MSAP（Multi-Service Access Platform） is able to prompt the convergence among business

technology and networking.It has strong application prospects for dedicated line access for key accounts.Meanwhile for MSAP in key account access.some new requirements should be considered for transmission network planning and designing.Based on the MASP mechanism and current access network environment

the application models in the centre office side and the client side are presented and analyzed in this paper.With their clear and independent feature each model can be combined flexibly for actual demand in the key account and good solution for cost-effective planning and implementation of key account leased line access

and well adapted to the complex and changing network environment.