This paper compares the three technologies of IP Over ATM(LAN emulation, IP switch, Tag switch) and thencompares the technology of IP Over ATM with the technology or IP Over SDH/SONET in general.

• 首先对当今IPOverATM技术采用的设计方案（局域网仿真，IP交换，标签交换）进行了详细的分析与比较，然后在总体上将IPOverATM与IPOverSDH/SONET技术进行了比较。