Measurement method of one-way differential delay for end-to-end path selection on multihoming

In a multihoming communications environment in which multiple communications interfaces are connected to a single terminal to use multiple paths, if different paths are used for the going-out path and return path, more efficient information communications may be possible. To enable this to occur, one-way delay must be taken into account to select the appropriate interface. However, it is generally difficult to directly obtain an accurate one-way delay because the communications path load varies according to such factors as the time period and amount of communications, and the going-out path delay and return path delay cannot be easily separated. In this paper, the authors simply obtain the one-way approximate differential delays from multiple patterns of round-trip delay combinations and propose a method of selecting the path based on these differentials. This method has such features as control packets for measurement and synchronization with the communication destination which are unnecessary and it is extendable since it does not depend on the network layer. The authors also implemented the proposed method on a computer by using ICMP and evaluated it experimentally in various types of multihoming communications environments. The results showed that one-way path selection is possible and that the proposed method is effective. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(6): 29–42, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20321