Hi friends, I've found here is plenty of traffic in the list, so I hope my question can be answered. Thanks in advance. I'm curretly on a survey of current broadband data network backbone. And I 've heard that many ISP, or US national testbed has adopted ATM as the infastructure to support upper layer IP service, such as UUnet (siad have around 300 ATM switch connected, really?), vBNS, Internet2, Sprint .... But I just can't find detailed discription about their network architecture and method/model to integrated IP with ATM, only some network topology map and service info can be found in their site (except in vBNS, comprehensive archetecture info can be found). Because there are many academic debate about the shortcoming of ATM to support, I just want to see in the real world, why and how the operator/testbed do it. Can any friend give recommend me some URL, or article on this, such as of UUnet or Sprint? Thanks. Yu Ning. ----------------------------------------------------------------------* Yu Ning ATM R&D Center BUPT (Beijing U. of Posts&Telecom) Beijing (ZIP: 100876, MBox: 147#), P. R. China Tel:86-10-62283123; Fax:86-10-62283124 mailto:yuning@mindless.com or yuning@263.net -------------------------------------------------------------------------