Title: Why Path-Based Adaptation? Performance Implications of Different
       Adaptation Mechanisms for Network Content Delivery


Authors: Xiaodong Fu and Vijay Karamcheti


Because of heterogeneous and dynamic changing network environments, 
content delivery across the network requires system support for 
coping with different network conditions in order to provide 
satisfactory user experiences. Despite the existence of many 
adaptation frameworks, the question that which adaptation approach
performs the best under what network configurations still remains 
unanswered. The performance implication of different adaptation 
approaches (end-point, proxy-based and path-based approaches) 
has not been studied yet. This paper aims to address this 
shortcoming by conducting a series simulation-based experiments
to compare performance among these adaptation approaches under 
different network configurations. In order to make a fair 
comparison, in this paper approach-neutral strategies are proposed
for constructing communication paths and managing network resources.
The experiment results show that there are well-defined network 
environments under which each of these approaches delivers its best
performance; and among them, the path-based approach, which uses 
the whole communication path to do adaptation, provides the best and
the most robust performance under different network configurations,
and for different types of servers and clients.