现有隧道传输只考虑异构网络基本连通性,是一种分段独立实施路由选择的路由模型,没能对端到端跨越异构网络的传输路径进行一体化考虑.针对边缘网到支撑网的多宿主连接网络环境,提出了一种跨异构网络的一体化路由模型URM(Unified Routing Model).URM模型采用参考度量实现对异构网络路由优劣的统一描述,利用BGP协议扩展实现参考度量的传递,并设计了参考度量与传统度量的转换方法.URM模型实施时影响范围很小,只需对隧道网关进行简单改造即可完成,最终的一体化路由机制也是透明地利用现有路由机制完成.URM模型会给异构网关和边缘网路由器带来更多的信息存储,但其优势却非常明显,在实现端到端一体化最优路由选择的同时,增加了隧道传输的可用路径并提高了隧道传输可靠性.仿真实验及真实设备组网实验验证了URM模型的一体化路由选择能力及路由收敛能力.
In the interconnection scenarios between heterogeneous networks,the existing tunneling technique only considers basic connection requirements,which leads to an isolated routing model assembled by multiple fragmental routing phases.Consequently,comprehensive considerations of end-to-end routing across multiple heterogeneous networks are lacking.In this article,we propose a unified routing model(URM)which targets to the circumstance of edge multi-homing accessing to backbone networks.URM first introduces a referenced metric to uniformly describe the routing quality in heterogeneous networks.Then,it extends the BGP protocol to carry these referenced metrics and designs the conversion method between the referenced metric and the traditional metric.Eventually,with a minor modification in tunnel gateways,URM can transparently provide the optimal integrated routing service based on existing routing mechanisms.Besides,it can increase the path number and reliability of tunneling transmission.Simulation and real experiments both prove its ability with a fast convergence speed.