网状3种重叠网络构建方式分析现有的P2P应用层组播结构，提出构建P2P应用层组播时深度与宽度的平衡、如何利用叶子结点、网络波动的影响等几个普遍问题。给出了一种新的自适应出度的P2P应用层组播算法，试验证明利用结点带宽的异质性可以有效平衡深度、结点度，提高叶子结点的利用率。

关键词: 自适应出度, 异质带宽, 组播树, 应用层组播

Abstract: Analyzing three overlay constructions of the P2P-based ALM from single-tree, multi-tree to mesh, this paper considers some key problems affecting the multicast performances including the tradeoff between depth and out degree, the available ratio of leaf nodes, and the influence on the churn of overlay. A new P2P multicast algorithm is proposed to solve the impact of heterogeneity in the outgoing bandwidth capabilities of nodes through an adaptive out degree method. The experiments show it can make efficient tradeoff between depth and out degree, increasing the available ratio of leaf nodes.

Key words: adaptive out degree, heterogeneous bandwidth, multicast tree, application layer multicast

中图分类号: 

• TP393