A Unified Approach to Inter-Domain Multiple-Tos Routing

今天的互联网已经从一个基于层次结构的模型演变为一个主要基于丰富的互联网络的模型。由于拓扑结构的这种变化，除了互联网目前正在经历的指数级增长之外，迫切需要新的协议来支持基于策略（PB）和/或服务类型（TOS）路由流量的能力，以及在内存、计算、以及为流量的自适应路由提供所需的带宽资源。该提案通过结合当前三种路由协议中的最佳协议来解决这些需求。边界网关协议（BGP）最初是在NSFNET骨干网上实现的，作为对20世纪80年代后期需要一个新的外部网关协议的直接响应，以处理互联网规模的增加和开始出现的非分层对等网络。它基于路径向量路由模型，该模型使用每个网络附带策略的静态路由，旨在用于基于ip的网络。目前，主要路由供应商正在其产品中对其进行调整和实现。域间路由协议（IDRP）是具有附加功能的BGP，并通过CLNP在OSI世界中使用。IDRP非常接近通过其最后一次国际标准投票，然后将成为ISO/CCITT标准。它的出现将对美国GOSIP兼容网络的部署非常有帮助。域间策略路由（Inter Domain Policy Routing， IDPR）是一种模型，除了源要求的策略或TOS外，还允许根据传输网络支持的策略和TOS预先选择数据包将传输的网络。这种能力是许多联邦机构需要的，以便根据安全性、成本因素、保证多媒体带宽和实时实验控制来选择网络路径，此外还为机构提供实施其可接受的使用政策所需的工具。IDPR使用动态安装路由来实现其目标。BGP、IDRP和IDPR的组合将提供最好的世界。利用BGP/IDRP中的聚合特性可以节省资源，从而减少路由表的大小，减少计算路由所需的计算周期，减少传输路由信息所需的带宽。此外，将提供IDPR所具有的灵活性，以便处理诸如联邦机构所规定的特殊情况，并提供服务质量和服务支助类型。该提案旨在以一种不需要大规模更换现有技术和设备的方式，在目前部署的基础设施和协议的基础上进行建设，从而提供向具有增强能力的互联网络的分阶段演进。

The Internet today has evolved from a model based on a hierarchy to one mainly based on a richly interconnected mesh. Due to this change in topology, in addition to the exponential growth the Internet is currently experiencing, there exists a dire need for new protocols that support both the ability to route traffic based on policy (PB) and/or type of service (TOS) and the ability to scale well with respect to the memory, computational, and bandwidth resources necessary to provide for adaptive routing of traffic. This proposal addresses these requirements by combining the best of three current routing protocols. The Border Gateway Protocol (BGP) was first implemented on the NSFNET backbone as a direct response to the need for a new exterior gateway protocol in the late 1980s to handle the increase in size of the Internet and the non-hierarchical peering that was beginning to appear. It is based on a path-vector routing model which uses static routes with accompanying policies per network and is intended for use with IP-based networks. It is currently being adapted and implemented by major routing vendors in their products. The Inter Domain Routing Protocol (IDRP) is BGP with additional capabilities and adapted for use in the OSI world using CLNP. IDRP is very close to passing its last international standards vote and will then be an ISO/CCITT standard. Its emergence will be very helpful in the deployment of U.S. GOSIP compliant networks. The Inter Domain Policy Routing (IDPR) is a model that allows for the pre-selection of the networks a packet will transit based on the policies and TOS supported by the transit networks in addition to the policies or TOS required by the source. This capability is one that many Federal agencies need in order to select network paths based on security, cost factors, guaranteed bandwidth for multi-media and real time experimental control, in addition to providing the agencies with the tools necessary for implementing their acceptable use policies. The IDPR uses dynamic installation of routes to accomplish its goals. The combination of BGP, IDRP, and IDPR would provide the best of all worlds. Economy of resources would be gained using the aggregation features found in BGP/IDRP, thereby reducing routing table sizes, reducing the computational cycles required to calculate routes, and the bandwidth necessary for transmitting the routing information. In addition, the flexibility found in IDPR, required to handle special cases such as those defined by the federal agencies, and both quality of service and type of service support will be provided. This proposal aims at building on the currently deployed infrastructure and protocols in a manner that would not require a mass scale replacement of current technologies and equipment, and therefore provide for a phased evolution to an Internetwork with enhanced capabilities.