| 1. | The sgsns establish external connections via provincial backbone nodes
Sgsn通过省内骨干节点实现同外部的连接。 |
| 2. | During the initial stage of network construction , the provincial backbone network may have one or more backbone nodes depending on capacity required
在网络建设初期，省骨干网根据容量需要可以有一个或多个骨干节点。 |
| 3. | If demand for gprs service is high , there will be more than one backbone node in the province , responsible for the convergence of traffic from some of the parts
图5fratm方式的全省gprs示意图若gprs业务需求大，这时省内将会有多个骨干节点。 |
| 4. | If there is a backbone ip network , the gsn nodes are directly connected to it . if not , these backbone nodes can be connected on a pppfratm basis
当省内有ip骨干网时， gsn节点等直接连接到ip骨干网上，当没有ip骨干网时，可以用pppfratm等方式将各骨干节点连接起来。 |
| 5. | Between these backbone nodes interconnection with the structure of the meshed network is formed . the provincial backbone nodes are responsible for dns analysis and access to the national network
各骨干节点负责部分地区的业务汇聚，骨干节点之间形成网状网结构互连，省内骨干网负责dns解析和接入全国骨干网。 |
| 6. | The provincial network accesses to the nodes of the national backbone network via border routers ( brs ) , which are usually installed in pair connected respectively to different backbone nodes to ensure reliability
省网通过边界路由器（ br ）接入骨干网节点，一般边界路由器成对设置，分别接入不同的骨干节点以保证网络的可靠性。 |
| 7. | The sgsns and the ggsns in different local networks communicate either via an fratm network on a pvc basis or via routers at provincial backbone nodes ; so the network has a certain degree of flexibility
不同的本地网sgsn与ggsn之间的通信，既可以通过fratm网络以pvc的方式建立连接，也可以通过省内骨干节点的路由器进行转接，网络具有一定的灵活性。 |
| 8. | For the backbone nodes , high - capacity dacs4 - 4 - 1 cross connect equipment with stm - 1s as its basic interfaces is used . between the various equipment , stm - 1 connections are directly used instead of tens of 2 mbits connections so that large amounts of hw equipment , power consumption , connecting lines between shelves and fault rate can be reduced , while network redundancy can be improved
骨干节点采用以stm 1为基本接口的大容量dacs4 - 4 - 1交叉机。各种设备之间直接使用stm - 1连接，不再使用几十个2mbits连接，可以大大减少设备硬件数量，降低电源消耗，机架之间连接线显著减少，降低故障发生率，提高网络冗余度，也可以降低建设和维护成本。 |
