混合的ATM技术

Hybrid ATM

ＡＴＭ协议体系结构分为物理层、ＡＴＭ层、ＡＡＬ层和高层，如果在终端用户处完全实现这些功能，不仅造价大，还要放弃用户在网卡、网络软件上的投资。而在终端用户的协议栈中采用混合的方案，则既能保留现有网络技术的一些协议层次，又加入ＡＴＭ的协议层次，可以在将用户接入ＡＴＭ网的同时，保护用户已有的网络投资。ＩＰｏｖｅｒＡＴＭ、ＡＴＭ局域网仿真、ＤＸＩ、ＣＩＦ便是这种混合的ＡＴＭ技术。

To implement the layered ATM protocol infrastructure completely in the end system,i.e.,physical layer.ATM layer,ATM daptation layer and high layer,means not only a higher cost but also the abandonment of NICs and network software.The hybrid ATM,e.g.,IP over ATM,ATM LAN emulation,DXI and CIF,adopts partial traditional protocol layers and partial ATM layers and mixes them deliberately.Therefore,the hybrid ATM can connect the end systems to the ATM networks,in the meanwhile,protect the investment of the users in the networks.This paper overviews,analyzes and compares these hybrid ATM schemes.