BRAS是城域网中用户接入的终结点和基础服务的提供点,也是城域网虚拟化的切入点。本文在介绍目前运营商城域网面临的挑战基础上,结合vBRAS设备演进形态,分析城域网引入vBRAS的价值和思路。研究引入vBRAS承载小流量大并发业务的解决方案。 BRAS is the metropolitan area network users access the endpoint and the basis for the provision of services, but also MAN entry-point virtualization. Based on the introduction of the current challenges of metro MANs and the evolution of vBRAS equipment, this paper analyzes the value and ideas of vBRAS introduction in MAN. Research into the vBRAS bearer small traffic concurrent services solution.