IP城域网有效运营的关键是业务控制层,一般有BRAS、SR等设备,现在有越来越多的业务靠统一功能的BSR设备承载,其提供PPPOE、IPOE、静态IP专线、MPLS VPN等业务。现有业务控制层设备大多数是利用单节点布置的形式,这种方式存在潜在的隐患问题,在设备组网可靠性问题需要多做考虑 The key to effective operation of an IP MAN is the service control layer. Generally, there are devices such as BRAS and SR. More and more businesses now rely on a unified BSR device to provide PPPOE, IPOE, static IP leased line, MPLS VPN, etc. business. Most of the existing service control layer devices are in the form of a single node arrangement, which poses potential hidden problems. The reliability of the device networking needs more consideration